1 Boolean Operations {#specification__boolean_operations}
2 =========================
6 @section specification__boolean_1 Introduction
8 Boolean operations are used to create new shapes from the combinations of two groups of shapes.
9 This document provides a comprehensive description of the algorithms in the Boolean Operations Component as it is implemented in Open CASCADE Technology. The Boolean Component contains:
11 * General Fuse Operator (GFA),
12 * Boolean Operator (BOA),
13 * Section Operator (SA),
14 * Splitter Operator (SPA).
16 GFA is the base algorithm for BOA, SPA, SA.
18 GFA has a history-based architecture designed to allow using OCAF naming functionality. The architecture of GFA is expandable, that allows creating new algorithms basing on it.
21 @section specification__boolean_2 Overview
23 @subsection specification__boolean_2_1 Operators
25 @subsubsection specification__boolean_2_1_1 Boolean operator
27 The Boolean operator provides the following operations between two groups *Objects* and *Tools*:
28 * FUSE - Union of two groups;
29 * COMMON - Intersection of two groups;
30 * CUT - Difference between two groups.
32 Each group consists of an arbitrary number of arguments in terms of *TopoDS_Shape*.
34 The operator can be represented as:
36 <i>R<sub>B</sub>=B<sub>j</sub> (G<sub>1</sub>, G<sub>2</sub>),</i>
39 * *R<sub>B</sub>* -- result of the operation;
40 * *B<sub>j</sub>* -- operation of type *j* (Common, Fuse, Cut);
41 * *G<sub>1</sub>={S<sub>11</sub>, S<sub>12</sub> ... S<sub>1n1</sub>}* group of arguments (Objects);
42 * *G<sub>2</sub>={S<sub>21</sub>, S<sub>22</sub> ... S<sub>2n2</sub>}* group of arguments (Tools);
43 * *n<sub>1</sub>* -- Number of arguments in *Objects* group;
44 * *n<sub>2</sub>* -- Number of arguments in *Tools* group.
47 **Note** There is an operation *Cut21*, which is an extension for forward Cut operation, i.e <i>Cut21=Cut(G2, G1)</i>.
49 For more details see @ref specification__boolean_9 "Boolean Operations Algorithm" section.
51 @subsubsection specification__boolean_2_1_2 General Fuse operator
53 The General fuse operator can be applied to an arbitrary number of arguments in terms of *TopoDS_Shape*.
55 The GFA operator can be represented as:
57 <i>R<sub>GF</sub> = GF (S<sub>1</sub>, S<sub>2</sub> ... S<sub>n</sub>), </i>
60 * *R<sub>GF</sub>* -- result of the operation,
61 * *S<sub>1</sub>, S<sub>2</sub> ... S<sub>n</sub>* -- arguments of the operation,
62 * *n* -- number of arguments.
64 The result of the Boolean operator, *R<sub>B</sub>*, can be obtained from *R<sub>GF</sub>*.
66 For example, for two arguments *S<sub>1</sub>* and *S<sub>2</sub>* the result *R<sub>GF</sub>* is
68 <i>R<sub>GF</sub> = GF (S<sub>1</sub>, S<sub>2</sub>) = S<sub>p1</sub> + S<sub>p2</sub> + S<sub>p12</sub></i>
70 @figure{/specification/boolean_operations/images/operations_image001.svg,"Operators",320}
72 This Figure shows that
73 * <i>B<sub>common</sub> (S<sub>1</sub>, S<sub>2</sub>) = S<sub>p12</sub>;</i>
74 * <i>B<sub>cut12</sub> (S<sub>1</sub>, S<sub>2</sub>) = S<sub>p1</sub>;</i>
75 * <i>B<sub>cut21</sub> (S<sub>1</sub>, S<sub>2</sub>) = S<sub>p2</sub>;</i>
76 * <i>B<sub>fuse</sub> (S<sub>1</sub>, S<sub>2</sub>) = S<sub>p1</sub>+S<sub>p2</sub>+S<sub>p12</sub></i>
78 <i>R<sub>GF</sub>=GF (S<sub>1</sub>, S<sub>2</sub>) = B<sub>fuse</sub> = B<sub>common</sub>+ B<sub>cut12</sub>+ B<sub>cut21</sub>.</i>
80 The fact that *R<sub>GF</sub>* contains the components of *R<sub>B</sub>* allows considering GFA as the general case of BOA. So it is possible to implement BOA as a subclass of GFA.
82 For more details see @ref specification__boolean_7 "General Fuse Algorithm" section.
84 @subsubsection specification__boolean_2_1_3 Splitter operator
86 The Splitter operator can be applied to an arbitrary number of arguments in terms of *TopoDS_Shape*. The arguments are divided into two groups: *Objects* and *Tools*. The result of *SPA* contains all parts that belong to the *Objects* but does not contain the parts that belong to the *Tools*.
88 The *SPA* operator can be represented as follows:
90 <i>R<sub>SPA</sub>=SPA (G<sub>1</sub>, G<sub>2</sub>),</i>
92 * <i>R<sub>SPA</sub></i> -- is the result of the operation;
93 * *G<sub>1</sub>={S<sub>11</sub>, S<sub>12</sub> ... S<sub>1n1</sub>}* group of arguments (*Objects*);
94 * *G<sub>2</sub>={S<sub>21</sub>, S<sub>22</sub> ... S<sub>2n2</sub>}* group of arguments (*Tools*);
95 * *n<sub>1</sub>* -- Number of arguments in *Objects* group;
96 * *n<sub>2</sub>* -- Number of arguments in *Tools* group.
98 The result *R<sub>SPA</sub>* can be obtained from *R<sub>GF</sub>* .
100 For example, for two arguments *S<sub>1</sub>* and *S<sub>2</sub>* the result *R<sub>SPA</sub>* is
102 <i>R<sub>SPA</sub>=SPA(S<sub>1</sub>,S<sub>2</sub>)=S<sub>p1</sub>+S<sub>p12</sub>.</i>
104 In case when all arguments of the *SPA* are *Objects* and there are no *Tools*, the result of *SPA* is equivalent to the result of *GFA*.
106 For example, when *G<sub>1</sub>* consists of shapes *S<sub>1</sub>* and *S<sub>2</sub>* the result of *SPA* is
108 <i>R<sub>SPA</sub>=SPA(S<sub>1</sub>, S<sub>2</sub>) = S<sub>p1</sub> + S<sub>p2</sub> + S<sub>p12</sub> = GF (S<sub>1</sub>, S<sub>2</sub>)</i>
110 The fact that the *R<sub>GF</sub>* contains the components of *R<sub>SPA</sub>* allows considering *GFA* as the general case of *SPA*. Thus, it is possible to implement *SPA* as a subclass of *GFA*.
112 For more details see @ref specification__boolean_8 "Splitter Algorithm" section.
114 @subsubsection specification__boolean_2_1_4 Section operator
116 The Section operator *SA* can be applied to arbitrary number of arguments in terms of *TopoDS_Shape*. The result of *SA* contains vertices and edges in accordance with interferences between the arguments
117 The SA operator can be represented as follows:
118 <i>R<sub>SA</sub>=SA(S1, S2… Sn)</i>, where
119 * <i>R<sub>SA</sub></i> -- the operation result;
120 * <i>S1, S2 ... Sn</i> -- the operation arguments;
121 * *n* -- the number of arguments.
123 For more details see @ref specification__boolean_10a "Section Algorithm" section.
125 @subsection specification__boolean_2_2 Parts of algorithms
127 GFA, BOA, SPA and SA have the same Data Structure (DS). The main goal of the Data Structure is to store all necessary information for input data and intermediate results.
129 The operators consist of two main parts:
130 * Intersection Part (IP). The main goal of IP is to compute the interferences between sub-shapes of arguments. The IP uses DS to retrieve input data and store the results of intersections.
131 * Building Part (BP). The main goal of BP is to build required result of an operation. This part also uses DS to retrieve data and store the results.
133 As it follows from the definition of operator results, the main differences between GFA, BOA, SPA and SA are in the Building Part. The Intersection Part is the same for the algorithms.
135 @section specification__boolean_3 Terms and Definitions
137 This chapter provides the background terms and definitions that are necessary to understand how the algorithms work.
139 @subsection specification__boolean_3_1 Interferences
141 There are two groups of interferences.
143 At first, each shape having a boundary representation (vertex, edge, face) has an internal value of geometrical tolerance. The shapes interfere with each other in terms of their tolerances. The shapes that have a boundary representation interfere when there is a part of 3D space where the distance between the underlying geometry of shapes is less or equal to the sum of tolerances of the shapes. Three types of shapes: vertex, edge and face -- produce six types of **BRep interferences:**
151 At second, there are interferences that occur between a solid *Z1* and a shape *S2* when *Z1* and *S2* have no BRep interferences but *S2* is completely inside of *Z1*. These interferences are **Non-BRep interferences**. There are four possible cases:
157 @subsubsection specification__boolean_3_1_1 Vertex/Vertex interference
159 For two vertices *Vi* and *Vj*, the distance between their corresponding 3D points is less than the sum of their tolerances *Tol(Vi)* and *Tol(Vj)*.
161 @figure{/specification/boolean_operations/images/operations_image002.svg,"Vertex/vertex interference",420}
163 The result is a new vertex *Vn* with 3D point *Pn* and tolerance value <i>Tol(Vn)</i>.
165 The coordinates of *Pn* and the value <i>Tol(Vn)</i> are computed as the center and the radius of the sphere enclosing the tolerance spheres of the source vertices <i>(V1, V2)</i>.
167 @subsubsection specification__boolean_3_1_2 Vertex/Edge interference
169 For a vertex *Vi* and an edge *Ej*, the distance *D* between 3D point of the vertex and its projection on the 3D curve of edge *Ej* is less or equal than sum of tolerances of vertex *Tol(Vi)* and edge *Tol(Ej)*.
171 @figure{/specification/boolean_operations/images/operations_image003.svg,"Vertex/edge interference",420}
173 The result is vertex *Vi* with the corresponding tolerance value <i>Tol(Vi)=Max(Tol(Vi), D+Tol(Ej))</i>, where <i>D = distance (Pi, PPi)</i>;
175 and parameter *t<sub>i</sub>* of the projected point *PPi* on 3D curve *Cj* of edge *Ej*.
177 @subsubsection specification__boolean_3_1_3 Vertex/Face interference
179 For a vertex *Vi* and a face *Fj* the distance *D* between 3D point of the vertex and its projection on the surface of the face is less or equal than sum of tolerances of the vertex *Tol(Vi)* and the face *Tol(Fj)*.
181 @figure{/specification/boolean_operations/images/operations_image004.svg,"Vertex/face interference",420}
183 The result is vertex *Vi* with the corresponding tolerance value <i>Tol(Vi)=Max(Tol(Vi), D+Tol(Fj))</i>, where <i>D = distance (Pi, PPi)</i>
185 and parameters <i>u<sub>i</sub>, v<sub>i</sub></i> of the projected point *PPi* on surface *Sj* of face *Fj*.
187 @subsubsection specification__boolean_3_1_4 Edge/Edge interference
189 For two edges *Ei* and *Ej* (with the corresponding 3D curves *Ci* and *Cj*) there are some places where the distance between the curves is less than (or equal to) sum of tolerances of the edges.
191 Let us examine two cases:
193 In the first case two edges have one or several common parts of 3D curves in terms of tolerance.
195 @figure{/specification/boolean_operations/images/operations_image005.svg,"Edge/edge interference: common parts",420}
198 * Parametric range <i>[t<sub>i1</sub>, t<sub>i2</sub> ]</i> for 3D curve *Ci* of edge *Ei*.
199 * Parametric range <i>[t<sub>j1</sub>, t<sub>j2</sub> ]</i> for 3D curve *Cj* of edge *Ej*.
201 In the second case two edges have one or several common points in terms of tolerance.
203 @figure{/specification/boolean_operations/images/operations_image006.svg,"Edge/edge interference: common points",420}
205 The result is a new vertex *Vn* with 3D point *Pn* and tolerance value *Tol(Vn)*.
207 The coordinates of *Pn* and the value *Tol(Vn)* are computed as the center and the radius of the sphere enclosing the tolerance spheres of the corresponding nearest points *Pi*, *Pj* of 3D curves *Ci*, *Cj* of source edges *Ei*, *Ej*.
209 * Parameter *t<sub>i</sub>* of *Pi* for the 3D curve *Ci*.
210 * Parameter *t<sub>j</sub>* of *Pj* for the 3D curve *Cj*.
212 @subsubsection specification__boolean_3_1_5 Edge/Face interference
214 For an edge *Ei* (with the corresponding 3D curve *Ci*) and a face *Fj* (with the corresponding 3D surface *Sj*) there are some places in 3D space, where the distance between *Ci* and surface *Sj* is less than (or equal to) the sum of tolerances of edge *Ei* and face *Fj*.
216 Let us examine two cases:
218 In the first case Edge *Ei* and Face *Fj* have one or several common parts in terms of tolerance.
220 @figure{/specification/boolean_operations/images/operations_image007.svg,"Edge/face interference: common parts",420}
222 The result is a parametric range <i>[t<sub>i1</sub>, t<sub>i2</sub>]</i> for the 3D curve *Ci* of the edge *Ei*.
224 In the second case Edge *Ei* and Face *Fj* have one or several common points in terms of tolerance.
226 @figure{/specification/boolean_operations/images/operations_image008.svg,"Edge/face interference: common points",420}
228 The result is a new vertex *Vn* with 3D point *Pn* and tolerance value *Tol(Vn)*.
230 The coordinates of *Pn* and the value *Tol(Vn)* are computed as the center and the radius of the sphere enclosing the tolerance spheres of the corresponding nearest points *Pi*, *Pj* of 3D curve *Ci* and surface *Sj* of source edges *Ei*, *Fj*.
232 * Parameter *t<sub>i</sub>* of *Pi* for the 3D curve *Ci*.
233 * Parameters *u<sub>i</sub>* and *v<sub>i</sub>* of the projected point *PPi* on the surface *Sj* of the face *Fj*.
235 @subsubsection specification__boolean_3_1_6 Face/Face Interference
237 For a face *Fi* and a face *Fj* (with the corresponding surfaces *Si* and *Sj*) there are some places in 3D space, where the distance between the surfaces is less than (or equal to) sum of tolerances of the faces.
239 @figure{/specification/boolean_operations/images/operations_image009.svg,"Face/face interference: common curves",418}
241 In the first case the result contains intersection curves *C<sub>ijk</sub> (k = 0, 1, 2…k<sub>N</sub>,* where *k<sub>N</sub>* is the number of intersection curves with corresponding values of tolerances *Tol(C<sub>ijk</sub>)*.
243 @figure{/specification/boolean_operations/images/operations_image010.svg,"Face/face interference: common points",305}
245 In the second case Face *Fi* and face *Fj* have one or several new vertices *V<sub>ijm</sub>*, where <i>m=0,1,2, ... mN, mN </i> is the number of intersection points.
247 The coordinates of a 3D point *P<sub>ijm</sub>* and the value *Tol(V<sub>ijm</sub>)* are computed as the center and the radius of the sphere enclosing the tolerance spheres of the corresponding nearest points *Pi*, *Pj* of the surface *Si*, *Sj* of source shapes *Fi*, *Fj*.
249 * Parameters *u<sub>j</sub>*, *v<sub>j</sub>* belong to point *PPj* projected on surface *Sj* of face *Fj*.
250 * Parameters *u<sub>i</sub>* and *v<sub>i</sub>* belong to point *PPi* projected on surface *Si* of face *Fi*.
252 @subsubsection specification__boolean_3_1_7 Vertex/Solid Interference
254 For a vertex *Vi* and a solid *Zj* there is Vertex/Solid interference if the vertex *Vi* has no BRep interferences with any sub-shape of *Zj* and *Vi* is completely inside the solid *Zj*.
256 @figure{/specification/boolean_operations/images/operations_image060.png,"Vertex/Solid Interference",220}
258 @subsubsection specification__boolean_3_1_8 Edge/Soild Interference
260 For an edge *Ei* and a solid *Zj* there is Edge/Solid interference if the edge *Ei* and its sub-shapes have no BRep interferences with any sub-shape of *Zj* and *Ei* is completely inside the solid *Zj*.
262 @figure{/specification/boolean_operations/images/operations_image061.png,"Edge/Solid Interference",220}
264 @subsubsection specification__boolean_3_1_9 Face/Soild Interference
266 For a face *Fi* and a solid *Zj* there is Face/Solid interference if the face *Fi* and its sub-shapes have no BRep interferences with any sub-shape of *Zj* and *Fi* is completely inside the solid *Zj*.
268 @figure{/specification/boolean_operations/images/operations_image062.png,"Face/Solid Interference",220}
270 @subsubsection specification__boolean_3_1_10 Solid/Soild Interference
272 For a solid *Zi* and a solid *Zj* there is Solid/Solid interference if the solid *Zi* and its sub-shapes have no BRep interferences with any sub-shape of *Zj* and *Zi* is completely inside the solid *Zj*.
274 @figure{/specification/boolean_operations/images/operations_image063.png,"Solid/Solid Interference",220}
277 @subsubsection specification__boolean_3_1_11 Computation Order
279 The interferences between shapes are computed on the basis of increasing of the dimension value of the shape in the following order:
291 This order allows avoiding the computation of redundant interferences between upper-level shapes *Si* and *Sj* when there are interferences between lower sub-shapes *Sik* and *Sjm*.
293 @subsubsection specification__boolean_3_1_12 Results
295 * The result of the interference is a shape that can be either interfered shape itself (or its part) or a new shape.
296 * The result of the interference is a shape with the dimension value that is less or equal to the minimal dimension value of interfered shapes. For example, the result of Vertex/Edge interference is a vertex, but not an edge.
297 * The result of the interference splits the source shapes on the parts each time as it can do that.
299 @subsection specification__boolean_3_2 Paves
301 The result of interferences of the type Vertex/Edge, Edge/Edge and Edge/Face in most cases is a vertex (new or old) lying on an edge.
303 The result of interferences of the type Face/Face in most cases is intersection curves, which go through some vertices lying on the faces.
305 The position of vertex *Vi* on curve *C* can be defined by a value of parameter <i>t<sub>i</sub></i> of the 3D point of the vertex on the curve.
306 Pave *PVi* on curve *C* is a structure containing the vertex *Vi* and correspondent value of the parameter <i>t<sub>i</sub></i> of the 3D point of the vertex on the curve. Curve *C* can be a 3D or a 2D curve.
308 @figure{/specification/boolean_operations/images/operations_image011.svg,"Paves",340}
310 Two paves *PV1* and *PV2* on the same curve *C* can be compared using the parameter value @code PV1 > PV2 if t1 > t2 @endcode
312 The usage of paves allows binding of the vertex to the curve (or any structure that contains a curve: edge, intersection curve).
315 @subsection specification__boolean_3_3 Pave Blocks
317 A set of paves *PVi (i=1, 2...nPV)*, where *nPV* is the number of paves] of curve *C* can be sorted in the increasing order using the value of parameter *t* on curve *C*.
319 A pave block *PBi* is a part of the object (edge, intersection curve) between neighboring paves.
321 @figure{/specification/boolean_operations/images/operations_image012.svg,"Pave Blocks",340}
323 Any finite source edge *E* has at least one pave block that contains two paves *PVb* and *PVe*:
324 * Pave *PVb* corresponds to the vertex *Vb* with minimal parameter <i>t<sub>b</sub></i> on the curve of the edge.
325 * Pave *PVe* corresponds to the vertex *Ve* with maximal parameter <i>t<sub>e</sub></i> on the curve of the edge.
327 @subsection specification__boolean_3_4 Shrunk Range
329 Pave block *PV* of curve *C* is bounded by vertices *V1* and *V2* with tolerance values *Tol(V1)* and *Tol(V2)*. Curve *C* has its own tolerance value *Tol(C)*:
330 * In case of edge, the tolerance value is the tolerance of the edge.
331 * In case of intersection curve, the tolerance value is obtained from an intersection algorithm.
333 @figure{/specification/boolean_operations/images/operations_image013.svg,"Shrunk Range",340}
335 The theoretical parametric range of the pave block is <i>[t1C, t2C]</i>.
337 The positions of the vertices *V1* and *V2* of the pave block can be different. The positions are determined by the following conditions:
339 Distance (P1, P1c) is equal or less than Tol(V1) + Tol(C)
340 Distance (P2, P2c) is equal or less than Tol(V2) + Tol(C)
342 The Figure shows that each tolerance sphere of a vertex can reduce the parametric range of the pave block to a range <i>[t1S, t2S]</i>. The range <i>[t1S, t2S]</i> is the shrunk range of the pave block.
344 The shrunk range of the pave block is the part of 3D curve that can interfere with other shapes.
346 @subsection specification__boolean_3_5 Common Blocks
348 The interferences of the type Edge/Edge, Edge/Face produce results as common parts.
350 In case of Edge/Edge interference the common parts are pave blocks that have different base edges.
352 @figure{/specification/boolean_operations/images/operations_image014.svg,"Common Blocks: Edge/Edge interference",340}
354 If the pave blocks <i>PB<sub>1</sub>, PB<sub>2</sub>…PB<sub>NbPB</sub></i> , where *NbPB* is the number of pave blocks have the same bounding vertices and geometrically coincide, the pave blocks form common block *CB*.
357 In case of Edge/Face interference the common parts are pave blocks lying on a face(s).
359 @figure{/specification/boolean_operations/images/operations_image015.svg,"Common Blocks: Edge/Face interference",265}
361 If the pave blocks *PBi* geometrically coincide with a face *Fj*, the pave blocks form common block *CB*.
363 In general case a common block *CB* contains:
364 * Pave blocks *PBi (i=0,1,2, 3… NbPB)*.
365 * A set of faces *Fj (j=0,1... NbF), NbF* -- number of faces.
368 @subsection specification__boolean_3_6 FaceInfo
370 The structure *FaceInfo* contains the following information:
371 * Pave blocks that have state **In** for the face;
372 * Vertices that have state **In** for the face;
373 * Pave blocks that have state **On** for the face;
374 * Vertices that have state **On** for the face;
375 * Pave blocks built up from intersection curves for the face;
376 * Vertices built up from intersection points for the face.
378 @figure{/specification/boolean_operations/images/operations_image016.svg,"Face Info",420}
380 In the figure, for face *F1*:
381 * Pave blocks that have state **In** for the face: *PB<sub>in1</sub>*.
382 * Vertices that have state **In** for the face: *V<sub>in1</sub>*.
383 * Pave blocks that have state **On** for the face: *PB<sub>on11</sub>*, *PB<sub>on12</sub>*, *PB<sub>on2</sub>*, *PB<sub>on31</sub>*, *PB<sub>on32</sub>*, *PB<sub>on4</sub>*.
384 * Vertices that have state **On** for the face: *V1, V2, V3, V4, V5, V6*.
385 * Pave blocks built up from intersection curves for the face: *PB<sub>sc1</sub>*.
386 * Vertices built up from intersection points for the face: none
389 @section specification__boolean_4 Data Structure
391 Data Structure (DS) is used to:
392 * Store information about input data and intermediate results;
393 * Provide the access to the information;
394 * Provide the links between the chunks of information.
396 This information includes:
403 Data Structure is implemented in the class *BOPDS_DS*.
405 @subsection specification__boolean_4_1 Arguments
407 The arguments are shapes (in terms of *TopoDS_Shape*):
408 * Number of arguments is unlimited.
409 * Each argument is a valid shape (in terms of *BRepCheck_Analyzer*).
410 * Each argument can be of one of the following types (see the Table):
412 | No | Type | Index of Type |
413 | :----- | :----- | :----- |
415 | 2 | COMPSOLID | 1 |
423 * The argument of type *0 (COMPOUND)* can include any number of shapes of an arbitrary type (0, 1…7).
424 * The argument should not be self-interfered, i.e. all sub-shapes of the argument that have geometrical coincidence through any topological entities (vertices, edges, faces) must share these entities.
425 * There are no restrictions on the type of underlying geometry of the shapes. The faces or edges of arguments *S<sub>i</sub>* can have underlying geometry of any type supported by Open CASCADE Technology modeling algorithms (in terms of *GeomAbs_CurveType* and *GeomAbs_SurfaceType*).
426 * The faces or edges of the arguments should have underlying geometry with continuity that is not less than C1.
428 @subsection specification__boolean_4_2 Shapes
430 The information about Shapes is stored in structure *BOPDS_ShapeInfo*. The objects of type *BOPDS_ShapeInfo* are stored in the container of array type. The array allows getting the access to the information by an index (DS index).
431 The structure *BOPDS_ShapeInfo* has the following contents:
435 | :-------- | :----- |
436 | *myShape* | Shape itself |
437 | *myType* | Type of shape |
438 | *myBox* | 3D bounding box of the shape |
439 | *mySubShapes* | List of DS indices of sub-shapes |
440 | *myReference* | Storage for some auxiliary information |
441 | *myFlag* | Storage for some auxiliary information |
443 @subsection specification__boolean_4_3 Interferences
445 The information about interferences is stored in the instances of classes that are inherited from class <i>BOPDS_Interf</i>.
449 | *BOPDS_Interf* | Root class for interference |
450 | *Index1* | DS index of the shape 1 |
451 | *Index2* | DS index of the shape 2 |
452 | *BOPDS_InterfVV* | Storage for Vertex/Vertex interference |
453 | *BOPDS_InterfVE* | Storage for Vertex/Edge interference |
454 | *myParam* | The value of parameter of the point of the vertex on the curve of the edge |
455 | *BOPDS_InterfVF* | Storage for Vertex/Face interference |
456 | *myU, myV* | The value of parameters of the point of the vertex on the surface of the face |
457 | *BOPDS_InterfEE* | Storage for Edge/Edge interference |
458 | *myCommonPart* | Common part (in terms of *IntTools_CommonPart* ) |
459 | *BOPDS_InterfEF* | Storage for Edge/Face interference |
460 | *myCommonPart* | Common part (in terms of *IntTools_CommonPart* ) |
461 | *BOPDS_InterfFF* | Storage for Face/Face interference |
462 | *myTolR3D, myTolR2D* | The value of tolerances of curves (points) reached in 3D and 2D |
463 | *myCurves* | Intersection Curves (in terms of *BOPDS_Curve*) |
464 | *myPoints* | Intersection Points (in terms of *BOPDS_Point*) |
465 | *BOPDS_InterfVZ* | Storage for Vertex/Solid interference |
466 | *BOPDS_InterfEZ* | Storage for Edge/Solid interference |
467 | *BOPDS_InterfFZ* | Storage for Face/Solid interference |
468 | *BOPDS_InterfZZ* | Storage for Solid/Solid interference |
474 The Figure shows inheritance diagram for *BOPDS_Interf* classes.
476 @figure{/specification/boolean_operations/images/operations_image017.svg,"BOPDS_Interf classes",420}
479 @subsection specification__boolean_4_4 Pave, PaveBlock and CommonBlock
481 The information about the pave is stored in objects of type *BOPDS_Pave*.
486 | *myIndex* | DS index of the vertex |
487 | *myParam* | Value of the parameter of the 3D point of vertex on curve. |
489 The information about pave blocks is stored in objects of type *BOPDS_PaveBlock*.
493 | *BOPDS_PaveBlock* | |
494 | *myEdge* | DS index of the edge produced from the pave block |
495 | *myOriginalEdge* | DS index of the source edge |
496 | *myPave1* | Pave 1 (in terms of *BOPDS_Pave*) |
497 | *myPave2* | Pave 2 (in terms of *BOPDS_Pave*) |
498 | *myExtPaves* | The list of paves (in terms of *BOPDS_Pave*) that is used to store paves lying inside the pave block during intersection process |
499 | *myCommonBlock* | The reference to common block (in terms of *BOPDS_CommonBlock*) if the pave block is a common block |
500 | *myShrunkData* | The shrunk range of the pave block |
502 * To be bound to an edge (or intersection curve) the structures of type *BOPDS_PaveBlock* are stored in one container of list type <i>(BOPDS_ListOfPaveBlock)</i>.
503 * In case of edge, all the lists of pave blocks above are stored in one container of array type. The array allows getting the access to the information by index of the list of pave blocks for the edge. This index (if exists) is stored in the field *myReference*.
505 The information about common block is stored in objects of type *BOPDS_CommonBlock*.
509 | *BOPDS_CommonBlock* | |
510 | *myPaveBlocks* | The list of pave blocks that are common in terms of @ref specification__boolean_3_5 "Common Blocks" |
511 | *myFaces* | The list of DS indices of the faces, on which the pave blocks lie. |
514 @subsection specification__boolean_4_5 Points and Curves
515 The information about intersection point is stored in objects of type *BOPDS_Point*.
520 | *myPnt* | 3D point |
521 | *myPnt2D1* | 2D point on the face1 |
522 | *myPnt2D2* | 2D point on the face2 |
524 The information about intersection curve is stored in objects of type *BOPDS_Curve*.
529 | *myCurve* | The intersection curve (in terms of *IntTools_Curve* ) |
530 | *myPaveBlocks* | The list of pave blocks that belong to the curve |
531 | *myBox* | The bounding box of the curve (in terms of *Bnd_Box* ) |
533 @subsection specification__boolean_4_6 FaceInfo
534 The information about *FaceInfo* is stored in a structure *BOPDS_FaceInfo*.
535 The structure *BOPDS_FaceInfo* has the following contents.
539 | *BOPDS_FaceInfo* | |
540 | *myPaveBlocksIn* | Pave blocks that have state In for the face |
541 | *myVerticesIn* | Vertices that have state In for the face |
542 | *myPaveBlocksOn* | Pave blocks that have state On for the face |
543 | *myVerticesOn* | Vertices that have state On for the face |
544 | *myPaveBlocksSc* | Pave blocks built up from intersection curves for the face |
545 | *myVerticesSc* | Vertices built up from intersection points for the face +
547 The objects of type *BOPDS_FaceInfo* are stored in one container of array type. The array allows getting the access to the information by index. This index (if exists) is stored in the field *myReference*.
549 @section specification__boolean_root_classes Root Classes
551 @subsection specification__boolean_root_classes_1 Class BOPAlgo_Options
552 The class *BOPAlgo_Options* provides the following options for the algorithms:
553 * Set the appropriate memory allocator;
554 * Check the presence of the Errors and Warnings;
555 * Turn on/off the parallel processing;
556 * Set the additional tolerance for the operation;
557 * Break the operations by user request;
558 * Usage of Oriented Bounding boxes in the operation.
560 @subsection specification__boolean_root_classes_2 Class BOPAlgo_Algo
562 The class *BOPAlgo_Algo* provides the base interface for all algorithms:
563 * Perform the operation;
564 * Check the input data;
567 @section specification__boolean_5 Intersection Part
569 Intersection Part (IP) is used to
570 * Initialize the Data Structure;
571 * Compute interferences between the arguments (or their sub-shapes);
572 * Compute same domain vertices, edges;
574 * Build section edges;
576 * Store all obtained information in DS.
578 IP is implemented in the class *BOPAlgo_PaveFiller*.
580 @figure{/specification/boolean_operations/images/operations_image064.png,"Diagram for Class BOPAlgo_PaveFiller",230}
582 The description provided in the next paragraphs is coherent with the implementation of the method *BOPAlgo_PaveFiller::Perform()*.
584 @subsection specification__boolean_5_1 Initialization
585 The input data for the step is the Arguments. The description of initialization step is shown in the Table.
587 | No | Contents | Implementation |
588 | :--- | :----- | :----- |
589 | 1 | Initialization the array of shapes (in terms of @ref specification__boolean_4_2 "Shapes"). Filling the array of shapes. | *BOPDS_DS::Init()* |
590 | 2 | Initialization the array pave blocks (in terms of @ref specification__boolean_4_4 "Pave, PaveBlock, CommonBlock") | *BOPDS_DS::Init()* |
591 | 3 | Initialization of intersection Iterator. The intersection Iterator is the object that computes intersections between sub-shapes of the arguments in terms of bounding boxes. The intersection Iterator provides approximate number of the interferences for given type (in terms of @ref specification__boolean_3_1 "Interferences") | *BOPDS_Iterator* |
592 | 4 | Initialization of intersection Context. The intersection Context is an object that contains geometrical and topological toolkit (classifiers, projectors, etc). The intersection Context is used to cache the tools to increase the algorithm performance. | *IntTools_Context* |
595 @subsection specification__boolean_5_2 Compute Vertex/Vertex Interferences
597 The input data for this step is the DS after the @ref specification__boolean_5_1 "Initialization". The description of this step is shown in the table :
600 | No | Contents | Implementation |
601 | :--- | :---- | :----- |
602 | 1 | Initialize array of Vertex/Vertex interferences. | *BOPAlgo_PaveFiller::PerformVV()* |
603 | 2 | Access to the pairs of interfered shapes <i>(nVi, nVj)k, k=0, 1…nk,</i> where *nVi* and *nVj* are DS indices of vertices *Vi* and *Vj* and *nk* is the number of pairs. | *BOPDS_Iterator* |
604 | 3 | Compute the connexity chains of interfered vertices *nV1C, nV2C… nVnC)k, C=0, 1…nCs*, where *nCs* is the number of the connexity chains | *BOPAlgo_Tools::MakeBlocksCnx()* |
605 | 4 | Build new vertices from the chains *VNc. C=0, 1…nCs.* | *BOPAlgo_PaveFiller::PerformVV()* |
606 | 5 | Append new vertices in DS. | *BOPDS_DS::Append()* |
607 | 6 | Append same domain vertices in DS. | *BOPDS_DS::AddShapeSD()* |
608 | 7 | Append Vertex/Vertex interferences in DS. | *BOPDS_DS::AddInterf()* |
610 * The pairs of interfered vertices are: <i>(nV11, nV12), (nV11, nV13), (nV12, nV13), (nV13, nV15), (nV13, nV14), (nV14, nV15), (nV21, nV22), (nV21, nV23), (nV22, nV23);</i>
611 * These pairs produce two chains: <i>(nV11, nV12, nV13, nV14, nV15)</i> and <i>(nV21, nV22, nV23);</i>
612 * Each chain is used to create a new vertex, *VN1* and *VN2*, correspondingly.
614 The example of connexity chains of interfered vertices is given in the image:
616 @figure{/specification/boolean_operations/images/operations_image018.svg,"Connexity chains of interfered vertices",394}
619 @subsection specification__boolean_5_3 Compute Vertex/Edge Interferences
621 The input data for this step is the DS after computing Vertex/Vertex interferences.
623 | No | Contents | Implementation |
624 | :--- | :--- | :--- |
625 | 1 | Initialize array of Vertex/Edge interferences | *BOPAlgo_PaveFiller::PerformVE()* |
626 | 2 | Access to the pairs of interfered shapes <i>(nVi, nEj)k k=0, 1…nk,</i> where *nVi* is DS index of vertex *Vi*, *nEj* is DS index of edge *Ej* and *nk* is the number of pairs. | *BOPDS_Iterator* |
627 | 3 | Compute paves. See @ref specification__boolean_3_1_2 "Vertex/Edge Interference" | *BOPInt_Context::ComputeVE()* |
628 | 4 | Initialize pave blocks for the edges *Ej* involved in the interference | *BOPDS_DS:: ChangePaveBlocks()* |
629 | 5 | Append the paves into the pave blocks in terms of @ref specification__boolean_4_4 "Pave, PaveBlock and CommonBlock" | *BOPDS_PaveBlock:: AppendExtPave()* |
630 | 6 | Append Vertex/Edge interferences in DS | *BOPDS_DS::AddInterf()* |
632 @subsection specification__boolean_5_4 Update Pave Blocks
633 The input data for this step is the DS after computing Vertex/Edge Interferences.
635 | No | Contents | Implementation |
636 | :--- | :---- | :--- |
637 | 1 | Each pave block PB containing internal paves is split by internal paves into new pave blocks *PBN1, PBN2… PBNn*. PB is replaced by new pave blocks *PBN1, PBN2… PBNn* in the DS. | *BOPDS_DS:: UpdatePaveBlocks()* |
639 @subsection specification__boolean_5_5 Compute Edge/Edge Interferences
641 The input data for this step is the DS after updating Pave Blocks.
643 | No | Contents | Implementation |
644 | :---- | :---- | :----- |
645 | 1 | Initialize array of Edge/Edge interferences | *BOPAlgo_PaveFiller::PerformEE()* |
646 | 2 | Access to the pairs of interfered shapes <i>(nEi, nEj)k, k=0, 1…nk,</i> where *nEi* is DS index of the edge *Ei*, *nEj* is DS index of the edge *Ej* and *nk* is the number of pairs. | *BOPDS_Iterator* |
647 | 3 | Initialize pave blocks for the edges involved in the interference, if it is necessary. | *BOPDS_DS:: ChangePaveBlocks()* |
648 | 4 | Access to the pave blocks of interfered shapes: <i>(PBi1, PBi2…PBiNi)</i> for edge *Ei* and <i>(PBj1, PBj2…PBjNj)</i> for edge *Ej* | *BOPAlgo_PaveFiller::PerformEE()* |
649 | 5 | Compute shrunk data for pave blocks in terms of @ref specification__boolean_4_4 "Pave, PaveBlock and CommonBlock", if it is necessary. | *BOPAlgo_PaveFiller::FillShrunkData()* |
650 | 6 | Compute Edge/Edge interference for pave blocks *PBix* and *PBiy*. The result of the computation is a set of objects of type *IntTools_CommonPart* | *IntTools_EdgeEdge* |
651 | 7.1 | For each *CommonPart* of type *VERTEX:* Create new vertices *VNi (i =1, 2…,NbVN),* where *NbVN* is the number of new vertices. Intersect the vertices *VNi* using the steps Initialization and compute Vertex/Vertex interferences as follows: a) create a new object *PFn* of type *BOPAlgo_PaveFiller* with its own DS; b) use new vertices *VNi (i=1, 2…,NbVN), NbVN* as arguments (in terms of *TopoDs_Shape*) of *PFn*; c) invoke method *Perform()* for *PFn*. The resulting vertices *VNXi (i=1, 2…,NbVNX)*, where *NbVNX* is the number of vertices, are obtained via mapping between *VNi* and the results of *PVn*. | *BOPTools_Tools::MakeNewVertex()* |
652 | 7.2 | For each *CommonPart* of type *EDGE:* Compute the coinciding connexity chains of pave blocks <i>(PB1C, PB2C… PNnC)k, C=0, 1…nCs,</i> where *nCs* is the number of the connexity chains. Create common blocks <i>(CBc. C=0, 1…nCs)</i> from the chains. Attach the common blocks to the pave blocks. | *BOPAlgo_Tools::PerformCommonBlocks()* |
653 | 8 | Post-processing. Append the paves of *VNXi* into the corresponding pave blocks in terms of @ref specification__boolean_4_4 "Pave, PaveBlock and CommonBlock" | *BOPDS_PaveBlock:: AppendExtPave()* |
654 | 9 | Split common blocks CBc by the paves. | *BOPDS_DS:: UpdateCommonBlock()* |
655 | 10 | Append Edge/Edge interferences in the DS. | *BOPDS_DS::AddInterf()* |
657 The example of coinciding chains of pave blocks is given in the image:
659 @figure{/specification/boolean_operations/images/operations_image019.png,"Coinciding chains of pave blocks",420}
661 * The pairs of coincided pave blocks are: <i>(PB11, PB12), (PB11, PB13), (PB12, PB13), (PB21, PB22), (PB21, PB23), (PB22, PB23).</i>
662 * The pairs produce two chains: <i>(PB11, PB12, PB13)</i> and <i>(PB21, PB22, PB23).</i>
664 @subsection specification__boolean_5_6 Compute Vertex/Face Interferences
666 The input data for this step is the DS after computing Edge/Edge interferences.
668 | No | Contents | Implementation |
669 | :---- | :--- | :---- |
670 | 1 | Initialize array of Vertex/Face interferences | *BOPAlgo_PaveFiller::PerformVF()* |
671 | 2 | Access to the pairs of interfered shapes <i>(nVi, nFj)k, k=0, 1…nk,</i> where *nVi* is DS index of the vertex *Vi*, *nFj* is DS index of the edge *Fj* and *nk* is the number of pairs. | *BOPDS_Iterator* |
672 | 3 | Compute interference See @ref specification__boolean_3_1_3 "Vertex/Face Interference" | *BOPInt_Context::ComputeVF()* |
673 | 4 | Append Vertex/Face interferences in the DS | *BOPDS_DS::AddInterf()* |
674 | 5 | Repeat steps 2-4 for each new vertex *VNXi (i=1, 2…,NbVNX),* where *NbVNX* is the number of vertices. | *BOPAlgo_PaveFiller::TreatVerticesEE()* |
676 @subsection specification__boolean_5_7 Compute Edge/Face Interferences
677 The input data for this step is the DS after computing Vertex/Face Interferences.
679 | No | Contents | Implementation |
680 | :---- | :---- | :---- |
681 | 1 | Initialize array of Edge/Face interferences | *BOPAlgo_PaveFiller::PerformEF()* |
682 | 2 | Access to the pairs of interfered shapes <i>(nEi, nFj)k, k=0, 1…nk,</i> where *nEi* is DS index of edge *Ei*, *nFj* is DS index of face *Fj* and *nk* is the number of pairs. | *BOPDS_Iterator* |
683 | 3 | Initialize pave blocks for the edges involved in the interference, if it is necessary. | *BOPDS_DS::ChangePaveBlocks()* |
684 | 4 | Access to the pave blocks of interfered edge <i>(PBi1, PBi2…PBiNi)</i> for edge *Ei* | *BOPAlgo_PaveFiller::PerformEF()* |
685 | 5 | Compute shrunk data for pave blocks (in terms of @ref specification__boolean_4_4 "Pave, PaveBlock and CommonBlock") if it is necessary. | *BOPAlgo_PaveFiller::FillShrunkData()* |
686 | 6 | Compute Edge/Face interference for pave block *PBix*, and face *nFj*. The result of the computation is a set of objects of type *IntTools_CommonPart* | *IntTools_EdgeFace* |
687 | 7.1 | For each *CommonPart* of type *VERTEX:* Create new vertices *VNi (i=1, 2…,NbVN),* where *NbVN* is the number of new vertices. Merge vertices *VNi* as follows: a) create new object *PFn* of type *BOPAlgo_PaveFiller* with its own DS; b) use new vertices *VNi (i=1, 2…,NbVN), NbVN* as arguments (in terms of *TopoDs_Shape*) of *PFn*; c) invoke method *Perform()* for *PFn*. The resulting vertices *VNXi (i=1, 2…,NbVNX)*, where *NbVNX* is the number of vertices, are obtained via mapping between *VNi* and the results of *PVn*. | *BOPTools_Tools::MakeNewVertex()* and *BOPAlgo_PaveFiller::PerformVertices1()* |
688 | 7.2 | For each *CommonPart* of type *EDGE:* Create common blocks <i>(CBc. C=0, 1…nCs)</i> from pave blocks that lie on the faces. Attach the common blocks to the pave blocks. | *BOPAlgo_Tools::PerformCommonBlocks()* |
689 | 8 | Post-processing. Append the paves of *VNXi* into the corresponding pave blocks in terms of @ref specification__boolean_4_4 "Pave, PaveBlock and CommonBlock". | *BOPDS_PaveBlock:: AppendExtPave()* |
690 | 9 | Split pave blocks and common blocks *CBc* by the paves. | *BOPAlgo_PaveFiller::PerformVertices1()*, *BOPDS_DS:: UpdatePaveBlock()* and *BOPDS_DS:: UpdateCommonBlock()* |
691 | 10 | Append Edge/Face interferences in the DS | *BOPDS_DS::AddInterf()* |
692 | 11 | Update *FaceInfo* for all faces having EF common parts. | *BOPDS_DS:: UpdateFaceInfoIn()* |
695 @subsection specification__boolean_5_8 Build Split Edges
697 The input data for this step is the DS after computing Edge/Face Interferences.
699 For each pave block *PB* take the following steps:
701 | No | Contents | Implementation |
702 | :--- | :--- | :--- |
703 | 1 | Get the real pave block *PBR*, which is equal to *PB* if *PB* is not a common block and to *PB<sub>1</sub>* if *PB* is a common block. *PB<sub>1</sub>* is the first pave block in the pave blocks list of the common block. See @ref specification__boolean_4_4 "Pave, PaveBlock and CommonBlock". | *BOPAlgo_PaveFiller::MakeSplitEdges()* |
704 | 2 | Build the split edge *Esp* using the information from *DS* and *PBR*. | *BOPTools_Tools::MakeSplitEdge()* |
705 | 3 | Compute *BOPDS_ShapeInfo* contents for Esp | *BOPAlgo_PaveFiller::MakeSplitEdges()* |
706 | 4 | Append *BOPDS_ShapeInfo* contents to the DS | *BOPDS_DS::Append()* |
708 @subsection specification__boolean_5_9 Compute Face/Face Interferences
710 The input data for this step is DS after building Split Edges.
712 | No | Contents | Implementation |
713 | :--- | :--- | :--- |
714 | 1 | Initialize array of Face/Face interferences | *BOPAlgo_PaveFiller::PerformFF()* |
715 | 2 | Access to the pairs of interfered shapes <i>(nFi, nFj)k, k=0, 1…nk,</i> where *nFi* is DS index of edge *Fi*, *nFj* is DS index of face *Fj* and *nk* is the number of pairs. | *BOPDS_Iterator* |
716 | 3 | Compute Face/Face interference | *IntTools_FaceFace* |
717 | 4 | Append Face/Face interferences in the DS. | *BOPDS_DS::AddInterf()* |
719 @subsection specification__boolean_5_10 Build Section Edges
721 The input data for this step is the DS after computing Face/Face interferences.
723 | No | Contents | Implementation |
724 | :---- | :---- | :---- |
725 | 1 | For each Face/Face interference *nFi, nFj*, retrieve @ref specification__boolean_4_6 "FaceInfo". Create draft vertices from intersection points *VPk (k=1, 2…, NbVP)*, where *NbVP* is the number of new vertices, and the draft vertex *VPk* is created from an intersection point if *VPk ≠ Vm (m = 0, 1, 2… NbVm)*, where *Vm* is an existing vertex for the faces *nFi* and *nF,j* (*On* or *In* in terms of *TopoDs_Shape*), *NbVm* is the number of vertices existing on faces *nFi* and *nF,j* and ≠ -- means non-coincidence in terms of @ref specification__boolean_3_1_1 "Vertex/Vertex interference". | *BOPAlgo_PaveFiller::MakeBlocks()* |
726 | 2 | For each intersection curve *Cijk* | |
727 | 2.1 | Create paves PVc for the curve using existing vertices, i.e. vertices On or In (in terms of *FaceInfo*) for faces *nFi* and *nFj*. Append the paves *PVc* | *BOPAlgo_PaveFiller::PutPaveOnCurve()* and *BOPDS_PaveBlock::AppendExtPave()* |
728 | 2.2 | Create technological vertices *Vt*, which are the bounding points of an intersection curve (with the value of tolerance *Tol(Cijk)*). Each vertex *Vt* with parameter *Tt* on curve *Cijk* forms pave *PVt* on curve *Cijk*. Append technological paves. | *BOPAlgo_PaveFiller::PutBoundPaveOnCurve()* |
729 | 2.3 | Create pave blocks *PBk* for the curve using paves <i>(k=1, 2…, NbPB)</i>, where *NbPB* is the number of pave blocks | *BOPAlgo_PaveFiller::MakeBlocks()* |
730 | 2.4 | Build draft section edges *ESk* using the pave blocks <i>(k=1, 2…, NbES)</i>, where *NbES* is the number of draft section edges The draft section edge is created from a pave block *PBk* if *PBk* has state *In* or *On* for both faces *nFi* and *nF,j* and *PBk ≠ PBm (m=0, 1, 2… NbPBm)*, where *PBm* is an existing pave block for faces *nFi* and *nF,j* (*On* or *In* in terms of *FaceInfo*), *NbVm* is the number of existing pave blocks for faces *nFi* and *nF,j* and ≠ -- means non-coincidence (in terms of @ref specification__boolean_3_1_3 "Vertex/Face interference"). | *BOPTools_Tools::MakeEdge()* |
731 | 3 | Intersect the draft vertices *VPk (k=1, 2…, NbVP)* and the draft section edges *ESk (k=1, 2…, NbES)*. For this: a) create new object *PFn* of type *BOPAlgo_PaveFiller* with its own DS; b) use vertices *VPk* and edges *ESk* as arguments (in terms of @ref specification__boolean_4_1 "Arguments") of *PFn*; c) invoke method *Perform()* for *PFn*. Resulting vertices *VPXk (k=1, 2… NbVPX)* and edges *ESXk (k=1, 2… NbESX)* are obtained via mapping between *VPk, ESk* and the results of *PVn*. | *BOPAlgo_PaveFiller::PostTreatFF()* |
732 | 4 | Update face info (sections about pave blocks and vertices) | *BOPAlgo_PaveFiller::PerformFF()* |
734 @subsection specification__boolean_5_11 Build P-Curves
735 The input data for this step is the DS after building section edges.
737 | No | Contents | Implementation |
738 | :---- | :---- | :---- |
739 | 1 | For each Face/Face interference *nFi* and *nFj* build p-Curves on *nFi* and *nFj* for each section edge *ESXk*. | *BOPAlgo_PaveFiller::MakePCurves()* |
740 | 2 | For each pave block that is common for faces *nFi* and *nFj* build p-Curves on *nFi* and *nFj*. | *BOPAlgo_PaveFiller::MakePCurves()* |
742 @subsection specification__boolean_5_12 Process Degenerated Edges
743 The input data for this step is the DS after building P-curves.
745 | No | Contents | Implementation |
746 | :---- | :---- | :---- |
747 | | For each degenerated edge *ED* having vertex *VD* | BOPAlgo_PaveFiller::ProcessDE() |
748 | 1 | Find pave blocks *PBi (i=1,2… NbPB)*, where *NbPB* is the number of pave blocks, that go through vertex *VD*. | *BOPAlgo_PaveFiller::FindPaveBlocks()* |
749 | 2 | Compute paves for the degenerated edge *ED* using a 2D curve of *ED* and a 2D curve of *PBi*. Form pave blocks *PBDi (i=1,2… NbPBD)*, where *NbPBD* is the number of the pave blocks for the degenerated edge *ED* | *BOPAlgo_PaveFiller::FillPaves()* |
750 | 3 | Build split edges *ESDi (i=1,2…NbESD)*, where *ESD* is the number of split edges, using the pave blocks *PBDi* | *BOPAlgo_PaveFiller:: MakeSplitEdge()* |
752 @section specification__boolean_6 General description of the Building Part
754 Building Part (BP) is used to
755 * Build the result of the operation
756 * Provide history information (in terms of <i>\::Generated(), \::Modified()</i> and <i>\::IsDeleted()</i>)
757 BP uses the DS prepared by *BOPAlgo_PaveFiller* described at chapter 5 as input data.
758 BP is implemented in the following classes:
759 * *BOPAlgo_Builder* -- for the General Fuse operator (GFA).
760 * *BOPAlgo_BOP* -- for the Boolean Operation operator (BOA).
761 * *BOPAlgo_Section* -- for the Section operator (SA).
762 * *BOPAlgo_MakerVolume* -- for the Volume Maker operator.
763 * *BOPAlgo_Splitter* -- for the Splitter operator.
764 * *BOPAlgo_CellsBuilder* -- for the Cells Builder operator.
766 @figure{/specification/boolean_operations/images/operations_image020.png,"Diagram for BP classes",300}
768 The class *BOPAlgo_BuilderShape* provides the interface for algorithms that have:
769 * A Shape as the result;
770 * History information (in terms of <i>\::Generated(), \::Modified()</i> and <i>\::IsDeleted()).</i>
772 @section specification__boolean_7 General Fuse Algorithm
773 @subsection specification__boolean_7_1 Arguments
774 The arguments of the algorithm are shapes (in terms of *TopoDS_Shape*). The main requirements for the arguments are described in @ref specification__boolean_4 "Data Structure" chapter.
776 @subsection specification__boolean_7_2 Results
778 During the operation argument *Si* can be split into several parts *Si1, Si2… Si1NbSp*, where *NbSp* is the number of parts. The set <i>(Si1, Si2… Si1NbSp)</i> is an image of argument *Si*.
779 * The result of the General Fuse operation is a compound. Each sub-shape of the compound corresponds to the certain argument shape S1, S2…Sn and has shared sub-shapes in accordance with interferences between the arguments.
780 * For the arguments of the type EDGE, FACE, SOLID the result contains split parts of the argument.
781 * For the arguments of the type WIRE, SHELL, COMPSOLID, COMPOUND the result contains the image of the shape of the corresponding type (i.e. WIRE, SHELL, COMPSOLID or COMPOUND).
782 The types of resulting shapes depend on the type of the corresponding argument participating in the operation. See the table below:
784 | No | Type of argument | Type of resulting shape | Comments |
785 | :--- | :---- | :--- | :--- |
786 | 1 | COMPOUND | COMPOUND | The resulting COMPOUND is built from images of sub-shapes of type COMPOUND COMPSOLID, SHELL, WIRE and VERTEX. Sets of split sub-shapes of type SOLID, FACE, EDGE. |
787 | 2 | COMPSOLID | COMPSOLID | The resulting COMPSOLID is built from split SOLIDs. |
788 | 3 | SOLID | Set of split SOLIDs | |
789 | 4 | SHELL | SHELL | The resulting SHELL is built from split FACEs |
790 | 5 | FACE | Set of split FACEs | |
791 | 6 | WIRE | WIRE | The resulting WIRE is built from split EDGEs |
792 | 7 | EDGE | Set of split EDGEs | |
793 | 8 | VERTEX | VERTEX | |
795 @subsection specification__boolean_7_3a Options
797 The General Fuse algorithm has a set of options, which allow speeding-up the operation and improving the quality of the result:
798 * Parallel processing option allows running the algorithm in parallel mode;
799 * Fuzzy option allows setting the additional tolerance for the operation;
800 * Safe input shapes option allows preventing modification of the input shapes;
801 * Gluing option allows speeding-up the intersection of the arguments;
802 * Possibility to disable the check for the inverted solids among input shapes;
803 * Usage of Oriented Bounding Boxes in the operation;
806 For more detailed information on these options, see the @ref specification__boolean_11a "Advanced options" section.
808 @subsection specification__boolean_7_3b Usage
810 The following example illustrates how to use the GF algorithm:
812 #### Usage of the GF algorithm on C++ level
815 BOPAlgo_Builder aBuilder;
817 TopTools_ListOfShape aLSObjects = …; // Objects
818 aBuilder.SetArguments(aLSObjects);
820 // Setting options for GF
822 // Set parallel processing mode (default is false)
823 Standard_Boolean bRunParallel = Standard_True;
824 aBuilder.SetRunParallel(bRunParallel);
826 // Set Fuzzy value (default is Precision::Confusion())
827 Standard_Real aFuzzyValue = 1.e-5;
828 aBuilder.SetFuzzyValue(aFuzzyValue);
830 // Set safe processing mode (default is false)
831 Standard_Boolean bSafeMode = Standard_True;
832 aBuilder.SetNonDestructive(bSafeMode);
834 // Set Gluing mode for coinciding arguments (default is off)
835 BOPAlgo_GlueEnum aGlue = BOPAlgo_GlueShift;
836 aBuilder.SetGlue(aGlue);
838 // Disabling/Enabling the check for inverted solids (default is true)
839 Standard Boolean bCheckInverted = Standard_False;
840 aBuilder.SetCheckInverted(bCheckInverted);
842 // Set OBB usage (default is false)
843 Standard_Boolean bUseOBB = Standard_True;
844 aBuilder.SetUseOBB(buseobb);
846 // Perform the operation
849 // Check for the errors
850 if (aBuilder.HasErrors())
855 // Check for the warnings
856 if (aBuilder.HasWarnings())
858 // treatment of the warnings
862 // result of the operation
863 const TopoDS_Shape& aResult = aBuilder.Shape();
866 #### Usage of the GF algorithm on Tcl level
869 # prepare the arguments
871 box b2 3 4 5 10 10 10
872 box b3 5 6 7 10 10 10
874 # clear inner contents
875 bclearobjects; bcleartools;
880 # setting options for GF
882 # set parallel processing mode (default is 0)
888 # set safe processing mode (default is 0)
891 # set gluing mode (default is 0)
894 # set check for inverted (default is 1)
897 # set obb usage (default is 0)
900 # perform intersection
903 # perform GF operation
907 @subsection specification__boolean_7_3 Examples
909 Have a look at the examples to better understand the definitions.
911 @subsubsection specification__boolean_7_3_1 Case 1: Three edges intersecting at a point
913 Let us consider three edges: *E1, E2* and *E3* that intersect in one 3D point.
915 @figure{/specification/boolean_operations/images/operations_image021.svg,"Three Intersecting Edges",420}
917 The result of the GFA operation is a compound containing 6 new edges: *E11, E12, E21, E22, E31*, and *E32*. These edges have one shared vertex *Vn1*.
920 * The argument edge *E1* has resulting split edges *E11* and *E12* (image of *E1*).
921 * The argument edge *E2* has resulting split edges *E21* and *E22* (image of *E2*).
922 * The argument edge *E3* has resulting split edges *E31* and *E32* (image of *E3*).
924 @subsubsection specification__boolean_7_3_2 Case 2: Two wires and an edge
926 Let us consider two wires *W1 (Ew11, Ew12, Ew13)* and *W2 (Ew21, Ew22, Ew23)* and edge *E1*.
928 @figure{/specification/boolean_operations/images/operations_image022.svg,"Two wires and an edge",420}
930 The result of the GF operation is a compound consisting of 2 wires: *Wn1 (Ew11, En1, En2, En3, Ew13)* and *Wn2 (Ew21, En2, En3, En4, Ew23)* and two edges: *E11* and *E12*.
933 * The argument *W1* has image *Wn1*.
934 * The argument *W2* has image *Wn2*.
935 * The argument edge *E1* has split edges *E11* and *E12*. (image of *E1*).
936 The edges *En1, En2, En3, En4* and vertex *Vn1* are new shapes created during the operation. Edge *Ew12* has split edges *En1, En2* and *En3* and edge *Ew22* has split edges *En2, En3* and *En4*.
938 @subsubsection specification__boolean_7_3_3 Case 3: An edge intersecting with a face
940 Let us consider edge *E1* and face *F2*:
942 @figure{/specification/boolean_operations/images/operations_image023.svg,"An edge intersecting with a face",420}
944 The result of the GF operation is a compound consisting of 3 shapes:
945 * Split edge parts *E11* and *E12* (image of *E1*).
946 * New face *F21* with internal edge *E12* (image of *F2*).
948 @subsubsection specification__boolean_7_3_4 Case 4: An edge lying on a face
950 Let us consider edge *E1* and face *F2*:
952 @figure{/specification/boolean_operations/images/operations_image024.svg,"An edge lying on a face",420}
954 The result of the GF operation is a compound consisting of 5 shapes:
955 * Split edge parts *E11, E12* and *E13* (image of *E1*).
956 * Split face parts *F21* and *F22* (image of *F2*).
959 @subsubsection specification__boolean_7_3_5 Case 5: An edge and a shell
961 Let us consider edge *E1* and shell *Sh2* that consists of 2 faces: *F21* and *F22*
963 @figure{/specification/boolean_operations/images/operations_image025.svg,"An edge and a shell",488}
965 The result of the GF operation is a compound consisting of 5 shapes:
966 * Split edge parts *E11, E12 , E13* and *E14* (image of *E1*).
967 * Image shell *Sh21* (that contains split face parts *F211, F212, F221* and *F222*).
969 @subsubsection specification__boolean_7_3_6 Case 6: A wire and a shell
971 Let us consider wire *W1 (E1, E2, E3, E4)* and shell *Sh2 (F21, F22)*.
972 @figure{/specification/boolean_operations/images/operations_image026.svg,"A wire and a shell",427}
974 The result of the GF operation is a compound consisting of 2 shapes:
976 * Image wire *W11* that consists of split edge parts from wire *W1: E11, E12, E13* and *E14*.
977 * Image shell *Sh21* that contains split face parts: *F211, F212, F213, F221, F222* and *F223*.
979 @subsubsection specification__boolean_7_3_7 Case 7: Three faces
981 Let us consider 3 faces: *F1, F2* and *F3*. @figure{/specification/boolean_operations/images/operations_image027.png,"Three faces",420}
983 The result of the GF operation is a compound consisting of 7 shapes:
984 * Split face parts: *Fn1, Fn2, Fn3, Fn4, Fn5, Fn6* and *Fn7*.
986 @subsubsection specification__boolean_7_3_8 Case 8: A face and a shell
988 Let us consider shell *Sh1 (F11, F12, F13)* and face *F2*.
989 @figure{/specification/boolean_operations/images/operations_image028.png,"A face and a shell",420}
991 The result of the GF operation is a compound consisting of 4 shapes:
992 * Image shell *Sh11* that consists of split face parts from shell *Sh1: Fn1, Fn2, Fn3, Fn4, Fn5* and *Fn6*.
993 * Split parts of face *F2: Fn3, Fn6* and *Fn7*.
995 @subsubsection specification__boolean_7_3_9 Case 9: A shell and a solid
997 Let us consider shell *Sh1 (F11, F12…F16)* and solid *So2*. @figure{/specification/boolean_operations/images/operations_image029.png,"A shell and a solid: arguments",220}
999 The result of the GF operation is a compound consisting of 2 shapes:
1000 * Image shell *Sh11* consisting of split face parts of *Sh1: Fn1, Fn2 ... Fn8.*
1001 * Solid *So21* with internal shell. (image of *So2*).
1002 @figure{/specification/boolean_operations/images/operations_image030.png,"A shell and a solid: results",420}
1004 @subsubsection specification__boolean_7_3_10 Case 10: A compound and a solid
1006 Let us consider compound *Cm1* consisting of 2 solids *So11* and *So12*) and solid *So2*.
1007 @figure{/specification/boolean_operations/images/operations_image031.png,"A compound and a solid: arguments",220}
1009 The result of the GF operation is a compound consisting of 4 shapes:
1010 * Image compound *Cm11* consisting of split solid parts from *So11* and *So12 (Sn1, Sn2, Sn3, Sn4)*.
1011 * Split parts of solid *So2 (Sn2, Sn3, Sn5)*.
1013 @figure{/specification/boolean_operations/images/operations_image032.png,"A compound and a solid: results",420}
1015 @subsection specification__boolean_7_4 Class BOPAlgo_Builder
1017 GFA is implemented in the class *BOPAlgo_Builder*.
1019 @subsubsection specification__boolean_7_4_1 Fields
1021 The main fields of the class are described in the Table:
1025 | *myPaveFiller* | Pointer to the *BOPAlgo_PaveFiller* object |
1026 | *myDS* | Pointer to the *BOPDS_DS* object |
1027 | *myContext* | Pointer to the intersection Context |
1028 | *myImages* | The Map between the source shape and its images |
1029 | *myShapesSD* | The Map between the source shape (or split part of source shape) and the shape (or part of shape) that will be used in result due to same domain property. |
1031 @subsubsection specification__boolean_7_4_2 Initialization
1033 The input data for this step is a *BOPAlgo_PaveFiller* object (in terms of @ref specification__boolean_5 "Intersection") at the state after @ref specification__boolean_5_12 "Processing of degenerated edges" with the corresponding DS.
1035 | No | Contents | Implementation |
1036 | :---- | :---- | :---- |
1037 | 1 | Check the readiness of the DS and *BOPAlgo_PaveFiller*. | *BOPAlgo_Builder::CheckData()* |
1038 | 2 | Build an empty result of type Compound. | *BOPAlgo_Builder::Prepare()* |
1040 @subsubsection specification__boolean_7_4_3 Build Images for Vertices
1042 The input data for this step is *BOPAlgo_Builder* object after Initialization.
1044 | No | Contents | Implementation |
1045 | :--- | :--- | :--- |
1046 | 1 | Fill *myShapesSD* by SD vertices using the information from the DS. | *BOPAlgo_Builder::FillImagesVertices()* |
1048 @subsubsection specification__boolean_7_4_4 Build Result of Type Vertex
1050 The input data for this step is *BOPAlgo_Builder* object after building images for vertices and *Type*, which is the shape type (*TopAbs_VERTEX*).
1052 | No | Contents | Implementation |
1053 | :--- | :--- | :----- |
1054 | 1 | For the arguments of type *Type*. If there is an image for the argument: add the image to the result. If there is no image for the argument: add the argument to the result. | *BOPAlgo_Builder::BuildResult()* |
1056 @subsubsection specification__boolean_7_4_5 Build Images for Edges
1058 The input data for this step is *BOPAlgo_Builder object* after building result of type vertex.
1060 | No | Contents | Implementation |
1061 | :---- | :---- | :----- |
1062 | 1 | For all pave blocks in the DS. Fill *myImages* for the original edge *E* by split edges *ESPi* from pave blocks. In case of common blocks on edges, use edge *ESPSDj* that corresponds to the leading pave block and fill *myShapesSD* by the pairs *ESPi/ESPSDj*. | *BOPAlgo_Builder::FillImagesEdges()* |
1064 @subsubsection specification__boolean_7_4_6 Build Result of Type Edge
1066 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex", but for the type *Edge*.
1068 @subsubsection specification__boolean_7_4_7 Build Images for Wires
1070 The input data for this step is:
1071 * *BOPAlgo_Builder* object after building result of type *Edge*;
1072 * Original Shape -- Wire
1073 * *Type* -- the shape type <i>(TopAbs_WIRE).</i>
1075 | No | Contents | Implementation |
1076 | :---- | :---- | :----- |
1077 | 1 | For all arguments of the type *Type*. Create a container C of the type *Type*. | *BOPAlgo_Builder::FillImagesContainers()* |
1078 | 2 | Add to C the images or non-split parts of the *Original Shape*, taking into account its orientation. | *BOPAlgo_Builder::FillImagesContainers()* *BOPTools_Tools::IsSplitToReverse()* |
1079 | 3 | Fill *myImages* for the *Original Shape* by the information above. | *BOPAlgo_Builder::FillImagesContainers()* |
1081 @subsubsection specification__boolean_7_4_8 Build Result of Type Wire
1083 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex" but for the type *Wire*.
1085 @subsubsection specification__boolean_7_4_9 Build Images for Faces
1087 The input data for this step is *BOPAlgo_Builder* object after building result of type *Wire*.
1089 | No | Contents | Implementation |
1090 | :--- | :--- | :--- |
1091 | 1 | Build Split Faces for all interfered DS shapes *Fi* of type *FACE*. | |
1092 | 1.1 | Collect all edges or their images of *Fi(ESPij)*. | *BOPAlgo_Builder::BuildSplitFaces()* |
1093 | 1.2 | Impart to ESPij the orientation to be coherent with the original one. | *BOPAlgo_Builder::BuildSplitFaces()* |
1094 | 1.3 | Collect all section edges *SEk* for *Fi*. | *BOPAlgo_Builder::BuildSplitFaces()* |
1095 | 1.4 | Build split faces for *Fi (Fi1, Fi2…FiNbSp)*, where *NbSp* is the number of split parts (see @ref specification__boolean_7_2 "Building faces from a set of edges" for more details). | *BOPAlgo_BuilderFace* |
1096 | 1.5 | Impart to <i>(Fi1, Fi2…FiNbSp)</i> the orientation coherent with the original face *Fi*. | *BOPAlgo_Builder::BuildSplitFaces()* |
1097 | 1.6 | Fill the map mySplits with *Fi/(Fi1, Fi2…FiNbSp)* | *BOPAlgo_Builder::BuildSplitFaces()* |
1098 | 2 | Fill Same Domain faces | *BOPAlgo_Builder::FillSameDomainFaces* |
1099 | 2.1 | Find and collect in the contents of *mySplits* the pairs of same domain split faces <i>(Fij, Fkl)m</i>, where *m* is the number of pairs. | *BOPAlgo_Builder::FillSameDomainFaces* *BOPTools_Tools::AreFacesSameDomain()* |
1100 | 2.2 | Compute the connexity chains 1) of same domain faces <i>(F1C, F2C… FnC)k, C=0, 1…nCs,</i> where *nCs* is the number of connexity chains. | *BOPAlgo_Builder::FillSameDomainFaces()* |
1101 | 2.3 | Fill *myShapesSD* using the chains <i>(F1C, F2C… FnC)k</i> | *BOPAlgo_Builder::FillSameDomainFaces()* |
1102 | 2.4 | Add internal vertices to split faces. | *BOPAlgo_Builder::FillSameDomainFaces()* |
1103 | 2.5 | Fill *myImages* using *myShapesSD* and *mySplits*. | *BOPAlgo_Builder::FillSameDomainFaces()* |
1106 The example of chains of same domain faces is given in the image:
1108 @figure{/specification/boolean_operations/images/operations_image033.svg,"Chains of same domain faces",420}
1110 * The pairs of same domain faces are: <i>(F11, F21), (F22, F31), (F41, F51) , (F41, F6)</i> and <i>(F51, F6)</i>.
1111 * The pairs produce the three chains: <i>(F11, F21), (F22, F31)</i> and <i>(F41, F51, F6)</i>.
1113 @subsubsection specification__boolean_7_4_10 Build Result of Type Face
1114 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex" but for the type *Face*.
1116 @subsubsection specification__boolean_7_4_11 Build Images for Shells
1117 The input data for this step is:
1118 * *BOPAlgo_Builder* object after building result of type face;
1119 * *Original Shape* -- a Shell;
1120 * *Type* -- the type of the shape <i>(TopAbs_SHELL)</i>.
1122 The procedure is the same as for building images for wires.
1124 @subsubsection specification__boolean_7_4_12 Build Result of Type Shell
1125 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex" but for the type *Shell*.
1127 @subsubsection specification__boolean_7_4_13 Build Images for Solids
1129 The input data for this step is *BOPAlgo_Builder* object after building result of type *Shell*.
1131 The following procedure is executed for all interfered DS shapes *Si* of type *SOLID*.
1133 | No | Contents | Implementation |
1134 | :--- | :--- | :--- |
1135 | 1 | Collect all images or non-split parts for all faces <i>(FSPij)</i> that have 3D state *In Si*. | *BOPAlgo_Builder::FillIn3DParts ()* |
1136 | 2 | Collect all images or non-split parts for all faces of *Si* | *BOPAlgo_Builder::BuildSplitSolids()* |
1137 | 3 | Build split solids for *Si -> (Si1, Si2…SiNbSp)*, where *NbSp* is the number of split parts (see @ref specification__boolean_7_2 "Building faces from a set of edges" for more details) | *BOPAlgo_BuilderSolid* |
1138 | 4 | Fill the map Same Domain solids *myShapesSD* | *BOPAlgo_Builder::BuildSplitSolids()* |
1139 | 5 | Fill the map *myImages* | *BOPAlgo_Builder::BuildSplitSolids()* |
1140 | 6 | Add internal vertices to split solids | *BOPAlgo_Builder::FillInternalShapes()* |
1142 @subsubsection specification__boolean_7_4_14 Build Result of Type Solid
1143 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex", but for the type Solid.
1145 @subsubsection specification__boolean_7_4_15 Build Images for Type CompSolid
1147 The input data for this step is:
1148 * *BOPAlgo_Builder* object after building result of type solid;
1149 * *Original Shape* -- a Compsolid;
1150 * *Type* -- the type of the shape <i>(TopAbs_COMPSOLID)</i>.
1152 The procedure is the same as for building images for wires.
1154 @subsubsection specification__boolean_7_4_16 Build Result of Type Compsolid
1155 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex", but for the type Compsolid.
1157 @subsubsection specification__boolean_7_4_17 Build Images for Compounds
1158 The input data for this step is as follows:
1159 * *BOPAlgo_Builder* object after building results of type *compsolid*;
1160 * *Original Shape* -- a Compound;
1161 * *Type* -- the type of the shape <i>(TopAbs_COMPOUND)</i>.
1163 The procedure is the same as for building images for wires.
1165 @subsubsection specification__boolean_7_4_18 Build Result of Type Compound
1167 This step is the same as @ref specification__boolean_7_4_4 "Building Result of Type Vertex", but for the type Compound.
1169 @subsubsection specification__boolean_7_4_19 Post-Processing
1170 The purpose of the step is to correct tolerances of the result to provide its validity in terms of *BRepCheck_Analyzer.*
1172 The input data for this step is a *BOPAlgo_Builder* object after building result of type compound.
1174 | No | Contents | Implementation |
1175 | :---- | :---- | :----- |
1176 | 1 | Correct tolerances of vertices on curves | *BOPTools_Tools::CorrectPointOnCurve()* |
1177 | 2 | Correct tolerances of edges on faces | *BOPTools_Tools::CorrectCurveOnSurface()* |
1180 @section specification__boolean_8 Splitter Algorithm
1182 The Splitter algorithm allows splitting a group of arbitrary shapes by another group of arbitrary shapes.<br>
1183 It is based on the General Fuse algorithm, thus all options of the General Fuse (see @ref specification__boolean_7_3a "GF Options") are also available in this algorithm.
1185 @subsection specification__boolean_8_1 Arguments
1187 * The arguments of the Splitter algorithm are divided into two groups - *Objects* (shapes that will be split) and *Tools* (shapes, by which the *Objects* will be split);
1188 * The requirements for the arguments (both for *Objects* and *Tools*) are the same as for the General Fuse algorithm - there can be any number of arguments of any type in each group, but each argument should be valid and not self-interfered.
1190 @subsection specification__boolean_8_2 Results
1192 * The result of Splitter algorithm contains only the split parts of the shapes included into the group of *Objects*;
1193 * The split parts of the shapes included only into the group of *Tools* are excluded from the result;
1194 * If there are no shapes in the group of *Tools* the result of the operation will be equivalent to the result of General Fuse operation;
1195 * The shapes can be split by other shapes from the same group (if these shapes are interfering).
1197 @subsection specification__boolean_8_3 Usage
1199 @subsubsection specification__boolean_8_3_1 API
1201 On the low level the Splitter algorithm is implemented in class *BOPAlgo_Splitter*. The usage of this algorithm looks as follows:
1203 BOPAlgo_Splitter aSplitter;
1204 // Setting arguments and tools
1205 TopTools_ListOfShape aLSObjects = …; // Objects
1206 TopTools_ListOfShape aLSTools = …; // Tools
1207 aSplitter.SetArguments(aLSObjects);
1208 aSplitter.SetTools(aLSTools);
1210 // Set options for the algorithm
1211 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
1214 // Perform the operation
1215 aSplitter.Perform();
1216 if (aSplitter.HasErrors()) { //check error status
1220 const TopoDS_Shape& aResult = aSplitter.Shape(); // result of the operation
1223 @subsubsection specification__boolean_8_3_2 DRAW
1225 The command *bsplit* implements the Splitter algorithm in DRAW. Similarly to the *bbuild* command for the General Fuse algorithm, the *bsplit* command should be used after the Pave Filler is filled.
1227 # s1 s2 s3 - objects
1231 baddobjects s1 s2 s3
1237 @subsection specification__boolean_8_4 Examples
1239 @subsubsection specification__boolean_8_4_1 Example 1
1241 Splitting a face by the set of edges:
1244 # draw script for reproducing
1249 cylinder cyl 0 0 0 0 0 1 10
1250 mkface f cyl 0 2*pi -$height $height
1258 set ustep [expr $pi2/$nb_uedges]
1259 for {set i 0} {$i <= $pi2} {set i [expr $i + $ustep]} {
1266 set vstep [expr 2*$height/$nb_vedges]
1267 for {set i -20} {$i <= 20} {set i [expr $i + $vstep]} {
1278 <table align="center">
1280 <td>@figure{/specification/boolean_operations/images/bsplit_image001.png,"Arguments",160}</td>
1281 <td>@figure{/specification/boolean_operations/images/bsplit_image002.png,"Result",160}</td>
1285 @subsubsection specification__boolean_8_4_2 Example 2
1287 Splitting a plate by the set of cylinders:
1290 # draw script for reproducing:
1299 for {set i 0} {$i < 101} {incr i 5} {
1300 for {set j 0} {$j < 101} {incr j 5} {
1302 ttranslate p1 $i $j -5;
1312 <table align="center">
1314 <td>@figure{/specification/boolean_operations/images/bsplit_image003.png,"Arguments",160}</td>
1315 <td>@figure{/specification/boolean_operations/images/bsplit_image004.png,"Result",160}</td>
1319 @subsubsection specification__boolean_8_4_3 Example 3
1321 Splitting shell hull by the planes:
1322 <table align="center">
1324 <td>@figure{/specification/boolean_operations/images/bsplit_image005.png,"Arguments",160}</td>
1325 <td>@figure{/specification/boolean_operations/images/bsplit_image006.png,"Results",160}</td>
1329 @section specification__boolean_9 Boolean Operations Algorithm
1331 @subsection specification__boolean_9_1 Arguments
1333 * The arguments of BOA are shapes in terms of *TopoDS_Shape*. The main requirements for the arguments are described in the @ref specification__boolean_4 "Data Structure"
1334 * There are two groups of arguments in BOA:
1335 * Objects <i>(S1=S11, S12, ...)</i>;
1336 * Tools <i>(S2=S21, S22, ...)</i>.
1337 * The following table contains the values of dimension for different types of arguments:
1339 | No | Type of Argument | Index of Type | Dimension |
1340 | :---- | :---- | :----- | :---- |
1341 | 1 | COMPOUND | 0 | One of 0, 1, 2, 3 |
1342 | 2 | COMPSOLID | 1 | 3 |
1343 | 3 | SOLID | 2 | 3 |
1344 | 4 | SHELL | 3 | 2 |
1345 | 5 | FACE | 4 | 2 |
1346 | 6 | WIRE | 5 | 1 |
1347 | 7 | EDGE | 6 | 1 |
1348 | 8 | VERTEX | 7 | 0 |
1350 * For Boolean operation Fuse all arguments should have equal dimensions.
1351 * For Boolean operation Cut the minimal dimension of *S2* should not be less than the maximal dimension of *S1*.
1352 * For Boolean operation Common the arguments can have any dimension.
1354 @subsection specification__boolean_9_3 Results. General Rules
1356 * The result of the Boolean operation is a compound (if defined). Each sub-shape of the compound has shared sub-shapes in accordance with interferences between the arguments.
1357 * The content of the result depends on the type of the operation (Common, Fuse, Cut12, Cut21) and the dimensions of the arguments.
1358 * The result of the operation Fuse is defined for arguments *S1* and *S2* that have the same dimension value : *Dim(S1)=Dim(S2)*. If the arguments have different dimension values the result of the operation Fuse is not defined. The dimension of the result is equal to the dimension of the arguments. For example, it is impossible to fuse an edge and a face.
1359 * The result of the operation Fuse for arguments *S1* and *S2* contains the parts of arguments that have states **OUT** relative to the opposite arguments.
1360 * The result of the operation Fuse for arguments *S1* and *S2* having dimension value 3 (Solids) is refined by removing all possible internal faces to provide minimal number of solids.
1361 * The result of the operation Common for arguments *S1* and *S2* is defined for all values of the dimensions of the arguments. The result can contain shapes of different dimensions, but the minimal dimension of the result will be equal to the minimal dimension of the arguments. For example, the result of the operation Common between edges cannot be a vertex.
1362 * The result of the operation Common for the arguments *S1* and *S2* contains the parts of the argument that have states **IN** and **ON** relative to the opposite argument.
1363 * The result of the operation Cut is defined for arguments *S1* and *S2* that have values of dimensions *Dim(S2)* that should not be less than *Dim(S1)*. The result can contain shapes of different dimensions, but the minimal dimension of the result will be equal to the minimal dimension of the objects *Dim(S1)*. The result of the operation *Cut12* is not defined for other cases. For example, it is impossible to cut an edge from a solid, because a solid without an edge is not defined.
1364 * The result of the operation *Cut12* for arguments *S1* and *S2* contains the parts of argument *S1* that have state **OUT** relative to the opposite argument *S2*.
1365 * The result of the operation *Cut21* for arguments *S1* and *S2* contains the parts of argument *S2* that have state **OUT** relative to the opposite argument *S1*.
1366 * For the arguments of collection type (WIRE, SHELL, COMPSOLID) the type will be passed in the result. For example, the result of Common operation between Shell and Wire will be a compound containing Wire.
1367 * For the arguments of collection type (WIRE, SHELL, COMPSOLID) containing overlapping parts the overlapping parts passed into result will be repeated for each container from the input shapes containing such parts. The containers completely included in other containers will be avoided in the result.
1368 * For the arguments of collection type (WIRE, SHELL, COMPSOLID) the containers included into result will have the same orientation as the original containers from arguments. In case of duplication its orientation will be defined by the orientation of the first container in arguments. Each container included into result will have coherent orientation of its sub-shapes.
1369 * The result of the operation Fuse for the arguments of collection type (WIRE, SHELL) will consist of the shapes of the same collection type. The overlapping parts (EDGES/FACES) will be shared among containers, but duplicating containers will be avoided in the result. For example, the result of Fuse operation between two fully coinciding wires will be one wire, but the result of Fuse operation between two partially coinciding wires will be two wires sharing coinciding edges.
1370 * The result of the operation Fuse for the arguments of type COMPSOLID will consist of the compound containing COMPSOLIDs created from connexity blocks of fused solids.
1371 * The result of the operation Common for the arguments of collection type (WIRE, SHELL, COMPSOLID) will consist of the unique containers containing the overlapping parts. For example, the result of Common operation between two fully overlapping wires will be one wire containing all splits of edges. The number of wires in the result of Common operation between two partially overlapping wires will be equal to the number of connexity blocks of overlapping edges.
1373 @subsection specification__boolean_9_4 Examples
1375 @subsubsection specification__boolean_9_4_1 Case 1: Two Vertices
1377 Let us consider two interfering vertices *V1* and *V2*:
1379 @figure{/specification/boolean_operations/images/boolean_image001.svg,"",160}
1381 * The result of *Fuse* operation is the compound that contains new vertex *V*.
1383 @figure{/specification/boolean_operations/images/boolean_image002.svg,"",160}
1385 * The result of *Common* operation is a compound containing new vertex *V*.
1387 * The result of *Cut12* operation is an empty compound.
1388 * The result of *Cut21* operation is an empty compound.
1390 @subsubsection specification__boolean_9_4_2 Case 2: A Vertex and an Edge
1392 Let us consider vertex *V1* and the edge *E2*, that intersect in a 3D point:
1394 @figure{/specification/boolean_operations/images/boolean_image004.png,"",230}
1396 * The result of *Fuse* operation is result is not defined because the dimension of the vertex (0) is not equal to the dimension of the edge (1).
1398 * The result of *Common* operation is a compound containing vertex *V<sub>1</sub>* as the argument *V<sub>1</sub>* has a common part with edge *E2*.
1400 @figure{/specification/boolean_operations/images/boolean_image005.png,"",230}
1402 * The result of *Cut12* operation is an empty compound.
1403 * The result of *Cut21* operation is not defined because the dimension of the vertex (0) is less than the dimension of the edge (1).
1405 @subsubsection specification__boolean_9_4_3 Case 3: A Vertex and a Face
1407 Let us consider vertex *V1* and face *F2*, that intersect in a 3D point:
1409 @figure{/specification/boolean_operations/images/boolean_image006.png,"",230}
1411 * The result of *Fuse* operation is not defined because the dimension of the vertex (0) is not equal to the dimension of the face (2).
1413 * The result of *Common* operation is a compound containing vertex *V<sub>1</sub>* as the argument *V<sub>1</sub>* has a common part with face *F2*.
1415 @figure{/specification/boolean_operations/images/boolean_image007.png,"",230}
1417 * The result of *Cut12* operation is an empty compound.
1418 * The result of *Cut21* operation is not defined because the dimension of the vertex (0) is less than the dimension of the face (2).
1420 @subsubsection specification__boolean_9_4_4 Case 4: A Vertex and a Solid
1422 Let us consider vertex *V1* and solid *S2*, that intersect in a 3D point:
1424 @figure{/specification/boolean_operations/images/boolean_image008.png,"",230}
1426 * The result of *Fuse* operation is not defined because the dimension of the vertex (0) is not equal to the dimension of the solid (3).
1428 * The result of *Common* operation is a compound containing vertex *V<sub>1</sub>* as the argument *V<sub>1</sub>* has a common part with solid *S2*.
1430 @figure{/specification/boolean_operations/images/boolean_image009.png,"",230}
1432 * The result of *Cut12* operation is an empty compound.
1433 * The result of *Cut21* operation is not defined because the dimension of the vertex (0) is less than the dimension of the solid (3).
1435 @subsubsection specification__boolean_9_4_5 Case 5: Two edges intersecting at one point
1437 Let us consider edges *E1* and *E2* that intersect in a 3D point:
1439 @figure{/specification/boolean_operations/images/boolean_image010.svg,"",230}
1441 * The result of *Fuse* operation is a compound containing split parts of arguments i.e. 4 new edges *E11, E12, E21*, and *E22*. These edges have one shared vertex *Vn1*.
1443 * argument edge *E1* has resulting split edges *E11* and *E12* (image of *E1*);
1444 * argument edge *E2* has resulting split edges *E21* and *E22* (image of *E2*).
1446 @figure{/specification/boolean_operations/images/boolean_image011.svg,"",230}
1448 * The result of *Common* operation is an empty compound because the dimension (0) of the common part between the edges (vertex) is less than the dimension of the arguments (1).
1450 * The result of *Cut12* operation is a compound containing split parts of the argument *E1*, i.e. 2 new edges *E11* and *E12*. These edges have one shared vertex *Vn1*.
1452 In this case the argument edge *E1* has resulting split edges *E11* and *E12* (image of *E1*).
1454 @figure{/specification/boolean_operations/images/boolean_image012.svg,"",230}
1456 * The result of *Cut21* operation is a compound containing split parts of the argument *E2*, i.e. 2 new edges *E21* and *E12*. These edges have one shared vertex *Vn1*.
1458 In this case the argument edge *E2* has resulting split edges *E21* and *E22* (image of *E2*).
1460 @figure{/specification/boolean_operations/images/boolean_image013.svg,"",70}
1462 @subsubsection specification__boolean_9_4_6 Case 6: Two edges having a common block
1464 Let us consider edges *E1* and *E2* that have a common block:
1466 @figure{/specification/boolean_operations/images/boolean_image014.svg,"",230}
1468 * The result of *Fuse* operation is a compound containing split parts of arguments i.e. 3 new edges *E11*, *E12* and *E22*. These edges have two shared vertices.
1470 * argument edge *E1* has resulting split edges *E11* and *E12* (image of *E1*);
1471 * argument edge *E2* has resulting split edges *E21* and *E22* (image of *E2*);
1472 * edge *E12* is common for the images of *E1* and *E2*.
1474 @figure{/specification/boolean_operations/images/boolean_image015.svg,"",230}
1476 * The result of *Common* operation is a compound containing split parts of arguments i.e. 1 new edge *E12*. In this case edge *E12* is common for the images of *E1* and *E2*.
1477 The common part between the edges (edge) has the same dimension (1) as the dimension of the arguments (1).
1479 @figure{/specification/boolean_operations/images/boolean_image016.svg,"",230}
1481 * The result of *Cut12* operation is a compound containing a split part of argument *E1*, i.e. new edge *E11*.
1483 @figure{/specification/boolean_operations/images/boolean_image017.svg,"",230}
1485 * The result of *Cut21* operation is a compound containing a split part of argument *E2*, i.e. new edge *E22*.
1487 @figure{/specification/boolean_operations/images/boolean_image018.svg,"",230}
1490 @subsubsection specification__boolean_9_4_7 Case 7: An Edge and a Face intersecting at a point
1492 Let us consider edge *E1* and face *F2* that intersect at a 3D point:
1494 @figure{/specification/boolean_operations/images/boolean_image019.png,"",230}
1496 * The result of *Fuse* operation is not defined because the dimension of the edge (1) is not equal to the dimension of the face (2).
1498 * The result of *Common* operation is an empty compound because the dimension (0) of the common part between the edge and face (vertex) is less than the dimension of the arguments (1).
1500 * The result of *Cut12* operation is a compound containing split parts of the argument *E1*, i.e. 2 new edges *E11* and *E12*.
1502 In this case the argument edge *E1* has no common parts with the face *F2* so the whole image of *E1* is in the result.
1504 @figure{/specification/boolean_operations/images/boolean_image020.png,"",230}
1506 * The result of *Cut21* operation is not defined because the dimension of the edge (1) is less than the dimension of the face (2).
1508 @subsubsection specification__boolean_9_4_8 Case 8: A Face and an Edge that have a common block
1510 Let us consider edge *E1* and face *F2* that have a common block:
1512 @figure{/specification/boolean_operations/images/boolean_image021.png,"",230}
1514 * The result of *Fuse* operation is not defined because the dimension of the edge (1) is not equal to the dimension of the face (2).
1516 * The result of *Common* operation is a compound containing a split part of the argument *E1*, i.e. new edge *E12*.
1518 In this case the argument edge *E1* has a common part with face *F2* so the corresponding part of the image of *E1* is in the result. The yellow square is not a part of the result. It only shows the place of *F2*.
1520 @figure{/specification/boolean_operations/images/boolean_image022.png,"",230}
1522 * The result of *Cut12* operation is a compound containing split part of the argument *E1*, i.e. new edge *E11*.
1524 In this case the argument edge *E1* has a common part with face *F2* so the corresponding part is not included into the result. The yellow square is not a part of the result. It only shows the place of F2.
1526 @figure{/specification/boolean_operations/images/boolean_image023.png,"",230}
1528 * The result of *Cut21* operation is not defined because the dimension of the edge (1) is less than the dimension of the face (2).
1530 @subsubsection specification__boolean_9_4_9 Case 9: An Edge and a Solid intersecting at a point
1532 Let us consider edge *E1* and solid *S2* that intersect at a point:
1534 @figure{/specification/boolean_operations/images/boolean_image024.png,"",230}
1536 * The result of *Fuse* operation is not defined because the dimension of the edge (1) is not equal to the dimension of the solid (3).
1538 * The result of *Common* operation is a compound containing a split part of the argument *E1*, i.e. new edge *E12*.
1540 In this case the argument edge *E1* has a common part with solid *S2* so the corresponding part of the image of *E1* is in the result. The yellow square is not a part of the result. It only shows the place of *S2*.
1542 @figure{/specification/boolean_operations/images/boolean_image025.png,"",230}
1544 * The result of *Cut12* operation is a compound containing split part of the argument *E1*, i.e. new edge *E11*.
1546 In this case the argument edge *E1* has a common part with solid *S2* so the corresponding part is not included into the result. The yellow square is not a part of the result. It only shows the place of *S2*.
1548 @figure{/specification/boolean_operations/images/boolean_image071.png,"",230}
1550 * The result of *Cut21* operation is not defined because the dimension of the edge (1) is less than the dimension of the solid (3).
1552 @subsubsection specification__boolean_9_4_10 Case 10: An Edge and a Solid that have a common block
1554 Let us consider edge *E1* and solid *S2* that have a common block:
1556 @figure{/specification/boolean_operations/images/boolean_image072.png,"",230}
1558 * The result of *Fuse* operation is not defined because the dimension of the edge (1) is not equal to the dimension of the solid (3).
1560 * The result of *Common* operation is a compound containing a split part of the argument *E1*, i.e. new edge *E12*.
1562 In this case the argument edge *E1* has a common part with solid *S2* so the corresponding part of the image of *E1* is in the result. The yellow square is not a part of the result. It only shows the place of *S2*.
1564 @figure{/specification/boolean_operations/images/boolean_image073.png,"",230}
1566 * The result of *Cut12* operation is a compound containing split part of the argument *E1*, i.e. new edge *E11*.
1568 In this case the argument edge *E1* has a common part with solid *S2* so the corresponding part is not included into the result. The yellow square is not a part of the result. It only shows the place of *S2*.
1570 @figure{/specification/boolean_operations/images/boolean_image026.png,"",230}
1572 * The result of *Cut21* operation is not defined because the dimension of the edge (1) is less than the dimension of the solid (3).
1574 @subsubsection specification__boolean_9_4_11 Case 11: Two intersecting faces
1576 Let us consider two intersecting faces *F1* and *F2*:
1578 @figure{/specification/boolean_operations/images/boolean_image027.png,"",230}
1580 * The result of *Fuse* operation is a compound containing split parts of arguments i.e. 2 new faces *F11* and *F21*. These faces have one shared edge *En1*.
1582 @figure{/specification/boolean_operations/images/boolean_image028.png,"",230}
1585 * The result of *Common* operation is an empty compound because the dimension (1) of the common part between *F1* and *F2* (edge) is less than the dimension of arguments (2).
1587 * The result of *Cut12* operation is a compound containing split part of the argument *F1*, i.e. new face *F11*.
1589 @figure{/specification/boolean_operations/images/boolean_image029.png,"",230}
1591 * The result of *Cut21* operation is a compound containing split parts of the argument *F2*, i.e. 1 new face *F21*.
1593 @figure{/specification/boolean_operations/images/boolean_image030.png,"",127}
1595 @subsubsection specification__boolean_9_4_12 Case 12: Two faces that have a common part
1597 Let us consider two faces *F1* and *F2* that have a common part:
1599 @figure{/specification/boolean_operations/images/boolean_image031.png,"",230}
1601 * The result of *Fuse* operation is a compound containing split parts of arguments, i.e. 3 new faces: *F11*, *F12* and *F22*. These faces are shared through edges In this case:
1602 * the argument edge *F1* has resulting split faces *F11* and *F12* (image of *F1*)
1603 * the argument face *F2* has resulting split faces *F12* and *F22* (image of *F2*)
1604 * the face *F12* is common for the images of *F1* and *F2*.
1606 @figure{/specification/boolean_operations/images/boolean_image032.png,"",230}
1608 * The result of *Common* operation is a compound containing split parts of arguments i.e. 1 new face *F12*.
1609 In this case: face *F12* is common for the images of *F1* and *F2*.
1610 The common part between the faces (face) has the same dimension (2) as the dimension of the arguments (2).
1613 @figure{/specification/boolean_operations/images/boolean_image033.png,"",230}
1615 * The result of *Cut12* operation is a compound containing split part of the argument *F1*, i.e. new face *F11*.
1617 @figure{/specification/boolean_operations/images/boolean_image034.png,"",230}
1619 * The result of *Cut21* operation is a compound containing split parts of the argument *F2*, i.e. 1 new face *F21*.
1621 @figure{/specification/boolean_operations/images/boolean_image035.png,"",230}
1623 @subsubsection specification__boolean_9_4_13 Case 13: Two faces that have a common edge
1625 Let us consider two faces *F1* and *F2* that have a common edge:
1627 @figure{/specification/boolean_operations/images/boolean_image036.png,"",230}
1629 * The result of *Fuse* operation is a compound containing split parts of arguments, i.e. 2 new faces: *F11* and *F21*. These faces have one shared edge *En1*.
1631 @figure{/specification/boolean_operations/images/boolean_image037.png,"",230}
1633 * The result of *Common* operation is an empty compound because the dimension (1) of the common part between *F1* and *F2* (edge)is less than the dimension of the arguments (2)
1635 * The result of *Cut12* operation is a compound containing split part of the argument *F1*, i.e. new face *F11*. The vertices are shown just to clarify the fact that the edges are spitted.
1637 @figure{/specification/boolean_operations/images/boolean_image038.png,"",230}
1639 * The result of *Cut21* operation is a compound containing split parts of the argument *F2*, i.e. 1 new face *F21*. The vertices are shown just to clarify the fact that the edges are spitted.
1641 @figure{/specification/boolean_operations/images/boolean_image039.png,"",230}
1643 @subsubsection specification__boolean_9_4_14 Case 14: Two faces that have a common vertex
1645 Let us consider two faces *F1* and *F2* that have a common vertex:
1647 @figure{/specification/boolean_operations/images/boolean_image040.png,"",230}
1649 * The result of *Fuse* operation is a compound containing split parts of arguments, i.e. 2 new faces: *F11* and *F21*. These faces have one shared vertex *Vn1*.
1651 @figure{/specification/boolean_operations/images/boolean_image041.png,"",230}
1653 * The result of *Common* operation is an empty compound because the dimension (0) of the common part between *F1* and *F2* (vertex) is less than the dimension of the arguments (2)
1655 * The result of *Cut12* operation is a compound containing split part of the argument *F1*, i.e. new face *F11*.
1657 @figure{/specification/boolean_operations/images/boolean_image042.png,"",230}
1659 * The result of *Cut21* operation is a compound containing split parts of the argument *F2*, i.e. 1 new face *F21*.
1661 @figure{/specification/boolean_operations/images/boolean_image043.png,"",230}
1664 @subsubsection specification__boolean_9_4_15 Case 15: A Face and a Solid that have an intersection curve.
1666 Let us consider face *F1* and solid *S2* that have an intersection curve:
1668 @figure{/specification/boolean_operations/images/boolean_image044.png,"",230}
1670 * The result of *Fuse* operation is not defined because the dimension of the face (2) is not equal to the dimension of the solid (3).
1672 * The result of *Common* operation is a compound containing split part of the argument *F1*. In this case the argument face *F1* has a common part with solid *S2*, so the corresponding part of the image of *F1* is in the result. The yellow contour is not a part of the result. It only shows the place of *S2*.
1674 @figure{/specification/boolean_operations/images/boolean_image045.png,"",230}
1676 * The result of *Cut12* operation is a compound containing split part of the argument *F1*. In this case argument face *F1* has a common part with solid *S2* so the corresponding part is not included into the result. The yellow contour is not a part of the result. It only shows the place of *S2*.
1678 @figure{/specification/boolean_operations/images/boolean_image046.png,"",230}
1680 * The result of *Cut21* operation is not defined because the dimension of the face (2) is less than the dimension of the solid (3).
1682 @subsubsection specification__boolean_9_4_16 Case 16: A Face and a Solid that have overlapping faces.
1684 Let us consider face *F1* and solid *S2* that have overlapping faces:
1686 @figure{/specification/boolean_operations/images/boolean_image047.png,"",230}
1688 * The result of *Fuse* operation is not defined because the dimension of the face (2) is not equal to the dimension of the solid (3).
1690 * The result of *Common* operation is a compound containing split part of the argument *F1*. In this case the argument face *F1* has a common part with solid *S2*, so the corresponding part of the image of *F1* is included in the result. The yellow contour is not a part of the result. It only shows the place of *S2*.
1692 @figure{/specification/boolean_operations/images/boolean_image048.png,"",230}
1694 * The result of *Cut12* operation is a compound containing split part of the argument *F1*. In this case argument face *F1* has a common part with solid *S2* so the corresponding part is not included into the result. The yellow contour is not a part of the result. It only shows the place of *S2*.
1696 @figure{/specification/boolean_operations/images/boolean_image049.png,"",230}
1698 * The result of *Cut21* operation is not defined because the dimension of the face (2) is less than the dimension of the solid (3).
1701 @subsubsection specification__boolean_9_4_17 Case 17: A Face and a Solid that have overlapping edges.
1703 Let us consider face *F1* and solid *S2* that have overlapping edges:
1705 @figure{/specification/boolean_operations/images/boolean_image050.png,"",230}
1707 * The result of *Fuse* operation is not defined because the dimension of the face (2) is not equal to the dimension of the solid (3).
1709 * The result of *Common* operation is an empty compound because the dimension (1) of the common part between *F1* and *S2* (edge) is less than the lower dimension of the arguments (2).
1711 * The result of *Cut12* operation is a compound containing split part of the argument *F1*. In this case argument face *F1* has a common part with solid *S2* so the corresponding part is not included into the result. The yellow contour is not a part of the result. It only shows the place of *S2*.
1713 @figure{/specification/boolean_operations/images/boolean_image051.png,"",230}
1715 * The result of *Cut21* operation is not defined because the dimension of the face (2) is less than the dimension of the solid (3).
1717 @subsubsection specification__boolean_9_4_18 Case 18: A Face and a Solid that have overlapping vertices.
1719 Let us consider face *F1* and solid *S2* that have overlapping vertices:
1721 @figure{/specification/boolean_operations/images/boolean_image052.png,"",230}
1723 * The result of *Fuse* operation is not defined because the dimension of the face (2) is not equal to the dimension of the solid (3).
1725 * The result of *Common* operation is an empty compound because the dimension (1) of the common part between *F1* and *S2* (vertex) is less than the lower dimension of the arguments (2).
1727 * The result of *Cut12* operation is a compound containing split part of the argument *F1*. In this case argument face *F1* has a common part with solid *S2* so the corresponding part is not included into the result. The yellow contour is not a part of the result. It only shows the place of *S2*.
1729 @figure{/specification/boolean_operations/images/boolean_image053.png,"",230}
1731 * The result of *Cut21* operation is not defined because the dimension of the face (2) is less than the dimension of the solid (3).
1733 @subsubsection specification__boolean_9_4_19 Case 19: Two intersecting Solids.
1735 Let us consider two intersecting solids *S1* and *S2*:
1737 @figure{/specification/boolean_operations/images/boolean_image054.png,"",230}
1739 * The result of *Fuse* operation is a compound composed from the split parts of arguments *S11, S12* and *S22* <i>(Cut12, Common, Cut21)</i>. All inner webs are removed, so the result is one new solid *R*.
1741 @figure{/specification/boolean_operations/images/boolean_image055.png,"",230}
1743 * The result of *Common* operation is a compound containing split parts of arguments i.e. one new solid *S12*. In this case solid *S12* is common for the images of *S1* and *S2*. The common part between the solids (solid) has the same dimension (3) as the dimension of the arguments (3). The yellow contour is not a part of the result. It only shows the place of *S1*.
1745 @figure{/specification/boolean_operations/images/boolean_image056.png,"",176}
1747 * The result of *Cut12* operation is a compound containing split part of the argument *S1*, i.e. 1 new solid *S11*.
1749 @figure{/specification/boolean_operations/images/boolean_image057.png,"",230}
1751 * The result of *Cut21* operation is a compound containing split part of the argument *S2*, i.e. 1 new solid *S21*.
1753 @figure{/specification/boolean_operations/images/boolean_image058.png,"",230}
1755 @subsubsection specification__boolean_9_4_20 Case 20: Two Solids that have overlapping faces.
1757 Let us consider two solids *S1* and *S2* that have a common part on face:
1759 @figure{/specification/boolean_operations/images/boolean_image059.png,"",230}
1761 * The result of *Fuse* operation is a compound composed from the split parts of arguments *S11, S12* and *S22* <i>(Cut12, Common, Cut21)</i>. All inner webs are removed, so the result is one new solid *R*.
1763 @figure{/specification/boolean_operations/images/boolean_image060.png,"",230}
1765 * The result of *Common* operation is an empty compound because the dimension (2) of the common part between *S1* and *S2* (face) is less than the lower dimension of the arguments (3).
1767 * The result of *Cut12* operation is a compound containing split part of the argument *S1*, i.e. 1 new solid *S11*.
1769 @figure{/specification/boolean_operations/images/boolean_image061.png,"",230}
1771 * The result of *Cut21* operation is a compound containing split part of the argument *S2*, i.e. 1 new solid *S21*.
1772 @figure{/specification/boolean_operations/images/boolean_image062.png,"",230}
1775 @subsubsection specification__boolean_9_4_21 Case 21: Two Solids that have overlapping edges.
1777 Let us consider two solids *S1* and *S2* that have overlapping edges:
1779 @figure{/specification/boolean_operations/images/boolean_image063.png,"",230}
1781 * The result of *Fuse* operation is a compound composed from the split parts of arguments i.e. 2 new solids *S11* and *S21*. These solids have one shared edge *En1*.
1783 @figure{/specification/boolean_operations/images/boolean_image064.png,"",230}
1785 * The result of *Common* operation is an empty compound because the dimension (1) of the common part between *S1* and *S2* (edge) is less than the lower dimension of the arguments (3).
1787 * The result of *Cut12* operation is a compound containing split part of the argument *S1*. In this case
1788 argument *S1* has a common part with solid *S2* so the corresponding part is not included into the result.
1790 @figure{/specification/boolean_operations/images/boolean_image065.png,"",230}
1792 * The result of *Cut21* operation is a compound containing split part of the argument *S2*. In this case
1793 argument *S2* has a common part with solid *S1* so the corresponding part is not included into the result.
1795 @figure{/specification/boolean_operations/images/boolean_image066.png,"",230}
1797 @subsubsection specification__boolean_9_4_22 Case 22: Two Solids that have overlapping vertices.
1799 Let us consider two solids *S1* and *S2* that have overlapping vertices:
1801 @figure{/specification/boolean_operations/images/boolean_image067.png,"",230}
1803 * The result of *Fuse* operation is a compound composed from the split parts of arguments i.e. 2 new solids *S11* and *S21*. These solids share *Vn1*.
1805 @figure{/specification/boolean_operations/images/boolean_image068.png,"",230}
1807 * The result of *Common* operation is an empty compound because the dimension (0) of the common part between *S1* and *S2* (vertex) is less than the lower dimension of the arguments (3).
1809 * The result of *Cut12* operation is a compound containing split part of the argument *S1*.
1811 @figure{/specification/boolean_operations/images/boolean_image069.png,"",230}
1813 * The result of *Cut21* operation is a compound containing split part of the argument *S2*.
1815 @figure{/specification/boolean_operations/images/boolean_image070.png,"",230}
1817 @subsubsection specification__boolean_9_4_23 Case 23: A Shell and a Wire cut by a Solid.
1819 Let us consider Shell *Sh* and Wire *W* as the objects and Solid *S* as the tool:
1821 @figure{/specification/boolean_operations/images/boolean_image136.png,"",230}
1823 * The result of *Fuse* operation is not defined as the dimension of the arguments is not the same.
1825 * The result of *Common* operation is a compound containing the parts of the initial Shell and Wire common for the Solid. The new Shell and Wire are created from the objects.
1827 @figure{/specification/boolean_operations/images/boolean_image137.png,"",230}
1829 * The result of *Cut12* operation is a compound containing new Shell and Wire split from the arguments *Sh* and *W*. In this case they have a common part with solid *S* so the corresponding part is not included into the result.
1831 @figure{/specification/boolean_operations/images/boolean_image138.png,"",230}
1833 * The result of *Cut21* operation is not defined as the objects have a lower dimension than the tool.
1835 @subsubsection specification__boolean_9_4_24 Case 24: Two Wires that have overlapping edges.
1837 Let us consider two Wires that have overlapping edges, *W1* is the object and *W2* is the tool:
1839 @figure{/specification/boolean_operations/images/boolean_image139.png,"",230}
1841 * The result of *Fuse* operation is a compound containing two Wires, which share an overlapping edge. The new Wires are created from the objects:
1843 @figure{/specification/boolean_operations/images/boolean_image140.png,"",230}
1845 * The result of *Common* operation is a compound containing one Wire consisting of an overlapping edge. The new Wire is created from the objects:
1847 @figure{/specification/boolean_operations/images/boolean_image141.png,"",230}
1849 * The result of *Cut12* operation is a compound containing a wire split from object *W1*. Its common part with *W2* is not included into the result.
1851 @figure{/specification/boolean_operations/images/boolean_image142.png,"",230}
1853 * The result of *Cut21* operation is a compound containing a wire split from *W2*. Its common part with *W1* is not included into the result.
1855 @figure{/specification/boolean_operations/images/boolean_image143.png,"",230}
1858 @subsection specification__boolean_9_5 Class BOPAlgo_BOP
1860 BOA is implemented in the class *BOPAlgo_BOP*. The main fields of this class are described in the Table:
1864 | *myOperation* | The type of the Boolean operation (Common, Fuse, Cut) |
1865 | *myTools* | The tools |
1866 | *myDims[2]* | The values of the dimensions of the arguments |
1867 | *myRC* | The draft result (shape) |
1869 The main steps of the *BOPAlgo_BOP* are the same as of @ref specification__boolean_7_4 "BOPAlgo_Builder" except for some aspects described in the next paragraphs.
1871 @subsection specification__boolean_9_6 Building Draft Result
1873 The input data for this step is as follows:
1874 * *BOPAlgo_BOP* object after building result of type *Compound*;
1875 * *Type* of the Boolean operation.
1877 | No | Contents | Implementation |
1878 | :---- | :----- | :----- |
1879 | 1 | For the Boolean operation *Fuse* add to *myRC* all images of arguments. | *BOPAlgo_BOP::BuildRC()* |
1880 | 2 | For the Boolean operation *Common* or *Cut* add to *myRC* all images of argument *S1* that are *Common* for the Common operation and are *Not Common* for the Cut operation | *BOPAlgo_BOP::BuildRC()* |
1882 @subsection specification__boolean_9_7 Building the Result
1884 The input data for this step is as follows:
1885 * *BOPAlgo_BOP* object the state after building draft result.
1887 | No | Contents | Implementation |
1888 | :---- | :---- | :------ |
1889 | 1 | For the Type of the Boolean operation Common, Cut with any dimension and operation Fuse with *myDim[0] < 3* | |
1890 | 1.1 | Find containers (WIRE, SHELL, COMPSOLID) in the arguments | *BOPAlgo_BOP:: BuildShape()* |
1891 | 1.2 | Make connexity blocks from splits of each container that are in *myRC* | *BOPTools_Tools::MakeConnexityBlocks()* |
1892 | 1.3 | Build the result from shapes made from the connexity blocks | *BOPAlgo_BOP:: BuildShape()* |
1893 | 1.4 | Add the remaining shapes from *myRC* to the result | *BOPAlgo_BOP:: BuildShape()* |
1894 | 2 | For the Type of the Boolean operation Fuse with *myDim[0] = 3* | |
1895 | 2.1 | Find internal faces <i>(FWi)</i> in *myRC* | *BOPAlgo_BOP::BuildSolid()* |
1896 | 2.2 | Collect all faces of *myRC* except for internal faces <i>(FWi) -> SFS</i> | *BOPAlgo_BOP::BuildSolid ()* |
1897 | 2.3 | Build solids <i>(SDi)</i> from *SFS*. | *BOPAlgo_BuilderSolid* |
1898 | 2.4 | Add the solids <i>(SDi)</i> to the result | |
1900 @subsection specification__boolean_bop_on_opensolids Boolean operations on open solids
1902 The Boolean operations on open solids are tricky enough that the standard approach of Boolean operations for building the result, based on the splits of solids does not work.
1903 It happens because the algorithm for splitting solids (*BOPAlgo_BuilderSolid*) always tries to create the closed loops (shells) and make solids from them. But if the input solid is not closed, what can be expected from its splits?
1904 For performing Boolean Operations on open solids another approach is used, which does not rely on the splits of the solids to be correct, but tries to select the splits of faces, which are necessary for the given type of operation.
1905 The point here is that the type of Boolean operation clearly defines the states for the faces to be taken into result:
1906 - For **COMMON** operation all the faces from the arguments located inside any solid of the opposite group must be taken;
1907 - For **FUSE** operation all the faces from the arguments located outside of all solids of the opposite group must be taken;
1908 - For **CUT** operation all the faces from the Objects located outside of all solids of the Tools and all faces from the Tools located inside any solid of the Objects must be taken;
1909 - For **CUT21** operation all the faces from the Objects located inside any solid of the Tools and all faces from the Tools located outside of all solids of the Objects must be taken.
1910 From the selected faces the result solids are built. Please note, that the result may contain as normal (closed) solids as the open ones.
1912 Even with this approach, the correct result of Boolean operation on open solids cannot be always guaranteed.
1913 This is explained by non-manifold nature of open solids: in some cases classification of a face depends on the point of the face chosen for classification.
1915 @section specification__boolean_10a Section Algorithm
1917 @subsection specification__boolean_10a_1 Arguments
1919 The arguments of BOA are shapes in terms of *TopoDS_Shape*. The main requirements for the arguments are described in the Algorithms.
1921 @subsection specification__boolean_10a_2 Results and general rules
1922 * The result of Section operation is a compound. Each sub-shape of the compound has shared sub-shapes in accordance with interferences between the arguments.
1923 * The result of Section operation contains shapes that have dimension that is less then 2 i.e. vertices and edges.
1924 * The result of Section operation contains standalone vertices if these vertices do not belong to the edges of the result.
1925 * The result of Section operation contains vertices and edges of the arguments (or images of the arguments) that belong to at least two arguments (or two images of the arguments).
1926 * The result of Section operation contains Section vertices and edges obtained from Face/Face interferences.
1927 * The result of Section operation contains vertices that are the result of interferences between vertices and faces.
1928 * The result of Section operation contains edges that are the result of interferences between edges and faces (Common Blocks),
1930 @subsection specification__boolean_10a_3 Examples
1932 @subsubsection specification__boolean_10a_3_1 Case 1: Two Vertices
1934 Let us consider two interfering vertices: *V1* and *V2*.
1936 @figure{/specification/boolean_operations/images/boolean_image080.png,"",131}
1938 The result of *Section* operation is the compound that contains a new vertex *V*.
1940 @figure{/specification/boolean_operations/images/boolean_image081.png,"",128}
1942 @subsubsection specification__boolean_10a_3_2 Case 1: Case 2: A Vertex and an Edge
1944 Let us consider vertex *V1* and the edge *E2*, that intersect in a 3D point:
1946 @figure{/specification/boolean_operations/images/boolean_image082.png,"",230}
1948 The result of *Section* operation is the compound that contains vertex *V1*.
1950 @figure{/specification/boolean_operations/images/boolean_image083.png,"",230}
1952 @subsubsection specification__boolean_10a_3_3 Case 1: Case 2: A Vertex and a Face
1954 Let us consider vertex *V1* and face *F2*, that intersect in a 3D point:
1956 @figure{/specification/boolean_operations/images/boolean_image084.png,"",230}
1958 The result of *Section* operation is the compound that contains vertex *V1*.
1960 @figure{/specification/boolean_operations/images/boolean_image085.png,"",230}
1962 @subsubsection specification__boolean_10a_3_4 Case 4: A Vertex and a Solid
1964 Let us consider vertex *V1* and solid *Z2*. The vertex *V1* is inside the solid *Z2*.
1966 @figure{/specification/boolean_operations/images/boolean_image086.png,"",230}
1968 The result of *Section* operation is an empty compound.
1970 @subsubsection specification__boolean_10a_3_5 Case 5: Two edges intersecting at one point
1972 Let us consider edges *E1* and *E2*, that intersect in a 3D point:
1974 @figure{/specification/boolean_operations/images/boolean_image087.png,"",230}
1976 The result of *Section* operation is the compound that contains a new vertex *Vnew*.
1978 @figure{/specification/boolean_operations/images/boolean_image088.png,"",230}
1980 @subsubsection specification__boolean_10a_3_6 Case 6: Two edges having a common block
1982 Let us consider edges *E1* and *E2*, that have a common block:
1984 @figure{/specification/boolean_operations/images/boolean_image089.png,"",230}
1986 The result of *Section* operation is the compound that contains a new edge *Enew*.
1988 @figure{/specification/boolean_operations/images/boolean_image090.png,"",230}
1990 @subsubsection specification__boolean_10a_3_7 Case 7: An Edge and a Face intersecting at a point
1992 Let us consider edge *E1* and face *F2*, that intersect at a 3D point:
1994 @figure{/specification/boolean_operations/images/boolean_image091.png,"",230}
1996 The result of *Section* operation is the compound that contains a new vertex *Vnew*.
1998 @figure{/specification/boolean_operations/images/boolean_image092.png,"",230}
2000 @subsubsection specification__boolean_10a_3_8 Case 8: A Face and an Edge that have a common block
2002 Let us consider edge *E1* and face *F2*, that have a common block:
2004 @figure{/specification/boolean_operations/images/boolean_image093.png,"",230}
2006 The result of *Section* operation is the compound that contains new edge *Enew*.
2008 @figure{/specification/boolean_operations/images/boolean_image094.png,"",230}
2011 @subsubsection specification__boolean_10a_3_9 Case 9: An Edge and a Solid intersecting at a point
2013 Let us consider edge *E1* and solid *Z2*, that intersect at a point:
2015 @figure{/specification/boolean_operations/images/boolean_image095.png,"",230}
2017 The result of *Section* operation is the compound that contains a new vertex *Vnew*.
2019 @figure{/specification/boolean_operations/images/boolean_image096.png,"",230}
2021 @subsubsection specification__boolean_10a_3_10 Case 10: An Edge and a Solid that have a common block
2023 Let us consider edge *E1* and solid *Z2*, that have a common block at a face:
2025 @figure{/specification/boolean_operations/images/boolean_image097.png,"",230}
2027 The result of *Section* operation is the compound that contains a new edge *Enew*.
2029 @figure{/specification/boolean_operations/images/boolean_image098.png,"",230}
2031 @subsubsection specification__boolean_10a_3_11 Case 11: Two intersecting faces
2033 Let us consider two intersecting faces *F1* and *F2*:
2035 @figure{/specification/boolean_operations/images/boolean_image099.png,"",230}
2037 The result of *Section* operation is the compound that contains a new edge *Enew*.
2039 @figure{/specification/boolean_operations/images/boolean_image100.png,"",230}
2041 @subsubsection specification__boolean_10a_3_12 Case 12: Two faces that have a common part
2043 Let us consider two faces *F1* and *F2* that have a common part:
2045 @figure{/specification/boolean_operations/images/boolean_image133.png,"",230}
2047 The result of *Section* operation is the compound that contains 4 new edges.
2049 @figure{/specification/boolean_operations/images/boolean_image134.png,"",230}
2051 @subsubsection specification__boolean_10a_3_13 Case 13: Two faces that have overlapping edges
2053 Let us consider two faces *F1* and *F2* that have a overlapping edges:
2055 @figure{/specification/boolean_operations/images/boolean_image101.png,"",230}
2057 The result of *Section* operation is the compound that contains a new edge *Enew*.
2059 @figure{/specification/boolean_operations/images/boolean_image102.png,"",230}
2061 @subsubsection specification__boolean_10a_3_14 Case 14: Two faces that have overlapping vertices
2063 Let us consider two faces *F1* and *F2* that have overlapping vertices:
2065 @figure{/specification/boolean_operations/images/boolean_image103.png,"",230}
2067 The result of *Section* operation is the compound that contains a new vertex *Vnew*.
2069 @figure{/specification/boolean_operations/images/boolean_image104.png,"",230}
2071 @subsubsection specification__boolean_10a_3_15 Case 15: A Face and a Solid that have an intersection curve
2073 Let us consider face *F1* and solid *Z2* that have an intersection curve:
2075 @figure{/specification/boolean_operations/images/boolean_image105.png,"",230}
2077 The result of *Section* operation is the compound that contains new edges.
2079 @figure{/specification/boolean_operations/images/boolean_image106.png,"",230}
2081 @subsubsection specification__boolean_10a_3_16 Case 16: A Face and a Solid that have overlapping faces.
2083 Let us consider face *F1* and solid *Z2* that have overlapping faces:
2085 @figure{/specification/boolean_operations/images/boolean_image107.png,"",230}
2087 The result of *Section* operation is the compound that contains new edges
2089 @figure{/specification/boolean_operations/images/boolean_image108.png,"",230}
2091 @subsubsection specification__boolean_10a_3_17 Case 17: A Face and a Solid that have overlapping edges.
2093 Let us consider face *F1* and solid *Z2* that have a common part on edge:
2095 @figure{/specification/boolean_operations/images/boolean_image109.png,"",230}
2097 The result of *Section* operation is the compound that contains a new edge *Enew*.
2099 @figure{/specification/boolean_operations/images/boolean_image110.png,"",230}
2101 @subsubsection specification__boolean_10a_3_18 Case 18: A Face and a Solid that have overlapping vertices.
2103 Let us consider face *F1* and solid *Z2* that have overlapping vertices:
2105 @figure{/specification/boolean_operations/images/boolean_image111.png,"",230}
2107 The result of *Section* operation is the compound that contains a new vertex *Vnew*.
2109 @figure{/specification/boolean_operations/images/boolean_image112.png,"",230}
2111 @subsubsection specification__boolean_10a_3_19 Case 19: Two intersecting Solids
2113 Let us consider two intersecting solids *Z1* and *Z2*:
2114 @figure{/specification/boolean_operations/images/boolean_image113.png,"",230}
2116 The result of *Section* operation is the compound that contains new edges.
2117 @figure{/specification/boolean_operations/images/boolean_image114.png,"",230}
2119 @subsubsection specification__boolean_10a_3_20 Case 20: Two Solids that have overlapping faces
2121 Let us consider two solids *Z1* and *Z2* that have a common part on face:
2122 @figure{/specification/boolean_operations/images/boolean_image115.png,"",230}
2124 The result of *Section* operation is the compound that contains new edges.
2125 @figure{/specification/boolean_operations/images/boolean_image116.png,"",230}
2127 @subsubsection specification__boolean_10a_3_21 Case 21: Two Solids that have overlapping edges
2129 Let us consider two solids *Z1* and *Z2* that have overlapping edges:
2130 @figure{/specification/boolean_operations/images/boolean_image117.png,"",230}
2132 The result of *Section* operation is the compound that contains a new edge *Enew*.
2133 @figure{/specification/boolean_operations/images/boolean_image118.png,"",230}
2135 @subsubsection specification__boolean_10a_3_22 Case 22: Two Solids that have overlapping vertices
2137 Let us consider two solids *Z1* and *Z2* that have overlapping vertices:
2138 @figure{/specification/boolean_operations/images/boolean_image119.png,"",230}
2140 The result of *Section* operation is the compound that contains a new vertex *Vnew*.
2141 @figure{/specification/boolean_operations/images/boolean_image120.png,"",230}
2143 @subsection specification__boolean_10a_4 Class BOPAlgo_Section
2145 SA is implemented in the class *BOPAlgo_Section*. The class has no specific fields.
2146 The main steps of the *BOPAlgo_Section* are the same as of *BOPAlgo_Builder* except for the following steps:
2148 * Build Images for Wires;
2149 * Build Result of Type Wire;
2150 * Build Images for Faces;
2151 * Build Result of Type Face;
2152 * Build Images for Shells;
2153 * Build Result of Type Shell;
2154 * Build Images for Solids;
2155 * Build Result of Type Solid;
2156 * Build Images for Type CompSolid;
2157 * Build Result of Type CompSolid;
2158 * Build Images for Compounds;
2159 Some aspects of building the result are described in the next paragraph
2161 @subsection specification__boolean_10a_5 Building the Result
2163 | No | Contents | Implementation |
2164 | :---- | :---- | :------ |
2165 | 1 | Build the result of the operation using all information contained in *FaceInfo*, Common Block, Shared entities of the arguments, etc. | *BOPAlgo_Section:: BuildSection()* |
2167 @section specification__boolean_10b Volume Maker Algorithm
2169 The Volume Maker algorithm has been designed for building the elementary volumes (solids) from a set of connected, intersecting, or nested shapes. The algorithm can also be useful for splitting solids into parts, or constructing new solid(s) from set of intersecting or connected faces or shells.
2170 The algorithm creates only closed solids. In general case the result solids are non-manifold: fragments of the input shapes (wires, faces) located inside the solids are added as internal sub-shapes to these solids.
2171 But the algorithm allows preventing the addition of the internal for solids parts into result. In this case the result solids will be manifold and not contain any internal parts. However, this option does not prevent from the occurrence of the internal edges or vertices in the faces.<br>
2172 Non-closed faces, free wires etc. located outside of any solid are always excluded from the result.
2174 The Volume Maker algorithm is implemented in the class BOPAlgo_MakerVolume. It is based on the General Fuse (GF) algorithm. All the options of the GF algorithm (see @ref specification__boolean_7_3a "GF Options") are also available in this algorithm.
2176 The requirements for the arguments are the same as for the arguments of GF algorithm - they could be of any type, but each argument should be valid and not self-interfered.
2178 The algorithm allows disabling the calculation of intersections among the arguments. In this case the algorithm will run much faster, but the user should guarantee that the arguments do not interfere with each other, otherwise the result will be invalid (e.g. contain unexpected parts) or empty.
2179 This option is useful e.g. for building a solid from the faces of one shell or from the shapes that have already been intersected.
2181 @subsection specification__boolean_10b_1 Usage
2184 The usage of the algorithm on the API level:
2186 BOPAlgo_MakerVolume aMV;
2187 // Set the arguments
2188 TopTools_ListOfShape aLS = …; // arguments
2189 aMV.SetArguments(aLS);
2191 // Set options for the algorithm
2192 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
2194 // Additional option of the algorithm
2195 Standard_Boolean bAvoidInternalShapes = Standard_False; // Set to True to exclude from the result any shapes internal to the solids
2196 aMV.SetAvoidInternalShapes(bAvoidInternalShapes);
2198 // Perform the operation
2200 if (aMV.HasErrors()) { //check error status
2204 const TopoDS_Shape& aResult = aMV.Shape(); // result of the operation
2208 To use the algorithm in Draw the command mkvolume has been implemented. The usage of this command is following:
2210 Usage: mkvolume r b1 b2 ... [-c] [-ni] [-ai]
2212 -c - use this option to have input compounds considered as set of separate arguments (allows passing multiple arguments as one compound);
2213 -ni - use this option to disable the intersection of the arguments;
2214 -ai - use this option to avoid internal for solids shapes in the result.
2217 @subsection specification__boolean_10b_2 Examples
2220 Creation of 9832 solids from sphere and set of 63 planes:
2222 <table align="center">
2224 <td>@figure{/specification/boolean_operations/images/mkvolume_image001.png,"Arguments",200}</td>
2225 <td>@figure{/specification/boolean_operations/images/mkvolume_image002.png,"Results",200}</td>
2230 Creating compartments on a ship defined by hull shell and a set of planes. The ship is divided on compartments by five transverse bulkheads and a deck – six compartments are created:
2232 <table align="center">
2234 <td>@figure{/specification/boolean_operations/images/mkvolume_image003.png,"Arguments",200}</td>
2235 <td>@figure{/specification/boolean_operations/images/mkvolume_image004.png,"Results",200}</td>
2239 @section specification__boolean_10c_Cells Cells Builder algorithm
2241 The Cells Builder algorithm is an extension of the General Fuse algorithm. The result of General Fuse algorithm contains all split parts of the arguments. The Cells Builder algorithm provides means to specify if any given split part of the arguments (referred to as Cell) can be taken or avoided in the result.
2243 The possibility of selecting any Cell allows combining any possible result and gives the Cells Builder algorithm a very wide sphere of application - from building the result of any Boolean operation to building the result of any application-specific operation.
2245 The algorithm builds Cells only once and then just reuses them for combining the result. This gives this algorithm the performance advantage over Boolean operations, which always rebuild the splits to obtain the desirable result.
2247 Thus, the Cells Builder algorithm can be especially useful for simulating Boolean expressions, i.e. a sequence of Boolean operations on the same arguments. Instead of performing many Boolean operations it allows getting the final result in a single operation. The Cells Builder will also be beneficial to obtain the results of different Boolean operations on the same arguments - Cut and Common, for example.
2249 The Cells Builder algorithm also provides the possibility to remove any internal boundaries between splits of the same type, i.e. to fuse any same-dimensional parts added into the result and to keep any other parts as separate. This possibility is implemented through the Cells material approach: to remove the boundary between two Cells, both Cells should be assigned with the same material ID. However, if the same material ID has been assigned to the Cells of different dimension, the removal of the internal boundaries for that material will not be performed. Currently, such case is considered a limitation for the algorithm.
2251 The algorithm can also create containers from the connected Cells added into result - WIRES from Edges, SHELLS from Faces and COMPSOLIDS from Solids.
2253 @subsection specification__boolean_10c_Cells_1 Usage
2255 The algorithm has been implemented in the *BOPAlgo_CellsBuilder* class.
2257 Cells Builder is based on the General Fuse algorithm. Thus all options of the General Fuse algorithm (see @ref specification__boolean_7_3a "GF Options") are also available in this algorithm.
2259 The requirements for the input shapes are the same as for General Fuse - each argument should be valid in terms of *BRepCheck_Analyzer* and *BOPAlgo_ArgumentAnalyzer*.
2261 The result of the algorithm is a compound containing the selected parts of the basic type (VERTEX, EDGE, FACE or SOLID). The default result is an empty compound. It is possible to add any Cell by using the methods *AddToRessult()* and *AddAllToResult()*. It is also possible to remove any part from the result by using methods *RemoveFromResult()* and *RemoveAllFromResult()*. The method *RemoveAllFromResult()* is also suitable for clearing the result.
2263 The Cells that should be added/removed to/from the result are defined through the input shapes containing the parts that should be taken *(ShapesToTake)* and the ones containing parts that should be avoided (ShapesToAvoid).
2264 To be taken into the result the part must be IN all shapes from *ShapesToTake* and OUT of all shapes from *ShapesToAvoid*.
2266 To remove Internal boundaries, it is necessary to set the same material to the Cells, between which the boundaries should be removed, and call the method *RemoveInternalBoundaries()*.
2267 The material should not be equal to 0, as this is the default material ID. The boundaries between Cells with this material ID will not be removed. The same Cell cannot be added with different materials.
2268 It is also possible to remove the boundaries when the result is combined. To do this, it is necessary to set the material for parts (not equal to 0) and set the flag *bUpdate* to TRUE.
2269 If the same material ID has been set for parts of different dimension, the removal of internal boundaries for this material will not be performed.
2271 It is possible to create typed Containers from the parts added into result by using method *MakeContainers()*. The type of the containers will depend on the type of the input shapes: WIRES for EDGE, SHELLS for FACES and COMPSOLIDS for SOLIDS. The result will be a compound containing containers.
2274 Here is the example of the algorithm use on the API level:
2276 BOPAlgo_CellsBuilder aCBuilder;
2277 // Set the arguments
2278 TopTools_ListOfShape aLS = …; // arguments
2279 aCBuilder.SetArguments(aLS);
2281 // Set options for the algorithm
2282 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
2285 aCBuilder.Perform(); // build splits of all arguments (GF)
2286 if (aCBuilder.HasErrors()) { // check error status
2290 // collecting of the cells into result
2291 const TopoDS_Shape& anEmptyRes = aCBuilder.Shape(); // empty result, as nothing has been added yet
2292 const TopoDS_Shape& anAllCells = aCBuilder.GetAllParts(); //all split parts
2294 TopTools_ListOfShape aLSToTake = ...; // parts of these arguments will be taken into result
2295 TopTools_ListOfShape aLSToAvoid = ...; // parts of these arguments will not be taken into result
2297 Standard_Integer iMaterial = 1; // defines the material for the cells
2298 Standard_Boolean bUpdate = Standard_False; // defines whether to update the result right now or not
2300 aCBuilder.AddToResult(aLSToTake, aLSToAvoid, iMaterial, bUpdate);
2301 aCBuilder.RemoveInternalBoundaries(); // removing of the boundaries
2302 TopoDS_Shape aResult = aCBuilder.Shape(); // the result
2303 // removing from result
2304 aCBuilder.AddAllToResult();
2305 aCBuilder.RemoveFromResult(aLSToTake, aLSToAvoid);
2306 aResult = aCBuilder.Shape(); // the result
2311 The following set of new commands has been implemented to run the algorithm in DRAW Test Harness:
2313 bcbuild : Initialization of the Cells Builder. Use: *bcbuild r*
2314 bcadd : Add parts to result. Use: *bcadd r s1 (0,1) s2 (0,1) ... [-m material [-u]]*
2315 bcaddall : Add all parts to result. Use: *bcaddall r [-m material [-u]]*
2316 bcremove : Remove parts from result. Use: *bcremove r s1 (0,1) s2 (0,1) ...*
2317 bcremoveall : Remove all parts from result. Use: *bcremoveall*
2318 bcremoveint : Remove internal boundaries. Use: *bcremoveint r*
2319 bcmakecontainers : Make containers from the parts added to result. Use: *bcmakecontainers r*
2322 Here is the example of the algorithm use on the DRAW level:
2327 ttranslate s1 0 0 10
2328 ttranslate s2 20 0 10
2329 ttranslate s3 10 0 0
2330 bclearobjects; bcleartools
2331 baddobjects s1 s2 s3
2333 # rx will contain all split parts
2335 # add to result the part that is common for all three spheres
2336 bcadd res s1 1 s2 1 s3 1 -m 1
2337 # add to result the part that is common only for first and third spheres
2338 bcadd res s1 1 s2 0 s3 1 -m 1
2339 # remove internal boundaries
2343 @subsection specification__boolean_10c_Cells_2 Examples
2345 The following simple example illustrates the possibilities of the algorithm working on a cylinder and a sphere intersected by a plane:
2350 plane p 0 0 20 1 0 0
2351 mkface f p -25 30 -17 17
2354 @figure{/specification/boolean_operations/images/cells_algorithm_001.png,"Arguments",160}
2364 #### 1. Common for all arguments
2368 bcadd res c 1 s 1 f 1
2371 @figure{/specification/boolean_operations/images/cells_algorithm_002.png,"The result of COMMON operation",126}
2373 #### 2. Common between cylinder and face
2380 @figure{/specification/boolean_operations/images/cells_algorithm_003.png,"The result of COMMON operation between cylinder and face",90}
2382 #### 3. Common between cylinder and sphere
2389 @figure{/specification/boolean_operations/images/cells_algorithm_004.png,"The result of COMMON operation between cylinder and sphere",120}
2391 #### 4. Fuse of cylinder and sphere
2400 @figure{/specification/boolean_operations/images/cells_algorithm_005.png,"The result of FUSE operation between cylinder and sphere",160}
2402 #### 5. Parts of the face inside solids - FUSE(COMMON(f, c), COMMON(f, s))
2406 bcadd res f 1 s 1 -m 1
2407 bcadd res f 1 c 1 -m 1
2410 @figure{/specification/boolean_operations/images/cells_algorithm_006_1.png,"Parts of the face inside solids",160}
2416 @figure{/specification/boolean_operations/images/cells_algorithm_006_2.png,"Unified parts of the face inside solids",160}
2418 #### 6. Part of the face outside solids
2422 bcadd res f 1 c 0 s 0
2425 @figure{/specification/boolean_operations/images/cells_algorithm_007.png,"Part of the face outside solids",160}
2427 #### 7. Fuse operation (impossible using standard Boolean Fuse operation)
2433 bcadd res f 1 c 0 s 0
2437 @figure{/specification/boolean_operations/images/cells_algorithm_008.png,"Fuse operation",160}
2440 These examples may last forever. To define any new operation, it is just necessary to define, which Cells should be taken and which should be avoided.
2443 @section specification__boolean_10 Algorithm Limitations
2445 The chapter describes the problems that are considered as Algorithm limitations. In most cases an Algorithm failure is caused by a combination of various factors, such as self-interfered arguments, inappropriate or ungrounded values of the argument tolerances, adverse mutual position of the arguments, tangency, etc.
2447 A lot of failures of GFA algorithm can be caused by bugs in low-level algorithms: Intersection Algorithm, Projection Algorithm, Approximation Algorithm, Classification Algorithm, etc.
2448 * The Intersection, Projection and Approximation Algorithms are mostly used at the Intersection step. Their bugs directly cause wrong section results (i.e. incorrect section edges, section points, missing section edges or micro edges). It is not possible to obtain a correct final result of the GFA if a section result is wrong.
2449 * The Projection Algorithm is used at the Intersection step. The purpose of Projection Algorithm is to compute 2D curves on surfaces. Wrong results here lead to incorrect or missing faces in the final GFA result.
2450 * The Classification Algorithm is used at the Building step. The bugs in the Classification Algorithm lead to errors in selecting shape parts (edges, faces, solids) and ultimately to a wrong final GFA result.
2452 The description below illustrates some known GFA limitations. It does not enumerate exhaustively all problems that can arise in practice. Please address cases of Algorithm failure to the OCCT Maintenance Service.
2455 @subsection specification__boolean_10_1 Arguments
2457 @subsubsection specification__boolean_10_1_1 Common requirements
2459 Each argument should be valid (in terms of *BRepCheck_Analyzer*), or conversely, if the argument is considered as non-valid (in terms of *BRepCheck_Analyzer*), it cannot be used as an argument of the algorithm.
2461 The class *BRepCheck_Analyzer* is used to check the overall validity of a shape. In OCCT a Shape (or its sub-shapes) is considered valid if it meets certain criteria. If the shape is found as invalid, it can be fixed by tools from *ShapeAnalysis, ShapeUpgrade* and *ShapeFix* packages.
2463 However, it is important to note that class *BRepCheck_Analyzer* is just a tool that can have its own problems; this means that due to a specific factor(s) this tool can sometimes provide a wrong result.
2465 Let us consider the following example:
2467 The Analyzer checks distances between couples of 3D check-points <i>(Pi, PSi)</i> of edge *E* on face *F*. Point *Pi* is obtained from the 3D curve (at the parameter *ti*) of the edge. *PSi* is obtained from 2D curve (at the parameter *ti*) of the edge on surface *S* of face *F*. To be valid the distance should be less than *Tol(E)* for all couples of check-points. The number of these check-points is a predefined value (e.g. 23).
2469 Let us consider the case when edge *E* is recognized valid (in terms of *BRepCheck_Analyzer*).
2471 Further, after some operation, edge *E* is split into two edges *E1* and *E2*. Each split edge has the same 3D curve and 2D curve as the original edge *E*.
2473 Let us check *E1* (or E2). The Analyzer again checks the distances between the couples of check-points points <i>(Pi, PSi)</i>. The number of these check-points is the same constant value (23), but there is no guarantee that the distances will be less than *Tol(E)*, because the points chosen for *E1* are not the same as for *E*.
2475 Thus, if *E1* is recognized by the Analyzer as non-valid, edge *E* should also be non-valid. However *E* has been recognized as valid. Thus the Analyzer gives a wrong result for *E*.
2477 The fact that the argument is a valid shape (in terms of *BRepCheck_Analyzer*) is a necessary but insufficient requirement to produce a valid result of the Algorithms.
2479 @subsubsection specification__boolean_10_1_3 Pure self-interference
2481 The argument should not be self-interfered, i.e. all sub-shapes of the argument that have geometrical coincidence through any topological entities (vertices, edges, faces) should share these entities.
2483 #### Example 1: Compound of two edges
2484 The compound of two edges *E1* and *E2* is a self-interfered shape and cannot be used as the argument of the Algorithms.
2486 @figure{/specification/boolean_operations/images/operations_image036.svg,"Compound of two edges",230}
2488 #### Example 2: Self-interfered Edge
2489 The edge *E* is a self-interfered shape and cannot be used as an argument of the Algorithms.
2491 @figure{/specification/boolean_operations/images/operations_image037.svg,"Self-interfered Edge",140}
2493 #### Example 3: Self-interfered Face
2494 The face *F* is a self-interfered shape and cannot be used as an argument of the Algorithms.
2496 @figure{/specification/boolean_operations/images/operations_image038.svg,"Self-interfered Face",230}
2498 #### Example 4: Face of Revolution
2499 The face *F* has been obtained by revolution of edge *E* around line *L*.
2501 @figure{/specification/boolean_operations/images/operations_image039a.png,"Face of Revolution: Arguments",230}
2502 @figure{/specification/boolean_operations/images/operations_image039b.png,"Face of Revolution: Result",230}
2504 In spite of the fact that face *F* is valid (in terms of *BRepCheck_Analyzer*) it is a self-interfered shape and cannot be used as the argument of the Algorithms.
2506 @subsubsection specification__boolean_10_1_4 Self-interferences due to tolerances
2507 #### Example 1: Non-closed Edge
2509 Let us consider edge *E* based on a non-closed circle. @figure{/specification/boolean_operations/images/operations_image040.png,"Edge based on a non-closed circle",230}
2511 The distance between the vertices of *E* is *D=0.69799*. The values of the tolerances *Tol(V1)=Tol(V2)=0.5*.
2512 @figure{/specification/boolean_operations/images/operations_image041.png,"Distance and Tolerances",230}
2514 In spite of the fact that the edge *E* is valid in terms of *BRepCheck_Analyzer*, it is a self-interfered shape because its vertices are interfered. Thus, edge *E* cannot be used as an argument of the Algorithms.
2516 #### Example 2: Solid containing an interfered vertex
2518 Let us consider solid *S* containing vertex V. @figure{/specification/boolean_operations/images/operations_image042.png,"Solid containing an interfered vertex",230}
2520 The value of tolerance Tol(V)= 50.000075982061.
2522 @figure{/specification/boolean_operations/images/operations_image043.png,"Tolerance",230}
2524 In spite of the fact that solid *S* is valid in terms of *BRepCheck_Analyzer* it is a self-interfered shape because vertex *V* is interfered with a lot of sub-shapes from *S* without any topological connection with them. Thus solid *S* cannot be used as an argument of the Algorithms.
2526 @subsubsection specification__boolean_10_1_5 Parametric representation
2527 The parameterization of some surfaces (cylinder, cone, surface of revolution) can be the cause of limitation.
2529 #### Example 1: Cylindrical surface
2530 The parameterization range for cylindrical surface is:
2532 @figure{/specification/boolean_operations/images/boolean_image135.png,"",230}
2534 The range of *U* coordinate is always restricted while the range of *V* coordinate is non-restricted.
2536 Let us consider a cylinder-based *Face 1* with radii *R=3* and *H=6*.
2538 @figure{/specification/boolean_operations/images/operations_image044.png,"Face 1",230}
2540 @figure{/specification/boolean_operations/images/operations_image045.png,"P-Curves for Face 1",230}
2542 Let us also consider a cylinder-based *Face 2* with radii *R=3000* and *H=6000* (resulting from scaling Face 1 with scale factor *ScF=1000*).
2544 @figure{/specification/boolean_operations/images/operations_image046.png,"Face 2",230}
2546 @figure{/specification/boolean_operations/images/operations_image047.png,"P-Curves for Face 2",230}
2548 Pay attention to the Zoom value of the Figures.
2550 It is obvious that starting with some value of *ScF*, e.g. *ScF>1000000*, all sloped p-Curves on *Face 2* will be almost vertical. At least, there will be no difference between the values of angles computed by standard C Run-Time Library functions, such as *double acos(double x)*. The loss of accuracy in computation of angles can cause failure of some BP sub-algorithms, such as building faces from a set of edges or building solids from a set of faces.
2553 @subsubsection specification__boolean_10_1_6 Using tolerances of vertices to fix gaps
2555 It is possible to create shapes that use sub-shapes of lower order to avoid gaps in the tolerance-based data model.
2557 Let us consider the following example:
2559 @figure{/specification/boolean_operations/images/operations_image048.png,"Example",230}
2561 * Face *F* has two edges *E1* and *E2* and two vertices, the base plane is <i>{0,0,0, 0,0,1}</i>;
2562 * Edge *E1* is based on line <i>{0,0,0, 1,0,0}, Tol(E1) = 1.e-7; </i>
2563 * Edge *E2* is based on line <i>{0,1,0, 1,0,0}, Tol(E2) = 1.e-7;</i>
2564 * Vertex *V1*, point <i>{0,0.5,0}, Tol(V1) = 1;</i>
2565 * Vertex *V2*, point <i>{10,0.5,0}, Tol(V2) = 1;</i>
2566 * Face *F* is valid (in terms of *BRepCheck_Analyzer*).
2568 The values of tolerances *Tol(V1)* and *Tol(V2)* are big enough to fix the gaps between the ends of the edges, but the vertices *V1* and *V2* do not contain any information about the trajectories connecting the corresponding ends of the edges. Thus, the trajectories are undefined. This will cause failure of some sub-algorithms of BP. For example, the sub-algorithms for building faces from a set of edges use the information about all edges connected in a vertex. The situation when a vertex has several pairs of edges such as above will not be solved in a right way.
2571 @subsection specification__boolean_11_1 Intersection problems
2572 @subsubsection specification__boolean_11_1_1 Pure intersections and common zones
2574 #### Example: Intersecting Edges
2576 Let us consider the intersection between two edges:
2577 * *E1* is based on a line: <i>{0,-10,0, 1,0,0}, Tol(E1)=2.</i>
2578 * *E2* is based on a circle: <i>{0,0,0, 0,0,1}, R=10, Tol(E2)=2.</i>
2580 @figure{/specification/boolean_operations/images/operations_image049.png,"Intersecting Edges",320}
2582 The result of pure intersection between *E1* and *E2* is vertex *Vx {0,-10,0}*.
2584 The result of intersection taking into account tolerances is the common zone *CZ* (part of 3D-space where the distance between the curves is less than or equals to the sum of edge tolerances.
2586 The Intersection Part of Algorithms uses the result of pure intersection *Vx* instead of *CZ* for the following reasons:
2587 * The Algorithms do not produce Common Blocks between edges based on underlying curves of explicitly different type (e.g. Line / Circle). If the curves have different types, the rule of thumb is that the produced result is of type **vertex**. This rule does not work for non-analytic curves (Bezier, B-Spline) and their combinations with analytic curves.
2588 * The algorithm of intersection between two surfaces *IntPatch_Intersection* does not compute *CZ* of the intersection between curves and points. So even if *CZ* were computed by Edge/Edge intersection algorithm, its result could not be treated by Face/Face intersection algorithm.
2590 @subsubsection specification__boolean_11_2_2 Tolerances and inaccuracies
2592 The following limitations result from modeling errors or inaccuracies.
2594 #### Example: Intersection of planar faces
2596 Let us consider two planar rectangular faces *F1* and *F2*.
2598 The intersection curve between the planes is curve *C12*. The curve produces a new intersection edge *EC12*. The edge goes through vertices *V1* and *V2* thanks to big tolerance values of vertices *Tol(V1)* and *Tol(V2)*. So, two straight edges *E12* and *EC12* go through two vertices, which is impossible in this case.
2600 @figure{/specification/boolean_operations/images/operations_image050.svg,"Intersecting Faces",320}
2603 The problem cannot be solved in general, because the length of *E12* can be infinite and the values of *Tol(V1)* and *Tol(V2)* theoretically can be infinite too.
2605 In a particular case the problem can be solved in several ways:
2606 * Reduce, if possible, the values of *Tol(V1)* and *Tol(V2)* (refinement of *F1*).
2607 * Analyze the value of *Tol(EC12)* and increase *Tol(EC12)* to get a common part between the edges *EC12* and *E12*. Then the common part will be rejected as there is an already existing edge *E12* for face *F1*.
2609 It is easy to see that if *C12* is slightly above the tolerance spheres of *V1* and *V2* the problem does not appear.
2611 #### Example: Intersection of two edges
2613 Let us consider two edges *E1* and *E2*, which have common vertices *V1* and *V2*. The edges *E1* and *E2* have 3D-curves *C1* and *C2. Tol(E1)=1.e<sup>-7</sup>, Tol(E2)=1.e<sup>-7</sup>.*
2615 *C1* practically coincides in 3D with *C2*. The value of deflection is *Dmax* (e.g. *Dmax=1.e<sup>-6</sup>*).
2617 @figure{/specification/boolean_operations/images/operations_image051.svg,"Intersecting Edges",420}
2619 The evident and prospective result should be the Common Block between *E1* and *E2*. However, the result of intersection differs.
2621 @figure{/specification/boolean_operations/images/operations_image052.svg,"Result of Intersection",420}
2623 The result contains three new vertices *Vx1, Vx2* and *Vx3*, 8 new edges <i>(V1, Vx1, Vx2, Vx3, V2)</i> and no Common Blocks. This is correct due to the source data: *Tol(E1)=1.e<sup>-7</sup>, Tol(E2)=1.e<sup>-7</sup>* and <i>Dmax=1.e<sup>-6</sup></i>.
2625 In this particular case the problem can be solved by several ways:
2626 * Increase, if possible, the values *Tol(E1)* and *Tol(E2)* to get coincidence in 3D between *E1* and *E2* in terms of tolerance.
2627 * Replace *E1* by a more accurate model.
2629 The example can be extended from 1D (edges) to 2D (faces).
2631 @figure{/specification/boolean_operations/images/operations_image053.svg,"Intersecting Faces",420}
2633 The comments and recommendations are the same as for 1D case above.
2636 @subsubsection specification__boolean_11_2_3 Acquired Self-interferences
2637 #### Example 1: Vertex and edge
2639 Let us consider vertex *V1* and edge *E2*.
2641 @figure{/specification/boolean_operations/images/operations_image054.svg,"Vertex and Edge",171}
2643 Vertex *V1* interferes with vertices *V12* and *V22*.
2644 So vertex *V21* should interfere with vertex *V22*, which is impossible because vertices *V21* and *V22* are the vertices of edge *E2*, thus *V21* is not equal to *V22*.
2646 The problem cannot be solved in general, because the length can be as small as possible to provide validity of *E2* (in the extreme case: *Length (E2) = Tol(V21) + Tol(V22) + e,* where *e-> 0*).
2648 In a particular case the problem can be solved by refinement of arguments, i.e. by decreasing the values of *Tol(V21)*, *Tol(V22)* and *Tol(V1)*.
2650 #### Example 2: Vertex and wire
2652 Let us consider vertex *V2* and wire consisting of edges *E11* and *E12*.
2654 @figure{/specification/boolean_operations/images/operations_image055.svg,"Vertex and Wire",200}
2656 The arguments themselves are not self-intersected.
2657 Vertex *V2* interferes with edges *E11* and *E12*. Thus, edge *E11* should interfere with edge *E22*, but it is impossible because edges *E11* and *E12* cannot interfere by the condition.
2659 The cases when a non-self-interfered argument (or its sub-shapes) become interfered due to the intersections with other arguments (or their sub-shapes) are considered as limitations for the Algorithms.
2661 @section specification__boolean_11a Advanced Options
2663 The previous chapters describe so called Basic Operations. Most of tasks can be solved using Basic Operations. Nonetheless, there are cases that can not be solved straightforwardly by Basic Operations. The tasks are considered as limitations of Basic Operations.
2665 The chapter is devoted to Advanced Options. In some cases the usage of Advanced Options allows overcoming the limitations, improving the quality of the result of operations, robustness and performance of the operators themselves.
2667 @subsection specification__boolean_11a_1 Fuzzy Boolean Operation
2669 Fuzzy Boolean operation is the option of Basic Operations such as General Fuse, Splitting, Boolean, Section, Maker Volume and Cells building operations, in which additional user-specified tolerance is used. This option allows operators to handle robustly cases of touching and near-coincident, misaligned entities of the arguments.
2671 The Fuzzy option is useful on the shapes with gaps or embeddings between the entities of these shapes, which are not covered by the tolerance values of these entities. Such shapes can be the result of modeling mistakes, or translating process, or import from other systems with loss of precision, or errors in some algorithms.
2673 Most likely, the Basic Operations will give unsatisfactory results on such models. The result may contain unexpected and unwanted small entities, faulty entities (in terms of *BRepCheck_Analyzer*), or there can be no result at all.
2675 With the Fuzzy option it is possible to get the expected result -- it is just necessary to define the appropriate value of fuzzy tolerance for the operation. To define that value it is necessary to measure the value of the gap (or the value of embedding depth) between the entities of the models, slightly increase it (to make the shifted entities coincident in terms of their tolerance plus the additional one) and pass it to the algorithm.
2677 Fuzzy option is included in interface of Intersection Part (class *BOPAlgo_PaveFiller*) and application programming interface (class *BRepAlgoAPI_BooleanOperation*)
2679 @subsubsection specification__boolean_11a_1_1 Examples
2680 The following examples demonstrate the advantages of usage Fuzzy option operations over the Basic Operations in typical situations.
2684 In this example the cylinder (shown in yellow and transparent) is subtracted from the box (shown in red). The cylinder is shifted by 5e<sup>-5</sup> relatively to the box along its axis (the distance between rear faces of the box and cylinder is 5e<sup>-5</sup>).
2686 @figure{/specification/boolean_operations/images/boolean_image121.png,"",240}
2688 The following results are obtained using Basic Operations and the Fuzzy ones with the fuzzy value 5e<sup>-5</sup>:
2690 @figure{/specification/boolean_operations/images/boolean_image122.png,"Result of CUT operation obtained with Basic Operations",240}
2692 @figure{/specification/boolean_operations/images/boolean_image123.png,"Result of CUT operation obtained with Fuzzy Option",240}
2694 In this example Fuzzy option allows eliminating a very thin part of the result shape produced by Basic algorithm due to misalignment of rear faces of the box and the cylinder.
2698 In this example two boxes are fused. One of them has dimensions 10*10*10, and the other is 10*10.000001*10.000001 and adjacent to the first one. There is no gap in this case as the surfaces of the neighboring faces coincide, but one box is slightly greater than the other.
2700 @figure{/specification/boolean_operations/images/boolean_image124.png,"",240}
2702 The following results are obtained using Basic Operations and the Fuzzy ones with the fuzzy value 1e<sup>-6</sup>:
2704 @figure{/specification/boolean_operations/images/boolean_image125.png,"Result of CUT operation obtained with Basic Operations",240}
2706 @figure{/specification/boolean_operations/images/boolean_image126.png,"Result of CUT operation obtained with Fuzzy Option",240}
2708 In this example Fuzzy option allows eliminating an extremely narrow face in the result produced by Basic operation.
2712 In this example the small planar face (shown in orange) is subtracted from the big one (shown in yellow). There is a gap 1e<sup>-5</sup> between the edges of these faces.
2714 @figure{/specification/boolean_operations/images/boolean_image127.png,"",240}
2716 The following results are obtained using Basic Operations and the Fuzzy ones with the fuzzy value 1e<sup>-5</sup>:
2718 @figure{/specification/boolean_operations/images/boolean_image128.png,"Result of CUT operation obtained with Basic Operations",240}
2720 @figure{/specification/boolean_operations/images/boolean_image129.png,"Result of CUT operation obtained with Fuzzy Option",240}
2722 In this example Fuzzy options eliminated a pin-like protrusion resulting from the gap between edges of the argument faces.
2726 In this example the small edge is subtracted from the big one. The edges are overlapping not precisely, with max deviation between them equal to 5.28004e<sup>-5</sup>. We will use 6e<sup>-5</sup> value for Fuzzy option.
2728 @figure{/specification/boolean_operations/images/boolean_image130.png,"",240}
2730 The following results are obtained using Basic Operations and the Fuzzy ones with the fuzzy value 6e<sup>-5</sup>:
2732 @figure{/specification/boolean_operations/images/boolean_image131.png,"Result of CUT operation obtained with Basic Operations",240}
2734 @figure{/specification/boolean_operations/images/boolean_image132.png,"Result of CUT operation obtained with Fuzzy Option",240}
2736 This example stresses not only the validity, but also the performance issue. The usage of Fuzzy option with the appropriate value allows processing the case much faster than with the pure Basic operation. The performance gain for the case is 45 (Processor: Intel(R) Core(TM) i5-3450 CPU @ 3.10 GHz).
2738 @subsection specification__boolean_11a_2 Gluing Operation
2740 The Gluing operation is the option of the Basic Operations such as General Fuse, Splitting, Boolean, Section, Maker Volume and Cells building operations.
2741 It has been designed to speed up the computation of the interferences among arguments of the operations on special cases, in which the arguments may be overlapping but do not have real intersections between their sub-shapes.
2743 This option cannot be used on the shapes having real intersections, like intersection vertex between edges, or intersection vertex between edge and a face or intersection line between faces:
2745 @figure{/specification/boolean_operations/images/glue_options_image002.png,"Intersecting faces",240}
2747 There are two possibilities of overlapping shapes:
2748 * The shapes can be partially coinciding - the faces do not have intersection curves, but overlapping. The faces of such arguments will be split during the operation. The following picture illustrates such shapes:
2750 @figure{/specification/boolean_operations/images/glue_options_image001.png,"Partially coinciding faces",240}
2752 * The shapes can be fully coinciding - there should be no partial overlapping of the faces, thus no intersection of type EDGE/FACE at all. In such cases the faces will not be split during the operation.
2754 @figure{/specification/boolean_operations/images/glue_options_image003.png,"Full coinciding faces of the boxes",240}
2756 Thus, there are two possible options - for full and partial coincidence of the shapes.
2758 Even though there are no real intersections on such cases without Gluing options the algorithm will still intersect the sub-shapes of the arguments with interfering bounding boxes.
2760 The performance improvement in gluing mode is achieved by excluding the most time consuming computations and in some case can go up to 90%:
2761 * Exclude computation of FACE/FACE intersections for partial coincidence;
2762 * Exclude computation of VERTEX/FACE, EDGE/FACE and FACE/FACE intersections for full coincidence.
2764 By setting the Gluing option for the operation user should guarantee that the arguments are really coinciding. The algorithm does not check this itself. Setting inappropriate option for the operation is likely to lead to incorrect result.
2766 @subsubsection specification__boolean_11a_2_1 Usage
2768 The Gluing option is an enumeration implemented in BOPAlgo_GlueEnum.hxx:
2769 * BOPAlgo_GlueOff - default value for the algorithms, Gluing is switched off;
2770 * BOPAlgo_GlueShift - Glue option for shapes with partial coincidence;
2771 * BOPAlgo_GlueFull - Glue option for shapes with full coincidence.
2774 For setting the Gluing options for the algorithm it is just necessary to call the SetGlue(const BOPAlgo_Glue) method with appropriate value:
2776 BOPAlgo_Builder aGF;
2779 // setting the gluing option to speed up intersection of the arguments
2780 aGF.SetGlue(BOPAlgo_GlueShift)
2786 For setting the Gluing options in DRAW it is necessary to call the <i>bglue</i> command with appropriate value:
2787 * 0 - default value, Gluing is off;
2788 * 1 - for partial coincidence;
2789 * 2 - for full coincidence
2795 @subsubsection specification__boolean_11a_2_2 Examples
2796 #### Case1 - Fusing the 64 bspline boxes into one solid
2798 @figure{/specification/boolean_operations/images/glue_options_image004.png,"BSpline Boxes with partial coincidence",240}
2800 Performance improvement from using the GlueShift option in this case is about 70 percent.
2802 #### Case2 - Sewing faces of the shape after reading from IGES
2804 @figure{/specification/boolean_operations/images/glue_options_image005.png,"Faces with coinciding but not shared edges",240}
2806 Performance improvement in this case is also about 70 percent.
2808 @subsection specification__boolean_11a_3 Safe processing mode
2810 The safe processing mode is the advanced option in Boolean Operation component. This mode can be applied to all Basic operations such as General Fuse, Splitting, Boolean, Section, Maker Volume, Cells building.
2811 This option allows keeping the input arguments untouched. In other words, switching this option on prevents the input arguments from any modification such as tolerance increase, addition of the P-Curves on edges, etc.
2813 The option can be very useful for implementation of the Undo/Redo mechanism in the applications and allows performing the operation many times without changing the inputs.
2815 By default the safe processing option is switched off for the algorithms. Enabling this option might slightly decrease the performance of the operation, because instead of the modification of some entity it will be necessary to create the copy of this entity and modify it. However, this degradation should be very small because the copying is performed only in case of necessity.
2817 The option is also available in the Intersection algorithm - *BOPAlgo_PaveFiller*. To perform several different operations on the same arguments, the safe processing mode can be enabled in PaveFiller, prepared only once and then used in operations. It is enough to set this option to PaveFiller only and all algorithms taking this PaveFiller will also work in the safe mode.
2819 @subsubsection specification__boolean_11a_3_1 Usage
2823 To enable/disable the safe processing mode for the algorithm, it is necessary to call *SetNonDestructive()* method with the appropriate value:
2825 BOPAlgo_Builder aGF;
2828 // enabling the safe processing mode to prevent modification of the input shapes
2829 aGF.SetNonDestructive(Standard_True);
2835 To enable the safe processing mode for the operation in DRAW, it is necessary to call the <i>bnondestructive</i> command with the appropriate value:
2836 * 0 - default value, the safe mode is switched off;
2837 * 1 - the safe mode will be switched on.
2843 @subsection specification__boolean_11a_4 How to disable check of input solids for inverted status
2845 By default, all input solids are checked for inverted status, i.e. the solids are classified to understand if they are holes in the space (negative volumes) or normal solids (positive volumes). The possibility to disable the check of the input solids for inverted status is the advanced option in Boolean Operation component. This option can be applied to all Basic operations, such as General Fuse, Splitting, Boolean, Section, Maker Volume and Cells building.
2846 This option allows avoiding time-consuming classification of the input solids and processing them in the same way as positive volumes, saving up to 10 percent of time on the cases with a big number of input solids.
2848 The classification should be disabled only if the user is sure that there are no negative volumes among the input solids, otherwise the result may be invalid.
2850 @subsubsection specification__boolean_11a_4_1 Usage
2854 To enable/disable the classification of the input solids it is necessary to call *SetCheckInverted()* method with the appropriate value:
2856 BOPAlgo_Builder aGF;
2859 // disabling the classification of the input solid
2860 aGF.SetCheckInverted(Standard_False);
2866 To enable/disable the classification of the solids in DRAW, it is necessary to call *bcheckinverted* command with the appropriate value:
2867 * 0 - disabling the classification;
2868 * 1 - default value, enabling the classification.
2874 @subsection specification__boolean_11a_5_obb Usage of Oriented Bounding Boxes
2876 Since Oriented Bounding Boxes are usually much tighter than Axes Aligned Bounding Boxes (for more information on OBB see the @ref occt_modat_6 "Bounding boxes" chapter of Modeling data User guide) its usage can significantly speed-up the intersection stage of the operation by reducing the number of interfering objects.
2878 @subsubsection specification__boolean_11a_5_obb_1 Usage
2881 To enable/disable the usage of OBB in the operation it is necessary to call the *SetUseOBB()* method with the appropriate value:
2883 BOPAlgo_Builder aGF;
2886 // Enabling the usage of OBB in the operation
2887 aGF.SetUseOBB(Standard_True);
2893 To enable/disable the usage of OBB in the operation in DRAW it is necessary to call the *buseobb* command with the appropriate value:
2894 * 0 - disabling the usage of OBB;
2895 * 1 - enabling the usage of OBB.
2900 @section specification__boolean_ers Errors and warnings reporting system
2902 The chapter describes the Error/Warning reporting system of the algorithms in the Boolean Component.
2904 The errors and warnings are collected in the instance of the class *Message_Report* maintained as a field by common base class of Boolean operation algorithms *BOPAlgo_Options*.
2906 The error is reported in for problems which cannot be treated and cause the algorithm to fail.
2907 In this case the result of the operation will be incorrect or incomplete or there will be no result at all.
2909 The warnings are reported for the problems which can be potentially handled or ignored and thus do not cause the algorithms to stop their work (but probably affect the result).
2911 All possible errors and warnings that can be set by the algorithm are listed in its header file.
2912 The complete list of errors and warnings that can be generated by Boolean operations is defined in *BOPAlgo_Alerts.hxx*.
2914 Use method *HasErrors()* to check for presence of error; method *HasError()* can be used to check for particular error.
2915 Methods *DumpErrors()* outputs textual description of collected errors into the stream.
2916 Similar methods *HasWarnings()*, *HasWarning()*, and *DumpWarnings()* are provided for warnings.
2918 Note that messages corresponding to errors and warnings are defined in resource file *BOPAlgo.msg*.
2919 These messages can be localized; for that put translated version to separate file and load it in the application by call to *Message_MsgFile::Load()* .
2921 Here is the example of how to use this system:
2923 BOPAlgo_PaveFiller aPF;
2924 aPF.SetArguments(...);
2926 if (aPF.HasErrors()) {
2927 aPF.DumpErrors(std::cerr);
2929 if (aPF.HasError(STANDARD_TYPE(BOPAlgo_AlertNullInputShapes)) {
2932 if (aPF.HasWarning(STANDARD_TYPE(BOPAlgo_AlertTooSmallEdge)) {
2939 DRAW commands executing Boolean operations output errors and warnings generated by these operations in textual form.
2940 Additional option allows saving shapes for which warnings have been generated, as DRAW variables.
2941 To activate this option, run command *bdrawwarnshapes* with argument 1 (or with 0 to deactivate):
2946 After setting this option and running an algorithm the result will look as follows:
2948 Warning: The interfering vertices of the same argument: ws_1_1 ws_1_2
2949 Warning: The positioning of the shapes leads to creation of small edges without valid range: ws_2_1
2953 @section specification__boolean_history History Information
2955 All operations in Boolean Component support @ref occt_modalg_hist "History information". This chapter describes how the History is filled for these operations.
2957 Additionally to Vertices, Edges and Faces the history is also available for the Solids.
2959 The rules for filling the History information about Deleted and Modified shapes are the same as for the API algorithms.
2961 Only the rules for Generated shapes require clarification.
2962 In terms of the algorithms in Boolean Component the shape from the arguments can have Generated shapes only if these new shapes
2963 have been obtained as a result of pure intersection (not overlapping) of this shape with any other shapes from arguments. Thus, the Generated shapes are always:
2964 * VERTICES created from the intersection points and may be Generated from edges and faces only;
2965 * EDGES created from the intersection edges and may be Generated from faces only.
2967 So, only EDGES and FACES could have information about Generated shapes. For all other types of shapes the list of Generated shapes will be empty.
2969 @subsection specification__boolean_history_ex Examples
2971 Here are some examples illustrating the History information.
2973 @subsubsection specification__boolean_history_ex_del Deleted shapes
2975 The result of CUT operation of two overlapping planar faces (see the example below) does not contain any parts from the tool face. Thus, the tool face is considered as Deleted.
2976 If the faces are not fully coinciding, the result must contain some parts of the object face. In this case object face will be considered as not deleted.
2977 But if the faces are fully coinciding, the result must be empty, and both faces will be considered as Deleted.
2979 Example of the overlapping faces:
2983 mkface f1 p -10 10 -10 10
2984 mkface f2 p 0 20 -10 10
2993 savehistory cut_hist
2994 isdeleted cut_hist f1
2997 isdeleted cut_hist f2
3001 @subsubsection specification__boolean_history_ex_modif Modified shapes
3003 In the FUSE operation of two edges intersecting in one point (see the example below), both edges will be split by the intersection point. All these splits will be contained in the result.
3004 Thus, each of the input edges will be Modified into its two splits.
3005 But in the CUT operation on the same edges, the tool edge will be Deleted from the result and, thus, will not have any Modified shapes.
3007 Example of the intersecting edges:
3024 savehistory fuse_hist
3026 modified m1 fuse_hist e1
3030 modified m2 fuse_hist e2
3037 savehistory cut_hist
3039 modified m1 cut_hist e1
3043 modified m2 cut_hist e2
3044 # The shape has not been modified
3048 @subsubsection specification__boolean_history_gen Generated shapes
3050 Two intersecting edges will both have the intersection vertices Generated from them.
3052 As for the operation with intersecting faces, consider the following example:
3055 plane p1 0 0 0 0 0 1
3056 mkface f1 p1 -10 10 -10 10
3058 plane p2 0 0 0 1 0 0
3059 mkface f2 p2 -10 10 -10 10
3070 savehistory fuse_hist
3072 generated gf1 fuse_hist f1
3076 generated gf2 fuse_hist f2
3081 # common operation - result is empty
3084 savehistory com_hist
3086 generated gf1 com_hist f1
3087 # No shapes were generated from the shape
3089 generated gf2 com_hist f2
3090 # No shapes were generated from the shape
3094 @section specification__boolean_simplification BOP result simplification
3096 The API algorithms implementing Boolean Operations provide possibility to simplify the result shape by unification of the connected tangential edges and faces.
3097 This simplification is performed by the method *SimplifyResult* which is implemented in the class *BRepAlgoAPI_BuilderAlgo* (General Fuse operation).
3098 It makes it available for users of the classes *BRepAlgoAPI_BooleanOperation* (all Boolean Operations) and *BRepAlgoAPI_Splitter* (split operation).
3100 The simplification is performed by the means of *ShapeUpgrade_UnifySameDom* algorithm. The result of operation is overwritten with the simplified result.
3102 The simplification is performed without creation of the Internal shapes, i.e. shapes connections will never be broken. It is performed on the whole result shape.
3103 Thus, if the input shapes contained connected tangent edges or faces unmodified during the operation they will also be unified.
3105 History of the simplification is merged into the main history of operation, thus it will be accounted when asking for Modified, Generated and Deleted shapes.
3107 Some options of the main operation are passed into the Unifier:
3108 - Fuzzy tolerance of the operation is given to the Unifier as the linear tolerance.
3109 - Non destructive mode here controls the safe input mode in Unifier.
3111 For controlling this possibility in DRAW the command **bsimplify** has been implemented. See the @ref occt_draw_bop_options "Boolean Operations options" chapter in draw user guide.
3114 @subsection specification__boolean_simplification_examples Examples
3116 Here is the simple example of simplification of the result of Fuse operation of two boxes:
3122 box b2 3 7 0 10 10 15
3131 <table align="center">
3133 <td>@figure{/specification/boolean_operations/images/bop_simple_001.png, "Not simplified result", 420}</td>
3134 <td>@figure{/specification/boolean_operations/images/bop_simple_002.png, "Simplified result", 420}</td>
3139 @section specification__boolean_11b Usage
3141 The chapter contains some examples of the OCCT Boolean Component usage. The usage is possible on two levels: C++ and Tcl.
3143 @subsection specification__boolean_11b_1 Package BRepAlgoAPI
3145 The package *BRepAlgoAPI* provides the Application Programming Interface of the Boolean Component.
3147 The package consists of the following classes:
3148 * *BRepAlgoAPI_Algo* -- the root class that provides the interface for algorithms.
3149 * *BRepAlgoAPI_BuilderAlgo* -- the class API level of General Fuse algorithm.
3150 * *BRepAlgoAPI_Splitter* -- the class API level of the Splitter algorithm.
3151 * *BRepAlgoAPI_BooleanOperation* -- the root class for the classes *BRepAlgoAPI_Fuse*. *BRepAlgoAPI_Common*, *BRepAlgoAPI_Cut* and *BRepAlgoAPI_Section*.
3152 * *BRepAlgoAPI_Fuse* -- the class provides Boolean fusion operation.
3153 * *BRepAlgoAPI_Common* -- the class provides Boolean common operation.
3154 * *BRepAlgoAPI_Cut* -- the class provides Boolean cut operation.
3155 * *BRepAlgoAPI_Section* -- the class provides Boolean section operation.
3157 @figure{/specification/boolean_operations/images/operations_image065.png,"Diagram of BRepAlgoAPI package",420}
3159 The detailed description of the classes can be found in the corresponding .hxx files. The examples are below in this chapter.
3161 @subsection specification__boolean_11b_2 Package BOPTest
3162 The package *BOPTest* provides the usage of the Boolean Component on Tcl level. The method *BOPTest::APICommands* contains corresponding Tcl commands:
3164 * *bapibuild* -- for General Fuse Operator;
3165 * *bapisplit* -- for Splitter Operator;
3166 * *bapibop* -- for Boolean Operator and Section Operator.
3168 The examples of how to use the commands are below in this chapter.
3170 @subsubsection specification__boolean_11b_2_1 Case 1. General Fuse operation
3172 The following example illustrates how to use General Fuse operator:
3177 #include <TopoDS_Shape.hxx>
3178 #include <TopTools_ListOfShape.hxx>
3179 #include <BRepAlgoAPI_BuilderAlgo.hxx>
3181 BRepAlgoAPI_BuilderAlgo aBuilder;
3183 // prepare the arguments
3184 TopTools_ListOfShape& aLS=…;
3186 // set the arguments
3187 aBuilder.SetArguments(aLS);
3189 // Set options for the algorithm
3190 // setting options on this level is similar to setting options to GF algorithm on low level (see "GF Usage" chapter)
3193 // run the algorithm
3195 if (aBuilder.HasErrors()) {
3196 // an error treatment
3200 // result of the operation aR
3201 const TopoDS_Shape& aR=aBuilder.Shape();
3209 # prepare the arguments
3211 box b2 3 4 5 10 10 10
3212 box b3 5 6 7 10 10 10
3214 # clear inner contents
3215 bclearobjects; bcleartools;
3218 baddobjects b1 b2 b3
3220 # set options for the algorithm (see "GF Usage" chapter)
3224 # r is the result of the operation
3228 @subsubsection specification__boolean_11b_2_2 Case 2. Splitting operation
3230 The following example illustrates how to use the Splitter operator:
3235 #include <TopoDS_Shape.hxx>
3236 #include <TopTools_ListOfShape.hxx>
3237 #include <BRepAlgoAPI_Splitter.hxx>
3239 BRepAlgoAPI_BuilderAlgo aSplitter;
3241 // prepare the arguments
3243 TopTools_ListOfShape& aLSObjects = … ;
3245 TopTools_ListOfShape& aLSTools = … ;
3247 // set the arguments
3248 aSplitter.SetArguments(aLSObjects);
3249 aSplitter.SetTools(aLSTools);
3251 // Set options for the algorithm
3252 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
3255 // run the algorithm
3257 // check error status
3258 if (aSplitter.HasErrors()) {
3262 // result of the operation aResult
3263 const TopoDS_Shape& aResult = aSplitter.Shape();
3269 # prepare the arguments
3272 box b2 7 0 0 10 10 10
3275 plane p 10 5 5 0 1 0
3276 mkface f p -20 20 -20 20
3278 # clear inner contents
3279 bclearobjects; bcleartools;
3286 # set options for the algorithm (see "GF Usage" chapter)
3290 # r is the result of the operation
3294 @subsubsection specification__boolean_11b_2_3 Case 3. Common operation
3296 The following example illustrates how to use Common operation:
3301 #include <TopoDS_Shape.hxx>
3302 #include <TopTools_ListOfShape.hxx>
3303 #include < BRepAlgoAPI_Common.hxx>
3305 Standard_Boolean bRunParallel;
3306 Standard_Real aFuzzyValue;
3307 BRepAlgoAPI_Common aBuilder;
3309 // perpare the arguments
3310 TopTools_ListOfShape& aLS=…;
3311 TopTools_ListOfShape& aLT=…;
3313 bRunParallel=Standard_True;
3316 // set the arguments
3317 aBuilder.SetArguments(aLS);
3318 aBuilder.SetTools(aLT);
3320 // Set options for the algorithm
3321 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
3324 // run the algorithm
3326 if (aBuilder.HasErrors()) {
3327 // an error treatment
3331 // result of the operation aR
3332 const TopoDS_Shape& aR=aBuilder.Shape();
3340 # prepare the arguments
3342 box b2 7 0 4 10 10 10
3343 box b3 14 0 0 10 10 10
3345 # clear inner contents
3346 bclearobjects; bcleartools;
3352 # set options for the algorithm (see "GF Usage" chapter)
3356 # r is the result of the operation
3357 # 0 means Common operation
3361 @subsubsection specification__boolean_11b_2_4 Case 4. Fuse operation
3363 The following example illustrates how to use Fuse operation:
3368 #include <TopoDS_Shape.hxx>
3369 #include <TopTools_ListOfShape.hxx>
3370 #include < BRepAlgoAPI_Fuse.hxx>
3372 Standard_Boolean bRunParallel;
3373 Standard_Real aFuzzyValue;
3374 BRepAlgoAPI_Fuse aBuilder;
3376 // perpare the arguments
3377 TopTools_ListOfShape& aLS=…;
3378 TopTools_ListOfShape& aLT=…;
3380 bRunParallel=Standard_True;
3383 // set the arguments
3384 aBuilder.SetArguments(aLS);
3385 aBuilder.SetTools(aLT);
3387 // Set options for the algorithm
3388 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
3391 // run the algorithm
3393 if (aBuilder.HasErrors()) {
3394 // an error treatment
3398 // result of the operation aR
3399 const TopoDS_Shape& aR=aBuilder.Shape();
3407 # prepare the arguments
3409 box b2 7 0 4 10 10 10
3410 box b3 14 0 0 10 10 10
3412 # clear inner contents
3413 bclearobjects; bcleartools;
3419 # set options for the algorithm (see "GF Usage" chapter)
3423 # r is the result of the operation
3424 # 1 means Fuse operation
3428 @subsubsection specification__boolean_11b_2_5 Case 5. Cut operation
3430 The following example illustrates how to use Cut operation:
3435 #include <TopoDS_Shape.hxx>
3436 #include <TopTools_ListOfShape.hxx>
3437 #include < BRepAlgoAPI_Cut.hxx>
3439 Standard_Boolean bRunParallel;
3440 Standard_Real aFuzzyValue;
3441 BRepAlgoAPI_Cut aBuilder;
3443 // perpare the arguments
3444 TopTools_ListOfShape& aLS=…;
3445 TopTools_ListOfShape& aLT=…;
3447 bRunParallel=Standard_True;
3450 // set the arguments
3451 aBuilder.SetArguments(aLS);
3452 aBuilder.SetTools(aLT);
3454 // Set options for the algorithm
3455 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
3458 // run the algorithm
3460 if (aBuilder.HasErrors()) {
3461 // an error treatment
3465 // result of the operation aR
3466 const TopoDS_Shape& aR=aBuilder.Shape();
3474 # prepare the arguments
3476 box b2 7 0 4 10 10 10
3477 box b3 14 0 0 10 10 10
3479 # clear inner contents
3480 bclearobjects; bcleartools;
3486 # set options for the algorithm (see "GF Usage" chapter)
3490 # r is the result of the operation
3491 # 2 means Cut operation
3496 @subsubsection specification__boolean_11b_2_6 Case 6. Section operation
3498 The following example illustrates how to use Section operation:
3503 #include <TopoDS_Shape.hxx>
3504 #include <TopTools_ListOfShape.hxx>
3505 #include < BRepAlgoAPI_Section.hxx>
3507 Standard_Boolean bRunParallel;
3508 Standard_Real aFuzzyValue;
3509 BRepAlgoAPI_Section aBuilder;
3511 // perpare the arguments
3512 TopTools_ListOfShape& aLS=…;
3513 TopTools_ListOfShape& aLT=…;
3515 bRunParallel=Standard_True;
3518 // set the arguments
3519 aBuilder.SetArguments(aLS);
3520 aBuilder.SetTools(aLT);
3522 // Set options for the algorithm
3523 // setting options for this algorithm is similar to setting options for GF algorithm (see "GF Usage" chapter)
3526 // run the algorithm
3528 if (aBuilder.HasErrors()) {
3529 // an error treatment
3533 // result of the operation aR
3534 const TopoDS_Shape& aR=aBuilder.Shape();
3542 # prepare the arguments
3544 box b2 3 4 5 10 10 10
3545 box b3 5 6 7 10 10 10
3547 # clear inner contents
3548 bclearobjects; bcleartools;
3554 # set options for the algorithm (see "GF Usage" chapter)
3558 # r is the result of the operation
3559 # 4 means Section operation