1 Shape Healing {#user_guides__shape_healing}
4 @section occt_shg_1 Overview
6 This manual explains how to use Shape Healing. It provides basic documentation on its operation. For advanced information on Shape Healing and its applications, see our offerings on our web site at <a href="http://www.opencascade.org/support/training/">www.opencascade.org/support/training/</a>
8 The **Shape Healing** toolkit provides a set of tools to work on the geometry and topology of Open CASCADE Technology (**OCCT**) shapes. Shape Healing adapts shapes so as to make them as appropriate for use by Open CASCADE Technology as possible.
9 **Shape Healing** currently includes several packages that are designed to help you to:
10 * analyze shape characteristics and, in particular, identify shapes that do not comply with Open CASCADE Technology validity rules
11 * fix some of the problems shapes may have
12 * upgrade shape characteristics for users needs, for example a C0 supporting surface can be upgraded so that it becomes C1 continuous.
14 The following diagram shows dependencies of API packages:
15 ![](/user_guides/shape_healing/images/shape_healing_image009.png "Shape Healing packages")
17 Each sub-domain has its own scope of functionality:
18 * analysis - exploring shape properties, computing shape features, detecting violation of OCCT requirements (shape itself is not modified);
19 * fixing - fixing shape to meet the OCCT requirements (the shape may change its original form: modifying, removing, constructing sub-shapes, etc.);
20 * upgrade - shape improvement for better usability in Open CASCADE Technology or other algorithms (the shape is replaced with a new one, but geometrically they are the same);
21 * customization - modifying shape representation to fit specific needs (shape is not modified, only the form of its representation is modified);
22 * processing - mechanism of managing shape modification via a user-editable resource file.
24 Message management is used for creating messages, filling them with various parameters and storing them in the trace file. This tool provides functionality for attaching messages to the shapes for deferred analysis of various run-time events. In this document only general principles of using Shape Healing will be described. For more detailed information please see the corresponding CDL files.
25 Tools responsible for analysis, fixing and upgrading of shapes can give the information about how these operations were performed. This information can be obtained by the user with the help of mechanism of status querying.
27 @subsection occt_shg_1_1 Querying the statuses
29 Each fixing and upgrading tool has its own status, which is reset when their methods are called. The status can contain several flags, which give the information about how the method was performed. For exploring the statuses, a set of methods named *Status...()* is provided. These methods accept enumeration *ShapeExtend_Status* and return True if the status has the corresponding flag set. The meaning of flags for each method is described below.
30 The status may contain a set of Boolean flags (internally represented by bits). Flags are coded by enumeration ShapeExtend_Status. This enumeration provides the following families of statuses:
31 | *ShapeExtend_OK* | The situation is OK, no operation is necessary and has not been performed. |
32 | *ShapeExtend_DONE* | The operation has been successfully performed. |
33 | *ShapeExtend_FAIL* | An error has occurred during operation. |
35 It is possible to test the status for the presence of some flag(s), using Status...() method(s) provided by the class:
38 if ( object.Status.. ( ShapeExtend_DONE ) ) {// something was done
42 8 'DONE' and 8 'FAIL' flags, named ShapeExtend_DONE1 ... ShapeExtend_FAIL8, are defined for a detailed analysis of the encountered situation. Each method assigns its own meaning to each flag, documented in the CDL for that method. There are also three enumerative values used for testing several flags at a time:
43 | *ShapeExtend_OK* | if no flags have been set; |
44 | *ShapeExtend_DONE* | if at least one ShapeExtend_DONEi has been set; |
45 | *ShapeExtend_FAIL* | if at least one ShapeExtend_FAILi has been set; |
47 @section occt_shg_2 Repair
49 Algorithms for fixing problematic (violating the OCCT requirements) shapes are placed in package ShapeFix.
50 Each class of package ShapeFix deals with one certain type of shapes or with some family of problems.
51 There is no necessity for you to detect problems before using ShapeFix because all components of package ShapeFix make an analysis of existing problems before fixing them by a corresponding tool from package of ShapeAnalysis and then fix the discovered problems.
52 The ShapeFix package currently includes functions that:
53 * add a 2D curve or a 3D curve where one is missing,
54 * correct a deviation of a 2D curve from a 3D curve when it exceeds a given tolerance value,
55 * limit the tolerance value of shapes within a given range,
56 * set a given tolerance value for shapes,
57 * repair the connections between adjacent edges of a wire,
58 * correct self–intersecting wires,
60 * correct gaps between 3D and 2D curves,
61 * merge and remove small edges,
62 * correct orientation of shells and solids.
64 @subsection occt_shg_2_1 Basic Shape Repair
66 The simplest way for fixing shapes is to use classes *ShapeFix_Shape* and *ShapeFix_Wireframe* on a whole shape with default parameters. A combination of these tools can fix most of the problems that shapes may have.
67 The sequence of actions is as follows :
69 1. Create tool *ShapeFix_Shape* and initialize it by shape:
72 Handle(ShapeFix_Shape) sfs = new ShapeFix_Shape;
76 2. Set the basic precision and the maximum allowed tolerance:
79 sfs->SetPrecision ( Prec );
80 sfs->SetMaxTolerance ( maxTol );
83 Where *Prec* – basic precision, *maxTol* – maximum allowed tolerance.
85 All problems will be detected for cases when a dimension of invalidity is larger than the basic precision or a tolerance of sub-shape on that problem is detected.
86 The maximum tolerance value limits the increasing tolerance for fixing a problem. If a value larger than the maximum allowed tolerance is necessary for correcting a detected problem the problem can not be fixed.
97 TopoDS_Shape aResult = sfs-Shape();
100 In some cases using only *ShapeFix_Shape* can be insufficient. It is possible to use tools for merging and removing small edges and fixing gaps between 2D and 3D curves.
102 5. Create *ShapeFix_Wireframe* tool and initialize it by shape:
105 Handle(ShapeFix_Wirefarme) SFWF = new ShapeFix_Wirefarme(shape);
107 Handle(ShapeFix_Wirefarme) SFWF = new ShapeFix_Wirefarme;
111 6. Set the basic precision and the maximum allowed tolerance:
113 sfs->SetPrecision ( Prec );
114 sfs->SetMaxTolerance ( maxTol );
117 See the description for Prec and maxTol above.
119 7. Merge and remove small edges:
121 SFWF-DropSmallEdgesMode() = Standard_True;
122 SFWF-FixSmallEdges();
125 **Note:** Small edges are not removed with the default mode, but in many cases removing small edges is very useful for fixing a shape.
127 8. Fix gaps for 2D and 3D curves
134 TopoDS_Shape Result = SFWF-Shape();
138 @subsection occt_shg_2_2 Shape Correction.
140 If you do not want to make fixes on the whole shape or make a definite set of fixes you can set flags for separate fix cases (marking them ON or OFF) and you can also use classes for fixing specific types of sub-shapes such as solids, shells, faces, wires, etc.
141 For each type of sub-shapes there are specific types of fixing tools such as *ShapeFix_Solid, ShapeFix_Shell, ShapeFix_Face, ShapeFix_Wire,* etc.
143 @subsubsection occt_shg_2_2_1 Fixing sub-shapes
144 If you want to make a fix on one subshape of a certain shape it is possible to take the following steps:
145 * create a tool for a specified subshape type and initialize this tool by the subshape;
146 * create a tool for rebuilding the shape and initialize it by the whole shape (section 5.1);
147 * set a tool for rebuilding the shape in the tool for fixing the subshape;
149 * get the resulting whole shape containing a new corrected subshape.
151 For example, in the following way it is possible to fix face Face1 of shape Shape1
154 //create tools for fixing a face
155 Handle(ShapeFix_Face) SFF= new ShapeFix_Face;
157 // create tool for rebuilding a shape and initialize it by shape
158 Handle(ShapeBuild_ReShape) Context = new ShapeBuild_ReShape;
159 Context-Apply(Shape1);
161 //set a tool for rebuilding a shape in the tool for fixing
162 SFF-SetContext(Context);
164 //initialize the fixing tool by one face
171 TopoDS_Shape NewShape = Context-Apply(Shape1);
172 //Resulting shape contains the fixed face.
175 A set of required fixes and invalid sub-shapes can be obtained with the help of tools responsible for the analysis of shape validity (section 3.2).
177 @subsection occt_shg_2_3 Repairing tools
179 Each class of package ShapeFix deals with one certain type of shapes or with a family of problems. Each repairing tool makes fixes for the specified shape and its sub-shapes with the help of method *Perform()* containing an optimal set of fixes. The execution of these fixes in the method Perform can be managed with help of a set of control flags (fixes can be either forced or forbidden).
181 @subsubsection occt_shg_2_3_1 General Workflow
183 The following sequence of actions should be applied to perform fixes:
185 2. Set the following values:
186 + the working precision by method *SetPrecision()* (default 1.e-7)
187 + set the maximum allowed tolerance by method *SetMaxTolerance()* (by default it is equal to the working precision).
188 + set the minimum tolerance by method *SetMinTolerance()* (by default it is equal to the working precision).
189 + set a tool for rebuilding shapes after the modification (tool *ShapeBuild_ReShape*) by method *SetContext()*. For separate faces, wires and edges this tool is set optionally.
190 + to force or forbid some of fixes, set the corresponding flag to 0 or 1.
191 3. Initialize the tool by the shape with the help of methods Init or Load
192 4. Use method *Perform()* or create a custom set of fixes.
193 5. Check the statuses of fixes by the general method *Status* or specialized methods *Status_*(for example *StatusSelfIntersection* (*ShapeExtentd_DONE*)). See the description of statuses below.
194 6. Get the result in two ways :
195 - with help of a special method *Shape(),Face(),Wire().Edge()*.
196 - from the rebuilding tool by method *Apply* (for access to rebuilding tool use method *Context()*):
198 TopoDS_Shape resultShape = fixtool-Context()-Apply(initialShape);
200 Modification fistory for the shape and its sub-shapes can be obtained from the tool for shape re-building (*ShapeBuild_ReShape*).
203 TopoDS_Shape modifsubshape = fixtool-Context()
204 -Apply(initsubshape);
208 @subsubsection occt_shg_2_3_2 Flags Management
210 The flags *Fix...Mode()* are used to control the execution of fixing procedures from the API fixing methods. By default, these flags have values equal to -1, this means that the corresponding procedure will either be called or not called, depending on the situation. If the flag is set to 1, the procedure is executed anyway; if the flag is 0, the procedure is not executed. The name of the flag corresponds to the fixing procedure that is controlled. For each fixing tool there exists its own set of flags. To set a flag to the desired value, get a tool containing this flag and set the flag to the required value.
212 For example, it is possible to forbid performing fixes to remove small edges - *FixSmall*
215 Handle(ShapeFix_Shape) Sfs = new ShapeFix_Shape(shape);
216 Sfs- FixWireTool ()-FixSmallMode () =0;
218 TopoDS_Shape resShape = Sfs-Shape();
222 @subsubsection occt_shg_2_3_3 Repairing tool for shapes
224 Class ShapeFix_Shape allows using repairing tools for all sub-shapes of a shape. It provides access to all repairing tools for fixing sub-shapes of the specified shape and to all control flags from these tools.
226 For example, it is possible to force the removal of invalid 2D curves from a face.
229 TopoDS_Face face … // face with invalid 2D curves.
230 //creation of tool and its initialization by shape.
231 Handle(ShapeFix_Shape) sfs = new ShapeFix_Shape(face);
232 //set work precision and max allowed tolerance.
233 sfs->SetPrecision(prec);
234 sfs->SetMaxTolerance(maxTol);
235 //set the value of flag for forcing the removal of 2D curves
236 sfs->FixWireTool()-FixRemovePCurveMode() =1;
240 if(sfs->Status(ShapeExtend_DONE) ) {
241 cout << Shape was fixed << endl;
242 TopoDS_Shape resFace = sfs->Shape();
244 else if(sfs->Status(ShapeExtend_FAIL)) {
245 cout<< Shape could not be fixed << endl;
247 else if(sfs->Status(ShapeExtent_OK)) {
248 cout<< Initial face is valid with specified precision =<< precendl;
252 @subsubsection occt_shg_2_3_4 Repairing tool for solids
254 Class *ShapeFix_Solid* allows fixing solids and building a solid from a shell to obtain a valid solid with a finite volume. The tool *ShapeFix_Shell* is used for correction of shells belonging to a solid.
256 This tool has the following control flags:
257 * *FixShellMode* - Mode for applying fixes of ShapeFix_Shell, True by default.
258 * *CreateOpenShellMode* - If it is equal to true solids are created from open shells, else solids are created from closed shells only, False by default.
260 @subsubsection occt_shg_2_3_5 Repairing tool for shells
261 Class *ShapeFix_Shell* allows fixing wrong orientation of faces in a shell. It changes the orientation of faces in the shell so that all faces in the shell have coherent orientations. If it is impossible to orient all faces in the shell (like in case of Mebious tape), then a few manifold or non-manifold shells will be created depending on the specified Non-manifold mode. The ShapeFix_Face tool is used to correct faces in the shell.
262 This tool has the following control flags:
263 * *FixFaceMode * - mode for applying the fixes of ShapeFix_Face, True by default.
264 * *FixOrientationMode* - mode for applying a fix for the orientation of faces in the shell.
266 @subsubsection occt_shg_2_3_6 Repairing tool for faces
268 Class ShapeFix_Face allows fixing the problems connected with wires of a face. It allows controlling the creation of a face (adding wires), and fixing wires by means of tool *ShapeFix_Wire*.
269 When a wire is added to a face, it can be reordered and degenerated edges can be fixed. This is performed or not depending on the user-defined flags (by default, False).
270 The following fixes are available:
271 * fixing of wires orientation on the face. If the face has no wire, the natural bounds are computed. If the face is on a spherical surface and has two or more wires on it describing holes, the natural bounds are added. In case of a single wire, it is made to be an outer one. If the face has several wires, they are oriented to lay one outside another (if possible). If the supporting surface is periodic, 2D curves of internal wires can be shifted on integer number of periods to put them inside the outer wire.
272 * fixing the case when the face on the closed surface is defined by a set of closed wires, and the seam is missing (this is not valid in Open CASCADE Technology). In that case, these wires are connected by means of seam edges into the same wire.
274 This tool has the following control flags:
275 * *FixWireMode* - mode for applying fixes of a wire, True by default.
276 * *FixOrientationMode* - mode for orienting a wire to border a limited square, True by default.
277 * *FixAddNaturalBoundMode* - mode for adding natural bounds to a face, False by default.
278 * *FixMissingSeamMode* – mode to fix a missing seam, True by default. If True, tries to insert a seam.
279 * *FixSmallAreaWireMode * - mode to fix a small-area wire, False by default. If True, drops wires bounding small areas.
283 TopoDS_Face face = ...;
284 TopoDS_Wire wire = ...;
286 //Creates a tool and adds a wire to the face
287 ShapeFix_Face sff (face);
290 //use method Perform to fix the wire and the face
293 //or make a separate fix for the orientation of wire on the face
294 sff.FixOrientation();
296 //Get the resulting face
297 TopoDS_Face newface = sff.Face();
300 @subsubsection occt_shg_2_3_7 Repairing tool for wires ()
302 Class ShapeFix_Wire allows fixing a wire. Its method Perform() performs all the available fixes in addition to the geometrical filling of gaps. The geometrical filling of gaps can be made with the help of the tool for fixing the wireframe of shape *ShapeFix_Wireframe*.
304 The fixing order and the default behavior of *Perform()* is as follows:
305 * Edges in the wire *FixReorder* are reordered; in case it is forbidden, the analysis of whether the wire is ordered or not is performed anyway (this information is used for determining the default behavior of other methods).
306 * Small edges *FixSmall *are removed.
307 * Edges in the wire are connected (topologically) *FixConnected* (if the wire is ordered).
308 * Edges (3Dcurves and 2D curves) *FixEdgeCurves* (without *FixShifted* if the wire is not ordered) are fixed.
309 * Degenerated edges *FixDegenerated* are added (if the wire is ordered).
310 * Self-intersection *FixSelfIntersection* is fixed (if the wire is ordered and *ClosedMode* is True).
311 * Lacking edges *FixLacking* are fixed (if the wire is ordered).
313 Most of fixing methods expect edges in a wire to be ordered, so it is necessary to make call to *FixReorder()* before making any other fixes.
315 Some fixes can be made in three ways:
316 * Increasing the tolerance of an edge or a vertex.
317 * Changing topology (adding/removing/replacing an edge in the wire and/or replacing the vertex in the edge, copying the edge etc.).
318 * Changing geometry (shifting a vertex or adjusting ends of an edge curve to vertices, or re-computing a 3D curve or 2D curves of the edge).
320 When it is possible to make a fix in more than one way (e.g., either by increasing the tolerance or shifting a vertex), it is chosen according to the user-defined flags:
321 * *ModifyTopologyMode* - allows modifying topology, False by default.
322 * *ModifyGeometryMode* - allows modifying geometry. Now this flag is used only in fixing self-intersecting edges (allows to modify 2D curves) and is True by default.
324 The methods of this class correct the following problems. They:
325 * fix disordered edges in the wire (reorder),
326 * fix small edges (remove edges with a length less than the given value),
327 * fix disconnected edges (adjacent edges having different vertices),
328 * fix the consistency of edge curves,
329 * fix degenerated edges,
330 * fix intersections of 2D curves of the edges,
331 * fix lacking edges to fill gaps in the parametrical space of a surface,
332 * fix gaps in 2D and 3D wires by means of geometrical filling.
334 Fixing disordered edges
335 -----------------------
336 This fix is necessary for most other fixes (but is not necessary for Open CASCADE Technology). It checks whether edges in the wire go in a sequential order (the end of a preceding edge is the start of a following one). If it is not so, an attempt to reorder the edges is made.
340 This fixing method searches for the edges, which have a length less than the given value (degenerated edges are ignored). If such an edge is found, it is removed provided that one of the following conditions is satisfied:
341 * both end vertices of that edge are one and the same vertex,
342 * end vertices of the edge are different, but the flag *ModifyTopologyMode* is True. In the latter case, method *FixConnected* is applied to the preceding and the following edges to ensure their connection.
344 Fixing disconnected edges
345 -------------------------
346 This method forces two adjacent edges to share the same common vertex (if they do not have a common one). It checks whether the end vertex of the preceding edge coincides with the start vertex of the following edge with the given precision, and then creates a new vertex and sets it as a common vertex for the fixed edges. At that point, edges are copied, hence the wire topology is changed (regardless of the *ModifyTopologyMode* flag). If the vertices do not coincide, this method fails.
348 Fixing the consistency of edge curves
349 -------------------------------------
350 This method performs a set of fixes dealing with 3D curves and 2D curves of edges in a wire.
351 These fixes will be activated with the help of a set of fixes from the repairing tool for edges called *ShapeFix_Edge*. Each of these fixes can be forced or forbidden by means of setting the corresponding flag to either True or False. The mentioned fixes and the conditions of their execution are:
352 * fixing a disoriented 2D curve by call to *ShapeFix_Edge::FixReversed2d* - if not forbidden,
353 * removing a wrong 2D curve by call to *ShapeFix_Edge::FixRemovePCurve* - only if forced,
354 * fixing a missing 2D curve by call to *ShapeFix_Edge::FixAddPCurve* - if not forbidden,
355 * removing a wrong 3D curve by call to *ShapeFix_Edge::FixRemoveCurve3d* - only if forced,
356 * fixing a missing 3D curve by call to *ShapeFix_Edge::FixAddCurve3d* - if not forbidden,
357 * fixing 2D curves of seam edges - if not forbidden.
358 * fixing 2D curves which can be shifted at an integer number of periods on the closed surface - if not forbidden. This fix is required if 2D curves of some edges in a wire lying on a closed surface were recomputed from 3D curves. In that case, the 2D curve for the edge, which goes along the seam of the surface, can be incorrectly shifted at an integer number of periods. The method detects such cases and shifts wrong 2D curves back, ensuring that the 2D curves of the edges in the wire are connected,
359 * fixing the SameParameter problem by call to *ShapeFix_Edge::FixSameParameter* - if not forbidden.
361 Fixing degenerated edges
362 ------------------------
363 This method checks whether an edge in a wire lies on a degenerated point of the supporting surface, or whether there is a degenerated point between the edges. If one of these cases is detected for any edge, a new degenerated edge is created and it replaces the current edge in the first case or is added to the wire in the second case. The newly created degenerated edge has a straight 2D curve, which goes from the end of the 2D curve of the preceding edge to the start of the following one.
365 Fixing intersections of 2D curves of the edges
366 ----------------------------------------------
367 This method detects and fixes the following problems:
368 * self-intersection of 2D curves of individual edges. If the flag *ModifyGeometryMode()* is False this fix will be performed by increasing the tolerance of one of end vertices to a value less then *MaxTolerance()*.
369 * intersection of 2D curves of each of the two adjacent edges (except the first and the last edges if the flag ClosedWireMode is False). If such intersection is found, the common vertex is modified in order to comprise the intersection point. If the flag *ModifyTopologyMode* is False this fix will be performed by increasing the tolerance of the vertex to a value less then *MaxTolerance()*.
370 * intersection of 2D curves of non-adjacent edges. If such intersection is found the tolerance of the nearest vertex is increased to comprise the intersection point. If such increase cannot be done with a tolerance less than MaxTolerance this fix will not be performed.
373 Fixing a lacking edge
374 ---------------------
375 This method checks whether a wire is not closed in the parametrical space of the surface (while it can be closed in 3D). This is done by checking whether the gap between 2D curves of each of the two adjacent edges in the wire is smaller than the tolerance of the corresponding vertex. The algorithm computes the gap between the edges, analyses positional relationship of the ends of these edges and (if possible) tries to insert a new edge into the gap or increases the tolerance.
377 Fixing gaps in 2D and 3D wire by geometrical filling
378 ----------------------------------------------------
379 These methods check gaps between the ends of 2D or 3D curves of adjacent edges. Boolean flag *FixGapsByRanges* is used to activate an additional mode applied before converting to B-Splines. When this mode is on, methods try to find the most precise intersection of curves, or the most precise projection of a target point, or an extremity point between two curves (to modify their parametric range accordingly). This mode is off by default. Independently of the additional mode described above, if gaps remain, these methods convert curves to B-Spline form and shift their ends if a gap is detected.
380 Method *FixGap2d* moves the ends of 2D curves to the middle point. Method *FixGaps3d* moves the ends of 3D curves to a common vertex.
382 This tool has the following control flags:
383 * *ClosedWireMode* -specifies whether the wire is (or should be) closed or not. If that flag is True (by default), fixes that require or force connection between edges are executed for the last and the first edges also, otherwise they are not.
386 * *FixConnectedMode, *
387 * *FixEdgeCurvesMode, *
388 * *FixDegeneratedMode, *
389 * *FixSelfIntersectionMode,*
392 The following flags are defined for method *FixEdgeCurves()*:
393 * *FixReversed2dMode, *
394 * *FixRemovePCurveMode, *
395 * *FixRemoveCurve3dMode, *
396 * *FixAddPCurveMode, *
397 * *FixAddCurve3dMode, *
400 * *FixSameParameterMode. *
402 The following flags are defined for method *FixSelfIntersection()*:
403 * *FixSelfIntersectingEdgeMode, *
404 * *FixIntersectingEdgesMode*.
406 Example: A custom set of fixes
407 ------------------------------
409 Let us create a custom set of fixes as an example.
411 TopoDS_Face face = ...;
412 TopoDS_Wire wire = ...;
413 Standard_Real precision = 1e-04;
414 ShapeFix_Wire sfw (wire, face, precision);
415 //Creates a tool and loads objects into it
417 //Orders edges in the wire so that each edge
418 //starts at the end of the one before it
420 //Forces all adjacent edges to share
422 Standard_Boolean LockVertex = Standard_True;
423 if (sfw.FixSmall (LockVertex, precision)) {
424 //Removes all edges which are shorter than
425 //the given precision and have the same vertex at both ends
427 if (sfw.FixSelfIntersection()) {
428 //Fixes self-intersecting edges and intersecting
430 cout;Wire was slightly self-intersecting. Repaired;endl;
432 if ( sfw.FixLacking ( Standard_False ) ) {
433 //Inserts edges to connect adjacent
434 //non-continuous edges
436 TopoDS_Wire newwire = sfw.Wire();
437 //Returns the corrected wire
440 Example: Correction of a wire
441 -----------------------------
443 Let us correct the following wire:
445 ![](/user_guides/shape_healing/images/shape_healing_image013.png "Initial shape")
447 It is necessary to apply the <a href="occt_shg_3_1_2">Tools for the analysis of validity of wires</a> to check that:
448 * the edges are correctly oriented;
449 * there are no edges that are too short;
450 * there are no intersecting adjacent edges;
451 and then immediately apply fixing tools.
454 TopoDS_Face face = ...;
455 TopoDS_Wire wire = ...;
456 Standard_Real precision = 1e-04;
457 ShapeAnalysis_Wire saw (wire, face, precision);
458 ShapeFix_Wire sfw (wire, face, precision);
459 if (saw.CheckOrder()) {
460 cout<<“Some edges in the wire need to be reordered”<<endl;
461 // Two edges are incorrectly oriented
463 cout<<“Reordering is done”<<endl;
465 // their orientation is corrected
466 if (saw.CheckSmall (precision)) {
467 cout<<“Wire contains edge(s) shorter than “<<precision<<endl;
468 // An edge that is shorter than the given
469 // tolerance is found
470 Standard_Boolean LockVertex = Standard_True;
471 if (sfw.FixSmall (LockVertex, precision)) {
472 cout<<“Edges shorter than “<<precision<<“ have been removed”
474 //The edge is removed
477 if (saw.CheckSelfIntersection()) {
478 cout<<“Wire has self-intersecting or intersecting
479 adjacent edges”<<endl;
480 // Two intersecting adjacent edges are found
481 if (sfw.FixSelfIntersection()) {
482 cout<<“Wire was slightly self-intersecting. Repaired”<<endl;
483 // The edges are cut at the intersection point so
484 // that they no longer intersect
489 As the result all failures have been fixed.
491 ![](/user_guides/shape_healing/images/shape_healing_image014.png "Resulting shape")
493 @subsubsection occt_shg_2_3_8 Repairing tool for edges
495 Class *ShapeFix_Edge* provides tools for fixing invalid edges. The following geometrical and/or topological inconsistencies are detected and fixed:
496 * missing 3D curve or 2D curve,
497 * mismatching orientation of a 3D curve and a 2D curve,
498 * incorrect SameParameter flag (curve deviation is greater than the edge tolerance).
499 Each fixing method first checks whether the problem exists using methods of the *ShapeAnalysis_Edge* class. If the problem is not detected, nothing is done.
500 This tool does not have the method *Perform()*.
502 To see how this tool works, it is possible to take an edge, where the maximum deviation between the 3D curve and 2D curve P1 is greater than the edge tolerance.
504 ![](/user_guides/shape_healing/images/shape_healing_image011.png "Initial shape")
506 First it is necessary to apply the <a href="occt_shg_3_1_3">Tool for checking the validity of edges</a> to find that maximum deviation between pcurve and 3D curve is greater than tolerance. Then we can use the repairing tool to increase the tolerance and make the deviation acceptable.
509 ShapeAnalysis_Edge sae;
510 TopoDS_Face face = ...;
511 TopoDS_Wire wire = ...;
512 Standard_Real precision = 1e-04;
514 Standard_Real maxdev;
515 if (sae.CheckSameParameter (edge, maxdev)) {
516 cout<<“Incorrect SameParameter flag”<<endl;
517 cout<<“Maximum deviation “<<maxdev<< “, tolerance “
518 <<BRep_Tool::Tolerance(edge)<<endl;
519 sfe.FixSameParameter();
520 cout<<“New tolerance “<<BRep_Tool::Tolerance(edge)<<endl;
524 ![](/user_guides/shape_healing/images/shape_healing_image012.png "Resulting shape")
526 As the result, the edge tolerance has been increased.
529 @subsubsection occt_shg_2_3_9 Repairing tool for the wireframe of a shape
531 Class *ShapeFix_Wireframe provides methods for geometrical fixing of gaps and merging small edges in a shape. This class performs the following operations:
532 * fills gaps in the 2D and 3D wireframe of a shape.
533 * merges and removes small edges.
535 Fixing of small edges can be managed with the help of two flags:
536 * *ModeDropSmallEdges()* – mode for removing small edges that can not be merged, by default it is equal to Standard_False.
537 * *LimitAngle* – maximum possible angle for merging two adjacent edges, by default no limit angle is applied (-1).
538 To perform fixes it is necessary to:
539 * create a tool and initialize it by shape,
540 * set the working precision problems will be detected with and the maximum allowed tolerance
545 Handle(ShapeFix_Wireframe) sfwf = new ShapeFix_Wireframe(shape);
546 //sets the working precision problems will be detected with and
547 //the maximum allowed tolerance
548 sfwf->SetPrecision(prec);
549 sfwf->SetMaxTolerance(maxTol);
552 //fixing of small edges
553 //setting of the drop mode for the fixing of small edges and max possible angle between merged edges.
554 sfwf->ModeDropSmallEdges = Standard_True;
555 sfwf->SetLimliteAngle(angle);
557 sfwf->FixSmallEdges();
559 TopoDS_Shape resShape = sfwf->Shape();
562 It is desirable that a shape is topologically correct before applying the methods of this class.
564 @subsubsection occt_shg_2_3_10 Tool for removing small faces from a shape
566 Class ShapeFix_FixSmallFaceThis tool is intended for dropping small faces from the shape. The following cases are processed:
567 * Spot face: if the size of the face is less than the given precision;
568 * Strip face: if the size of the face in one dimension is less then the given precision.
570 The sequence of actions for performing the fix is the same as for the fixes described above:
574 Handle(ShapeFix_FixSmallFace) sff = new ShapeFix_FixSmallFace(shape);
575 //setting of tolerances
576 sff->SetPrecision(prec);
577 sff->SetMaxTolerance(maxTol);
581 TopoDS_Shape resShape = sff.FixShape();
584 @subsubsection occt_shg_2_3_11 Tool to modify tolerances of shapes (Class ShapeFix_ShapeTolerance).
586 This tool provides a functionality to set tolerances of a shape and its sub-shapes.
587 In Open CASCADE Technology only vertices, edges and faces have tolerances.
589 This tool allows processing each concrete type of sub-shapes or all types at a time.
590 You set the tolerance functionality as follows:
591 * set a tolerance for sub-shapes, by method SetTolerance,
592 * limit tolerances with given ranges, by method LimitTolerance.
596 ShapeFix_ShapeTolerance Sft;
597 //setting a specified tolerance on shape and all of its sub-shapes.
598 Sft.SetTolerance(shape,toler);
599 //setting a specified tolerance for vertices only
600 Sft.SetTolerance(shape,toler,TopAbs_VERTEX);
601 //limiting the tolerance on the shape and its sub-shapes between minimum and
603 Sft.LimitTolerance(shape,tolermin,tolermax);
607 @section occt_shg_3 Analysis
609 @section occt_shg_3_1 Analysis of shape validity
611 The *ShapeAnalysis* package provides tools for the analysis of topological shapes.
612 It is not necessary to check a shape by these tools before the execution of repairing tools because these tools are used for the analysis before performing fixes inside the repairing tools.
613 However, if you want, these tools can be used for detecting some of shape problems independently from the repairing tools.
614 It can be done in the following way:
615 * create an analysis tool.
616 * initialize it by shape and set a tolerance problems will be detected with if it is necessary.
617 * check the problem that interests you.
620 TopoDS_Face face = ...;
621 ShapeAnalysis_Edge sae;
622 //Creates a tool for analyzing an edge
623 for(TopExp_Explorer Exp(face,TopAbs_EDGE);Exp.More();Exp.Next()) {
624 TopoDS_Edge edge = TopoDS::Edge (Exp.Current());
625 if (!sae.HasCurve3d (edge)) {
626 cout *Edge has no 3D curve* endl; }
630 @subsubsection occt_shg_3_1_1 Analysis of orientation of wires on a face.
632 It is possible to check whether a face has an outer boundary with the help of method *ShapeAnalysis::IsOuterBound*.
635 TopoDS_Face face … //analyzed face
636 if(!ShapeAnalysis::IsOuterBound(face)) {
637 cout*Face has not outer boundary**endl;
641 @subsubsection occt_shg_3_1_2 Analysis of wire validity
643 Class *ShapeAnalysis_Wire* is intended to analyze a wire. It provides functionalities both to explore wire properties and to check its conformance to Open CASCADE Technology requirements.
644 These functionalities include:
645 * checking the order of edges in the wire,
646 * checking for the presence of small edges (with a length less than the given value),
647 * checking for the presence of disconnected edges (adjacent edges having different vertices),
648 * checking the consistency of edge curves,
649 * checking for the presence or missing of degenerated edges,
650 * checking for the presence of self-intersecting edges and intersecting edges (edges intersection is understood as intersection of their 2D curves),
651 * checking for lacking edges to fill gaps in the surface parametrical space,
652 * analyzing the wire orientation (to define the outer or the inner bound on the face),
653 * analyzing the orientation of the shape (edge or wire) being added to an already existing wire.
655 *Note* that all checking operations except for the first one are based on the assumption that edges in the wire are ordered. Thus, if the wire is detected as non-ordered it is necessary to order it before calling other checking operations. This can be done, for example, with the help of the *ShapeFix_Wire::FixOrder()* method.
656 This tool should be initialized with wire, face (or a surface with a location) or precision.
657 Once the tool has been initialized, it is possible to perform the necessary checking operations. In order to obtain all information on a wire at a time the global method *Perform* is provided. It calls all other API checking operations to check each separate case.
658 API methods check for corresponding cases only, the value and the status they return can be analyzed to understand whether the case was detected or not.
659 Some methods in this class are:
660 * *CheckOrder* checks whether edges in the wire are in the right order
661 * *CheckConnected* checks whether edges are disconnected
662 * *CheckSmall* checks whether there are edges that are shorter than the given value
663 * *CheckSelfIntersection* checks, whether there are self-intersecting or adjacent intersecting edges. If the intersection takes place due to nonadjacent edges, it is not detected.
664 This class maintains status management. Each API method stores the status of its last execution which can be queried by the corresponding Status..() method. In addition, each API method returns a Boolean value, which is True when a case being analyzed is detected (with the set ShapeExtend_DONE status), otherwise it is False.
667 TopoDS_Face face = ...;
668 TopoDS_Wire wire = ...;
669 Standard_Real precision = 1e-04;
670 ShapeAnalysis_Wire saw (wire, face, precision);
671 //Creates a tool and loads objects into it
672 if (saw.CheckOrder()) {
673 cout*Some edges in the wire need to be reordered*endl;
674 cout*Please ensure that all the edges are correctly
675 ordered before further analysis*endl;
678 if (saw.CheckSmall (precision)) {
679 cout*Wire contains edge(s) shorter than *precisionendl;
681 if (saw.CheckConnected()) {
682 cout*Wire is disconnected*endl;
684 if (saw.CheckSelfIntersection()) {
685 cout*Wire has self-intersecting or intersecting
686 adjacent edges* endl;
690 @subsubsection occt_shg_3_1_3 Analysis of edge validity
692 Class *ShapeAnalysis_Edge* is intended to analyze edges. It provides the following functionalities to work with an edge:
693 * querying geometrical representations (3D curve and pcurve(s) on a given face or surface),
694 * querying topological sub-shapes (bounding vertices),
695 * checking overlapping edges,
696 * analyzing the curves consistency:
697 + mutual orientation of the 3D curve and 2D curve (co-directions or opposite directions),
698 + correspondence of 3D and 2D curves to vertices.
700 This class supports status management described above.
703 TopoDS_Face face = ...;
704 ShapeAnalysis_Edge sae;
705 //Creates a tool for analyzing an edge
706 for(TopExp_Explorer Exp(face,TopAbs_EDGE);Exp.More();Exp.Next()) {
707 TopoDS_Edge edge = TopoDS::Edge (Exp.Current());
708 if (!sae.HasCurve3d (edge)) {
709 cout *Edge has no 3D curve* endl;
711 Handle(Geom2d_Curve) pcurve;
712 Standard_Real cf, cl;
713 if (sae.PCurve (edge, face, pcurve, cf, cl, Standard_False)) {
714 //Returns the pcurve and its range on the given face
715 cout*Pcurve range [*cf*, *cl*]* endl;
717 Standard_Real maxdev;
718 if (sae.CheckSameParameter (edge, maxdev)) {
719 //Checks the consistency of all the curves
721 cout*Incorrect SameParameter flag*endl;
723 cout*Maximum deviation *maxdev*, tolerance*
724 BRep_Tool::Tolerance(edge)endl;
726 //checks the overlapping of two edges
727 if(sae.CheckOverlapping(edge1,edge2,prec,dist)) {
728 cout*Edges are overlapped with tolerance = *precendl;
729 cout*Domain of overlapping =*distendl;
733 @subsubsection occt_shg_3_1_4 Analysis of presence of small faces
735 Class *ShapeAnalysis_CheckSmallFace* class is intended for analyzing small faces from the shape using the following methods:
736 * *CheckSpotFace()* checks if the size of the face is less than the given precision;
737 * *CheckStripFace* checks if the size of the face in one dimension is less than the given precision.
740 TopoDS_Shape shape … // checked shape
742 ShapeAnalysis_CheckSmallFace saf;
743 //exploring the shape on faces and checking each face
744 Standard_Integer numSmallfaces =0;
745 for(TopExp_Explorer aExp(shape,TopAbs_FACE); aExp.More(); aExp.Next()) {
746 TopoDS_Face face = TopoDS::Face(aexp.Current());
748 if(saf.CheckSpotFace(face,prec) ||
749 saf.CheckStripFace(face,E1,E2,prec))
753 cout*Number of small faces in the shape =* numSmallfaces endl;
756 @subsubsection occt_shg_3_1_5 Analysis of shell validity and closure
758 Class *ShapeAnalysis_Shell* allows checking the orientation of edges in a manifold shell. With the help of this tool, free edges (edges entered into one face) and bad edges (edges entered into the shell twice with the same orientation) can be found. By occurrence of bad and free edges a conclusion about the shell validity and the closure of the shell can be made.
761 TopoDS_Shell shell // checked shape
762 ShapeAnalysis_Shell sas(shell);
763 //analysis of the shell , second parameter is set to True for //getting free edges,(default False)
764 sas.CheckOrientedShells(shell,Standard_True);
765 //getting the result of analysis
766 if(sas.HasBadEdges()) {
767 cout<<"Shell is invalid"<<endl;
768 TopoDS_Compound badEdges = sas.BadEdges();
770 if(sas.HasFreeEdges()) {
771 cout<<"Shell is open"<<endl;
772 TopoDS_Compound freeEdges = sas.FreeEdges();
776 @subsection occt_shg_3_2 Analysis of shape properties.
777 @subsubsection occt_shg_3_2_1 Analysis of tolerance on shape
779 Class *ShapeAnalysis_ShapeTolerance* allows computing tolerances of the shape and its sub-shapes. In Open CASCADE Technology only vertices, edges and faces have tolerances:
781 This tool allows analyzing each concrete type of sub-shapes or all types at a time.
782 The analysis of tolerance functionality is the following:
783 * computing the minimum, maximum and average tolerances of sub-shapes,
784 * finding sub-shapes with tolerances exceeding the given value,
785 * finding sub-shapes with tolerances in the given range.
788 TopoDS_Shape shape = ...;
789 ShapeAnalysis_ShapeTolerance sast;
790 Standard_Real AverageOnShape = sast.Tolerance (shape, 0);
791 cout*Average tolerance of the shape is *AverageOnShapeendl;
792 Standard_Real MinOnEdge = sast.Tolerance (shape,-1,TopAbs_EDGE);
793 cout*Minimum tolerance of the edges is *MinOnEdgeendl;
794 Standard_Real MaxOnVertex = sast.Tolerance (shape,1,TopAbs_VERTEX);
795 cout*Maximum tolerance of the vertices is *MaxOnVertexendl;
796 Standard_Real MaxAllowed = 0.1;
797 if (MaxOnVertex MaxAllowed) {
798 cout*Maximum tolerance of the vertices exceeds
799 maximum allowed*endl;
803 @subsubsection occt_shg_3_2_2 Analysis of free boundaries.
805 Class ShapeAnalysis_FreeBounds is intended to analyze and output the free bounds of a shape. Free bounds are wires consisting of edges referenced only once by only one face in the shape.
806 This class works on two distinct types of shapes when analyzing their free bounds:
807 * Analysis of possible free bounds taking the specified tolerance into account. This analysis can be applied to a compound of faces. The analyzer of the sewing algorithm (*BRepAlgo_Sewing*) is used to forecast what free bounds would be obtained after the sewing of these faces is performed. The following method should be used for this analysis:
809 ShapeAnalysis_FreeBounds safb(shape,toler);
811 * Analysis of already existing free bounds. Actual free bounds (edges shared by the only face in the shell) are output in this case. *ShapeAnalysis_Shell* is used for that.
813 ShapeAnalysis_FreeBounds safb(shape);
815 When connecting edges into wires this algorithm tries to build wires of maximum length. Two options are provided for the user to extract closed sub-contours out of closed and/or open contours. Free bounds are returned as two compounds, one for closed and one for open wires. To obtain a result it is necessary to use methods:
817 TopoDS_Compound ClosedWires = safb.GetClosedWires();
818 TopoDS_Compound OpenWires = safb.GetOpenWires();
820 This class also provides some static methods for advanced use: connecting edges/wires to wires, extracting closed sub-wires from wires, distributing wires into compounds for closed and open wires.
823 TopoDS_Shape shape = ...;
824 Standard_Real SewTolerance = 1.e-03;
825 //Tolerance for sewing
826 Standard_Boolean SplitClosed = Standard_False;
827 Standard_Boolean SplitOpen = Standard_True;
828 //in case of analysis of possible free boundaries
829 ShapeAnalysis_FreeBounds safb (shape, SewTolerance,
830 SplitClosed, SplitOpen);
831 //in case of analysis of existing free bounds
832 ShapeAnalysis_FreeBounds safb (shape, SplitClosed, SplitOpen);
833 //getting the results
834 TopoDS_Compound ClosedWires = safb.GetClosedWires();
835 //Returns a compound of closed free bounds
836 TopoDS_Compound OpenWires = safb.GetClosedWires();
837 //Returns a compound of open free bounds
840 @subsubsection occt_shg_3_2_3 Analysis of shape contents
842 Class ShapeAnalysis_ShapeContents provides tools counting the number of sub-shapes and selecting a sub-shape by the following criteria:
843 Methods for getting the number of sub-shapes:
848 * number of vertices.
849 Methods for calculating the number of geometrical objects or sub-shapes with a specified type:
850 * number of free faces,
851 * number of free wires,
852 * number of free edges,
853 * number of C0 surfaces,
854 * number of C0 curves,
855 * number of BSpline surfaces,… etc
856 and selecting sub-shapes by various criteria.
858 The corresponding flags should be set to True for storing a shape by a specified criteria:
859 * faces based on indirect surfaces - *safc.MofifyIndirectMode() = Standard_True*;
860 * faces based on offset surfaces - *safc.ModifyOffsetSurfaceMode() = Standard_True*;
861 * edges if their 3D curves are trimmed - *safc.ModifyTrimmed3dMode() = Standard_True*;
862 * edges if their 3D curves and 2D curves are offset curves - *safc.ModifyOffsetCurveMode() = Standard_True*;
863 * edges if their 2D curves are trimmed - *safc.ModifyTrimmed2dMode() = Standard_True*;
865 Let us, for example, select faces based on offset surfaces.
868 ShapeAnalysis_ShapeContents safc;
869 //set a corresponding flag for storing faces based on the offset surfaces
870 safc.ModifyOffsetSurfaceMode() = Standard_True;
872 //getting the number of offset surfaces in the shape
873 Standard_Integer NbOffsetSurfaces = safc.NbOffsetSurf();
874 //getting the sequence of faces based on offset surfaces.
875 Handle(TopTools_HSequenceOfShape) seqFaces = safc.OffsetSurfaceSec();
878 @section occt_shg_4 Upgrading
880 Upgrading tools are intended for adaptation of shapes for better use by Open CASCADE Technology or for customization to particular needs, i.e. for export to another system. This means that not only it corrects and upgrades but also changes the definition of a shape with regard to its geometry, size and other aspects. Convenient API allows you to create your own tools to perform specific upgrading. Additional tools for particular cases provide an ability to divide shapes and surfaces according to certain criteria.
882 @subsection occt_shg_4_1 Tools for splitting a shape according to a specified criterion
884 @subsubsection occt_shg_4_1_1 Overview
886 These tools provide such modifications when one topological object can be divided or converted to several ones according to specified criteria. Besides, there are high level API tools for particular cases which:
887 * Convert the geometry of shapes up to a given continuity,
888 * split revolutions by U to segments less than the given value,
889 * convert to Bezier surfaces and Bezier curves,
890 * split closed faces,
891 * convert C0 BSpline curve to a sequence of C1 BSpline curves.
892 All tools for particular cases are based on general tools for shape splitting but each of them has its own tools for splitting or converting geometry in accordance with the specified criteria.
894 General tools for shape splitting are:
895 * tool for splitting the whole shape,
896 * tool for splitting a face,
897 * tool for splitting wires.
898 Tools for shape splitting use tools for geometry splitting:
899 * tool for splitting surfaces,
900 * tool for splitting 3D curves,
901 * tool for splitting 2D curves.
903 @subsubsection occt_shg_4_1_2 Using tools available for shape splitting.
904 If it is necessary to split a shape by a specified continuity, split closed faces in the shape, split surfaces of revolution in the shape by angle or to convert all surfaces, all 3D curves, all 2D curves in the shape to Bezier, it is possible to use the existing/available tools.
905 The usual way to use these tools exception for the tool of converting a C0 BSpline curve is the following:
906 * a tool is created and initialized by shape.
907 * work precision for splitting and the maximum allowed tolerance are set
908 * the value of splitting criterion Is set (if necessary)
909 * splitting is performed.
910 * splitting statuses are obtained.
912 * the history of modification of the initial shape and its sub-shapes is output (this step is optional).
914 Let us, for example, split all surfaces and all 3D and 2D curves having a continuity of less the C2.
917 //create a tool and initializes it by shape.
918 ShapeUpgrade_ShapeDivideContinuity ShapeDivedeCont(initShape);
920 //set the working 3D and 2D precision and the maximum allowed //tolerance
921 ShapeDivideCont.SetTolerance(prec);
922 ShapeDivideCont.SetTolerance2D(prec2d);
923 ShapeDivideCont.SetMaxTolerance(maxTol);
925 //set the values of criteria for surfaces, 3D curves and 2D curves.
926 ShapeDivideCont.SetBoundaryCriterion(GeomAbs_C2);
927 ShapeDivideCont.SetPCurveCriterion(GeomAbs_C2);
928 ShapeDivideCont.SetSurfaceCriterion(GeomAbs_C2);
930 //perform the splitting.
931 ShapeDivideCont.Perform();
933 //check the status and gets the result
934 if(ShapeDivideCont.Status(ShapeExtend_DONE)
935 TopoDS_Shape result = ShapeDivideCont.GetResult();
936 //get the history of modifications made to faces
937 for(TopExp_Explorer aExp(initShape,TopAbs_FACE); aExp.More(0; aExp.Next()) {
938 TopoDS_Shape modifShape = ShapeDivideCont.GetContext()-
939 Apply(aExp.Current());
943 @subsubsection occt_shg_4_1_3 Creation of a new tool for splitting a shape.
944 To create a new splitting tool it is necessary to create tools for geometry splitting according to a desirable criterion. These new tools should be inherited from basic tools for geometry splitting. Then these new tools should be set into corresponding tools for shape splitting.
945 * a new tool for surface splitting should be set into the tool for face splitting
946 * new tools for splitting of 3D and 2D curves should be set into the splitting tool for wires.
947 In order to be able to change the value of criterion of shape splitting it is necessary to create a new tool for shape splitting that should be inherited from the general splitting tool for shapes.
949 Let us split a shape according to a specified criterion.
952 //creation of new tools for geometry splitting by a specified //criterion.
953 Handle(MyTools_SplitSurfaceTool) MySplitSurfaceTool =
954 new MyTools_SplitSurfaceTool;
955 Handle(MyTools_SplitCurve3DTool) MySplitCurve3Dtool =
956 new MyTools_SplitCurve3DTool;
957 Handle(MyTools_SplitCurve2DTool) MySplitCurve2Dtool =
958 new MyTools_SplitCurve2DTool;
960 //creation of a tool for splitting the shape and initialization of //that tool by shape.
961 TopoDS_Shape initShape
962 MyTools_ShapeDivideTool ShapeDivide (initShape);
964 //setting of work precision for splitting and maximum allowed //tolerance.
965 ShapeDivide.SetPrecision(prec);
966 ShapeDivide.SetMaxTolerance(MaxTol);
968 //setting of new splitting geometry tools in the shape splitting //tools
969 Handle(ShapeUpgrade_FaceDivide) FaceDivide =
970 ShapeDivide-GetSplitFaceTool();
971 Handle(ShapeUpgrade_WireDivide) WireDivide =
972 FaceDivide-GetWireDivideTool();
973 FaceDivide-SetSplitSurfaceTool(MySplitSurfaceTool);
974 WireDivide-SetSplitCurve3dTool(MySplitCurve3DTool);
975 WireDivide-SetSplitCurve2dTool(MySplitCurve2DTool);
977 //setting of the value criterion.
978 ShapeDivide.SetValCriterion(val);
981 ShapeDivide.Perform();
984 TopoDS_Shape splitShape = ShapeDivide.GetResult();
986 //getting the history of modifications of faces
987 for(TopExp_Explorer aExp(initShape,TopAbs_FACE); aExp.More(0; aExp.Next()) {
988 TopoDS_Shape modifShape = ShapeDivide.GetContext()-
989 Apply(aExp.Current());
993 @subsection occt_shg_4_2 General splitting tools.
995 @subsubsection occt_shg_4_2_1 General tool for shape splitting
997 Class *ShapeUpgrade_ShapeDivide* provides shape splitting and converting according to the given criteria. It performs these operations for each face with the given tool for face splitting (*ShapeUpgrade_FaceDivide* by default).
998 This tool provides access to the tool for dividing faces with the help of the following methods:
1002 @subsubsection occt_shg_4_2_2 General tool for face splitting
1003 Class *ShapeUpgrade_FaceDivide* divides a Face (edges in the wires, by splitting 3D and 2D curves, as well as the face itself, by splitting the supporting surface) according to the given criteria.
1004 The area of the face intended for division is defined by 2D curves of the wires on the Face.
1005 All 2D curves are supposed to be defined (in the parametric space of the supporting surface).
1006 The result is available after the call to the *Perform* method. It is a Shell containing all resulting Faces. All modifications made during the splitting operation are recorded in the external context (*ShapeBuild_ReShape*).
1007 This tool provides access to the tool for wire division and surface splitting by means of methods:
1008 *SetWireDivideTool,*
1009 *GetWireDivideTool,*
1010 *SetSurfaceSplitTool,*
1011 *GetSurfaceSplitTool*.
1013 @subsubsection occt_shg_4_2_3 General tool for wire splitting
1014 Class *ShapeUpgrade_WireDivide* divides edges in the wire lying on the face or free wires or free edges with a given criterion. It splits the 3D curve and 2D curve(s) of the edge on the face. Other 2D curves, which may be associated with the edge, are simply copied. If the 3D curve is split then the 2D curve on the face is split as well, and vice-versa. The original shape is not modified. Modifications made are recorded in the context (*ShapeBuild_ReShape*).
1015 This tool provides access to the tool for dividing and splitting 3D and 2D curves by means of methods:
1017 *GetEdgeDivideTool,*
1018 *SetSplitCurve3dTool,*
1019 *GetSplitCurve3dTool,*
1020 *SetSplitCurve2dTool,*
1021 *GetSplitCurve2dTool*
1022 and it also provides access to the mode for splitting edges by methods:
1025 This mode sets whether only free edges, only shared edges or all edges are split.
1027 @subsubsection occt_shg_4_2_4 General tool for edge splitting
1028 Class *ShapeUpgrade_EdgeDivide* divides edges and their geometry according to the specified criteria. It is used in the wire-dividing tool.
1029 This tool provides access to the tool for dividing and splitting 3D and 2D curves by the following methods:
1030 *SetSplitCurve3dTool,*
1031 *GetSplitCurve3dTool,*
1032 *SetSplitCurve2dTool,*
1033 *GetSplitCurve2dTool*.
1035 @subsubsection occt_shg_4_2_5 General tools for geometry splitting
1036 There are three general tools for geometry splitting.
1037 * General tool for surface splitting.(*ShapeUpgrade_SplitSurface*)
1038 * General tool for splitting 3D curves.(*ShapeUpgrade_SplitCurve3d*)
1039 * General tool for splitting 2D curves.(*ShapeUpgrade_SplitCurve2d*)
1040 All these tools are constructed the same way:
1042 * for initializing by geometry (method *Init*)
1043 * for splitting (method *Perform*)
1044 * for getting the status after splitting and the results:
1045 + *Status – *for getting the result status*,*
1046 + *ResSurface* - for splitting surfaces.
1047 + *GetCurves* - for splitting 3D and 2D curves.
1048 During the process of splitting in the method *Perform* :
1049 * splitting values in the parametric space are computed according to a specified criterion (method *Compute*)
1050 * splitting is made in accordance with the values computed for splitting (method *Build*).
1052 To create new tools for geometry splitting it is enough to inherit a new tool from the general tool for splitting a corresponding type of geometry and to re-define the method for computation of splitting values according to the specified criterion in them. (method *Compute*).
1054 Header file for the tool for surface splitting by continuity:
1057 class ShapeUpgrade_SplitSurfaceContinuity : public ShapeUpgrade_SplitSurface {
1058 Standard_EXPORT ShapeUpgrade_SplitSurfaceContinuity();
1060 //methods to set the criterion and the tolerance into the splitting //tool
1061 Standard_EXPORT void SetCriterion(const GeomAbs_Shape Criterion) ;
1062 Standard_EXPORT void SetTolerance(const Standard_Real Tol) ;
1064 //re-definition of method Compute
1065 Standard_EXPORT virtual void Compute(const Standard_Boolean Segment) ;
1066 Standard_EXPORT ~ShapeUpgrade_SplitSurfaceContinuity();
1068 GeomAbs_Shape myCriterion;
1069 Standard_Real myTolerance;
1070 Standard_Integer myCont;
1074 @subsection occt_shg_4_3 Specific splitting tools.
1076 @subsubsection occt_shg_4_3_1 Conversion of shape geometry to the target continuity
1077 Class *ShapeUpgrade_ShapeDivideContinuity* allows converting geometry with continuity less than the specified continuity to geometry with target continuity. If converting is not possible than geometrical object is split into several ones, which satisfy the given criteria. A topological object based on this geometry is replaced by several objects based on the new geometry.
1080 ShapeUpgrade_ShapeDivideContinuity sdc (shape);
1081 sdc.SetTolerance (tol3d);
1082 sdc.SetTolerance3d (tol2d); // if known, else 1.e-09 is taken
1083 sdc.SetBoundaryCriterion (GeomAbs_C2); // for Curves 3D
1084 sdc.SetPCurveCriterion (GeomAbs_C2); // for Curves 2D
1085 sdc.SetSurfaceCriterion (GeomAbs_C2); // for Surfaces
1087 TopoDS_Shape bshape = sdc.Result();
1088 .. to also get the correspondances before/after
1089 Handle(ShapeBuild_ReShape) ctx = sdc.Context();
1091 if (ctx.IsRecorded (sh)) {
1092 TopoDS_Shape newsh = ctx->Value (sh);
1093 // if there are several results, they are re-recorded inside a Compound
1094 // .. process as needed
1098 @subsubsection occt_shg_4_3_2 Splitting by angle
1099 Class *ShapeUpgrade_ShapeDivideAngle* allows splitting all surfaces of revolution, cylindrical, toroidal, conical, spherical surfaces in the given shape so that each resulting segment covers not more than the defined angle (in radians).
1101 @subsubsection occt_shg_4_3_3 Conversion of 2D, 3D curves and surfaces to Bezier
1103 Class *ShapeUpgrade_ShapeConvertToBezier* is an API tool for performing a conversion of 3D, 2D curves to Bezier curves and surfaces to Bezier based surfaces (Bezier surface, surface of revolution based on Bezier curve, offset surface based on any of previous types).
1104 This tool provides access to various flags for conversion of different types of curves and surfaces to Bezier by methods:
1108 *Set3dLineConversion,*
1109 *Get3dLineConversion,*
1110 *Set3dCircleConversion,*
1111 *Get3dCircleConversion,*
1112 *Set3dConicConversion,*
1113 *Get3dConicConversion*
1118 *GetSurfaceConversion,*
1121 *SetRevolutionMode,*
1122 *GetRevolutionMode,*
1128 Let us attempt to produce a conversion of planes to Bezier surfaces.
1130 //Creation and initialization of a tool.
1131 ShapeUpgrade_ShapeConvertToBezier SCB (Shape);
1132 //setting tolerances
1134 //setting mode for conversion of planes
1135 SCB.SetSurfaceConversion (Standard_True);
1136 SCB.SetPlaneMode(Standard_True);
1138 If(SCB.Status(ShapeExtend_DONE)
1139 TopoDS_Shape result = SCB.GetResult();
1142 @subsubsection occt_shg_4_3_4 Tool for splitting closed faces
1144 Class *ShapeUpgrade_ShapeDivideClosed* provides splitting of closed faces in the shape to a defined number of components by the U and V parameters. It topologically and (partially) geometrically processes closed faces and performs splitting with the help of class *ShapeUpgrade_ClosedFaceDivide*.
1147 TopoDS_Shape aShape = …;
1148 ShapeUpgrade_ShapeDivideClosed tool (aShape );
1149 Standard_Real closeTol = …;
1150 tool.SetPrecision(closeTol);
1151 Standard_Real maxTol = …;
1152 tool.SetMaxTolerance(maxTol);
1153 Standard_Integer NbSplitPoints = …;
1154 tool.SetNbSplitPoints(num);
1155 if ( ! tool.Perform() && tool.Status (ShapeExtend_FAIL) ) {
1156 cout;Splitting of closed faces failed;endl;
1159 TopoDS_Shape aResult = tool.Result();
1162 @subsubsection occt_shg_4_3_5 Tool for splitting a C0 BSpline 2D or 3D curve to a sequence C1 BSpline curves
1164 The API methods for this tool is a package of methods *ShapeUpgrade::C0BSplineToSequenceOfC1BsplineCurve*, which converts a C0 B-Spline curve into a sequence of C1 B-Spline curves. This method splits a B-Spline at the knots with multiplicities equal to degree, it does not use any tolerance and therefore does not change the geometry of the B-Spline. The method returns True if C0 B-Spline was successfully split, otherwise returns False (if BS is C1 B-Spline).
1166 @subsubsection occt_shg_4_3_6 Tool for splitting faces
1168 *ShapeUpgrade_ShapeDivideArea* can work with compounds, solids, shells and faces.
1169 During the work this tool examines each face of a specified shape and if the face area exceeds the specified maximal area, this face is divided. Face splitting is performed in the parametric space of this face. The values of splitting in U and V directions are calculated with the account of translation of the bounding box form parametric space to 3D space. Such calculations are necessary to avoid creation of strip faces. In the process of splitting the holes on the initial face are taken into account. After the splitting all new faces are checked by area again and the splitting procedure is repeated for the faces whose area still exceeds the max allowed area. Sharing between faces in the shape is preserved and the resulting shape is of the same type as the source shape.
1170 An example of using this tool is presented in the figures below:
1172 ![](/user_guides/shape_healing/images/shape_healing003.jpg "Source Face")
1174 ![](/user_guides/shape_healing/images/shape_healing004.jpg "Resulting shape")
1177 *ShapeUpgrade_ShapeDivideArea* is inherited from the base class *ShapeUpgrade_ShapeDivide* and should be used in the following way:
1178 * This class should be initialized on a shape with the help of the constructor or method *Init()* from the base class.
1179 * The maximal allowed area should be specified by the method *MaxArea()*.
1180 * To produce a splitting use method Perform from the base class.
1181 * The result shape can be obtained with the help the method *Result()*.
1184 ShapeUpgrade_ShapeDivideArea tool (inputShape);
1185 tool.MaxArea() = aMaxArea;
1187 if(tool.Status(ShapeExtend_DONE)) {
1188 TopoDS_Shape ResultShape = tool.Result();
1189 ShapeFix::SameParameter ( ResultShape, Standard_False );
1193 **Note** that the use of method *ShapeFix::SameParameter* is necessary, otherwise the parameter edges obtained as a result of splitting can be different.
1197 * Class *ShapeUpgrade_FaceDivideArea* inherited from *ShapeUpgrade_FaceDivide* is intended for splitting a face by the maximal area criterion.
1198 * Class *ShapeUpgrade_SplitSurfaceArea* inherited from *ShapeUpgrade_SplitSurface* calculates the parameters of face splitting in the parametric space.
1201 @subsection occt_shg_4_4 Customization of shapes
1203 Customization tools are intended for adaptation of shape geometry in compliance with the customer needs. They modify a geometrical object to another one in the shape.
1205 To implement the necessary shape modification it is enough to initialize the appropriate tool by the shape and desirable parameters and to get the resulting shape. For example for conversion of indirect surfaces in the shape do the following:
1208 TopoDS_Shape initialShape ..
1209 TopoDS_Shape resultShape = ShapeCustom::DirectFaces(initialShape);
1212 @subsubsection occt_shg_4_2_1 Conversion of indirect surfaces.
1215 ShapeCustom::DirectFaces
1216 static TopoDS_Shape DirectFaces(const TopoDS_Shape& S);
1219 This method provides conversion of indirect elementary surfaces (elementary surfaces with left-handed coordinate systems) in the shape into direct ones. New 2d curves (recomputed for converted surfaces) are added to the same edges being shared by both the resulting shape and the original shape S.
1221 @subsubsection occt_shg_4_2_2 Shape Scaling
1224 ShapeCustom::ScaleShape
1225 TopoDS_Shape ShapeCustom::ScaleShape(const TopoDS_Shape& S,
1226 const Standard_Real scale);
1229 This method returns a new shape, which is a scaled original shape with a coefficient equal to the specified value of scale. It uses the tool *ShapeCustom_TrsfModification*.
1231 @subsubsection occt_shg_4_2_3 Conversion of curves and surfaces to BSpline
1232 *ShapeCustom_BSplineRestriction.* allows approximation of surfaces, curves and 2D curves with a specified degree, max number of segments, 2d tolerance and 3d tolerance. If the approximation result cannot be achieved with the specified continuity, the latter can be reduced.
1234 The method with all parameters looks as follows:
1236 ShapeCustom::BsplineRestriction
1237 TopoDS_Shape ShapeCustom::BSplineRestriction (const TopoDS_Shape& S,
1238 const Standard_Real Tol3d, const Standard_Real Tol2d,
1239 const Standard_Integer MaxDegree,
1240 const Standard_Integer MaxNbSegment,
1241 const GeomAbs_Shape Continuity3d,
1242 const GeomAbs_Shape Continuity2d,
1243 const Standard_Boolean Degree,
1244 const Standard_Boolean Rational,
1245 const Handle(ShapeCustom_RestrictionParameters)& aParameters)
1248 Returns a new shape with all surfaces, curves and 2D curves which type is BSpline/Bezier or based on the two latter, converted with Degree less than MaxDegree or with a number of spans less then *NbMaxSegment* depending on priority parameter Degree. If this parameter is equal to True then Degree will be increased to the value *GmaxDegree*, otherwise *NbMaxSegments* will be increased to the value *GmaxSegments*. *GmaxDegree* and *GMaxSegments* are the maximum possible degree and the number of spans correspondingly. These values will be used in those cases when an approximation with specified parameters is impossible and one of *GmaxDegree* or *GMaxSegments* is selected depending on priority.
1249 Note that if approximation is impossible with *GMaxDegree*, even then the number of spans can exceed the specified *GMaxSegment*. Rational specifies whether Rational BSpline/Bezier should be converted into polynomial B-Spline.
1250 Also note that the continuity of surfaces in the resulting shape can be less than the given value.
1254 To convert other types of curves and surfaces to BSpline with required parameters it is necessary to use flags from class ShapeCustom_RestrictionParameters, which is just a container of flags.
1255 The following flags define whether a specified-type geometry has been converted to BSpline with the required parameters:
1257 *ConvertBezierSurf, *
1258 *ConvertRevolutionSurf*
1259 *ConvertExtrusionSurf,.*
1260 *ConvertOffsetSurf,*
1262 *ConvertOffsetCurv3d,*
1264 *ConvertOffsetCurv2d,*
1265 *SegmentSurfaceMode*
1267 Parameters *ConvertCurve3d* and *ConvertCurve2d* are responsible for conversion of all types of 3D and 2D curves.
1268 Parameters *ConvertOffsetCurv3d* and *ConvertOffsetCurv2d* are responsible for conversion of offset 3D and 2D curves.
1269 Parameter *SegmentSurfaceMode* defines whether the surface would be approximated within the boundaries of the face lying on this surface.
1271 @subsubsection occt_shg_4_2_4 Conversion of elementary surfaces into surfaces of revolution
1274 ShapeCustom::ConvertToRevolution()
1275 TopoDS_Shape ShapeCustom::ConvertToRevolution(const TopoDS_Shape& S) ;
1278 This method returns a new shape with all elementary periodic surfaces converted to *Geom_SurfaceOfRevolution*. It uses the tool *ShapeCustom_ConvertToRevolution.*
1280 @subsubsection occt_shg_4_2_5 Conversion of elementary surfaces into Bspline surfaces
1283 ShapeCustom::ConvertToBSpline()
1284 TopoDS_Shape ShapeCustom::ConvertToBSpline( const TopoDS_Shape& S,
1285 const Standard_Boolean extrMode,
1286 const Standard_Boolean revolMode,
1287 const Standard_Boolean offsetMode);
1288 This method returns a new shape with all surfaces of linear extrusion, revolution and offset surfaces converted according to flags to Geom_BSplineSurface (with the same parameterization). It uses the tool *ShapeCustom_ConvertToBSpline.*
1290 @subsubsection occt_shg_4_2_6 Getting the history of modification of sub-shapes.
1291 If, in addition to the resulting shape, you want to get the history of modification of sub-shapes you should not use the package methods described above and should use your own code instead:
1292 1. Create a tool that is responsible for the necessary modification.
1293 2. Create the tool BRepTools_Modifier that performs a specified modification in the shape.
1294 3. To get the history and to keep the assembly structure use the method *ShapeCustom::ApplyModifier*.
1297 The general calling syntax for scaling is
1299 TopoDS_Shape scaled_shape = ShapeCustom::ScaleShape(shape, scale);
1302 Note that scale is a real value. You can refine your mapping process by using additional calls to follow shape mapping subshape by subshape. The following code along with pertinent includes can be used:
1306 Standard_Real scale = 100; // for example!
1307 T.SetScale (gp_Pnt (0, 0, 0), scale);
1308 Handle(ShapeCustom_TrsfModification) TM = new
1309 ShapeCustom_TrsfModification(T);
1310 TopTools_DataMapOfShapeShape context;
1311 BRepTools_Modifier MD;
1312 TopoDS_Shape res = ShapeCustom::ApplyModifier (
1313 Shape, TM, context,MD );
1316 The map, called context in our example, contains the history.
1317 Substitutions are made one by one and all shapes are transformed.
1318 To determine what happens to a particular subshape, it is possible to use:
1321 TopoDS_Shape oneres = context.Find (oneshape);
1322 //In case there is a doubt, you can also add:
1323 if (context.IsBound(oneshape)) oneres = context.Find(oneshape);
1324 //You can also sweep the entire data map by using:
1325 TopTools_DataMapIteratorOfDataMapOfShapeShape
1326 //To do this, enter:
1327 for(TopTools_DataMapIteratorOfDataMapOfShapeShape
1328 iter(context);iter(more ();iter.next ()) {
1329 TopoDs_Shape oneshape = iter.key ();
1330 TopoDs_Shape oneres = iter.value ();
1335 @subsubsection occt_shg_4_2_7 Remove internal wires
1337 *ShapeUpgrade_RemoveInternalWires* tool removes internal wires with contour area less than the specified minimal area. It can work with compounds, solids, shells and faces.
1338 If the flag *RemoveFaceMode* is set to TRUE, separate faces or a group of faces with outer wires, which consist only of edges that belong to the removed internal wires, are removed (seam edges are not taken into account). Such faces can be removed only for a sewed shape.
1339 Internal wires can be removed by the methods *Perform*. Both methods *Perform* can not be carried out if the class has not been initialized by the shape. In such case the status of *Perform* is set to FAIL .
1340 The method *Perform* without arguments removes from all faces in the specified shape internal wires whose area is less than the minimal area.
1341 The other method *Perform* has a sequence of shapes as an argument. This sequence can contain faces or wires.
1342 If the sequence of shapes contains wires, only the internal wires are removed.
1343 If the sequence of shapes contains faces, only the internal wires from these faces are removed.
1344 * The status of the performed operation can be obtained using method *Status()*;
1345 * The resulting shape can be obtained using method *GetResult()*.
1347 An example of using this tool is presented in the figures below:
1349 ![](/user_guides/shape_healing/images/shape_healing005.jpg "Source Face")
1350 ![](/user_guides/shape_healing/images/shape_healing006.jpg "Resulting shape")
1352 After the processing three internal wires with contour area less than the specified minimal area have been removed. One internal face has been removed. The outer wire of this face consists of the edges belonging to the removed internal wires and a seam edge.
1353 Two other internal faces have not been removed because their outer wires consist not only of edges belonging to the removed wires.
1355 ![](/user_guides/shape_healing/images/shape_healing007.jpg "Source Face")
1356 ![](/user_guides/shape_healing/images/shape_healing008.jpg "Resulting shape")
1358 After the processing six internal wires with contour area less than the specified minimal area have been removed. Six internal faces have been removed. These faces can be united into groups of faces. Each group of faces has an outer wire consisting only of edges belonging to the removed internal wires. Such groups of faces are also removed.
1360 The example of method application is also given below:
1363 //Initialisation of the class by shape.
1364 Handle(ShapeUpgrade_RemoveInternalWires) aTool = new ShapeUpgrade_RemoveInternalWires(inputShape);
1365 //setting parameters
1366 aTool-MinArea() = aMinArea;
1367 aTool-RemoveFaceMode() = aModeRemoveFaces;
1369 //when method Perform is carried out on separate shapes.
1370 aTool-Perform(aSeqShapes);
1372 //when method Perform is carried out on whole shape.
1374 //check status set after method Perform
1375 if(aTool-Status(ShapeExtend_FAIL) {
1376 cout*Operation failed* ;;\n;;
1380 if(aTool-Status(ShapeExtend_DONE1)) {
1381 const TopTools_SequenceOfShape& aRemovedWires =aTool-RemovedWires();
1382 coutaRemovedWires.Length(); internal wires were removed;;\n;;
1386 if(aTool-Status(ShapeExtend_DONE2)) {
1387 const TopTools_SequenceOfShape& aRemovedFaces =aTool-RemovedFaces();
1388 coutaRemovedFaces.Length(); small faces were removed;;\n;;
1391 //getting result shape
1392 TopoDS_Shape res = aTool-GetResult();
1395 @subsubsection occt_shg_4_2_8 Conversion of surfaces
1397 Class ShapeCustom_Surface allows:
1398 * converting BSpline and Bezier surfaces to the analytical form (using method *ConvertToAnalytical())*
1399 * converting closed B-Spline surfaces to periodic ones.(using method *ConvertToPeriodic*)
1401 To convert surfaces to analytical form this class analyzes the form and the closure of the source surface and defines whether it can be approximated by analytical surface of one of the following types:
1403 * *Geom_SphericalSurface,*
1404 * *Geom_CylindricalSurface,*
1405 * *Geom_ConicalSurface,*
1406 * *Geom_ToroidalSurface*.
1408 The conversion is done only if the new (analytical) surface does not deviate from the source one more than by the given precision.
1411 Handle(Geom_Surface) initSurf;
1412 ShapeCustom_Surface ConvSurf(initSurf);
1413 //conversion to analytical form
1414 Handle(Geom_Surface) newSurf = ConvSurf.ConvertToAnalytical(allowedtol,Standard_False);
1415 //or conversion to a periodic surface
1416 Handle(Geom_Surface) newSurf = ConvSurf.ConvertToPeriodic(Standard_False);
1417 //getting the maximum deviation of the new surface from the initial surface
1418 Standard_Real maxdist = ConvSurf.Gap();
1421 @section occt_shg_5_ Auxiliary tools for repairing, analysis and upgrading
1423 @subsection occt_shg_5_1 Tool for rebuilding shapes
1425 *ShapeBuild_ReShape* rebuilds a shape by making pre-defined substitutions on some of its components. During the first phase, it records requests to replace or remove some individual shapes. For each shape, the last given request is recorded. Requests may be applied as *Oriented* (i.e. only to an item with the same orientation) or not (the orientation of the replacing shape corresponds to that of the original one). Then these requests may be applied to any shape, which may contain one or more of these individual shapes.
1426 This tool has a flag for taking the location of shapes into account (for keeping the structure of assemblies) (*ModeConsiderLocation*). If this mode is equal to Standard_True, the shared shapes with locations will be kept. If this mode is equal to Standard_False, some different shapes will be produced from one shape with different locations after rebuilding. By default, this mode is equal to Standard_False.
1427 To use this tool for the reconstruction of shapes it is necessary to take the following steps:
1428 1. Create this tool and use method *Apply()* for its initialization by the initial shape. Parameter *until* sets the level of shape type and requests are taken into account up to this level only. Sub-shapes of the type standing beyond the *line* set by parameter until will not be rebuilt and no further exploration will be done
1429 2. Replace or remove sub-shapes of the initial shape. Each sub-shape can be replaced by a shape of the same type or by shape containing shapes of that type only (for example, *TopoDS_Edge* can be replaced by *TopoDS_Edge, TopoDS_Wire* or *TopoDS_Compound* containing *TopoDS_Edges*). If an incompatible shape type is encountered, it is ignored and flag FAIL1 is set in Status.
1430 For a sub-shape it is recommended to use method *Apply* before methods *Replace* and *Remove*, because the sub-shape has already been changed for the moment by its previous modifications or modification of its sub-shape (for example *TopoDS_Edge* can be changed by a modification of its *TopoDS_Vertex*, etc.).
1431 3. Use method *Apply* for the initial shape again to get the resulting shape after all modifications have been made.
1432 4. Use method *Apply* to obtain the history of sub-shape modification.
1434 **Note** that in fact class *ShapeBuild_ReShape* is an alias for class *BRepTools_ReShape*. They differ only in queries of statuses in the *ShapeBuild_ReShape* class.
1436 Let us use the tool to get the result shape after modification of sub-shapes of the initial shape:
1439 TopoDS_Shape initialShape…
1440 //creation of a rebuilding tool
1441 Handle(ShapeBuild_ReShape) Context = new ShapeBuild_ReShape.
1443 //next step is optional. It can be used for keeping
1444 //the assembly structure.
1445 Context- ModeConsiderLocation = Standard_True;
1447 //initialization of this tool by the initial shape
1448 Context-Apply(initialShape);
1450 //getting the intermediate result for replacing subshape1 with
1451 //the modified subshape1.
1452 TopoDS_Shape tempshape1 = Context-Apply(subshape1);
1454 //replacing the intermediate shape obtained from subshape1 with the //newsubshape1.
1455 Context-Replace(tempsubshape1,newsubshape1);
1457 //for removing the subshape
1458 TopoDS_Shape tempshape2 = Context-Apply(subshape2);
1459 Context-Remove(tempsubshape2);
1461 //getting the result and the history of modification
1462 TopoDS_Shape resultShape = Context-Apply(initialShape);
1464 //getting the resulting subshape from the subshape1 of the initial //shape.
1465 TopoDS_Shape result_subshape1 = Context-Apply(subshape1);
1468 @subsection occt_shg_5_2 Status definition
1470 *ShapExtend_Status* is used to report the status after executing some methods that can either fail, do something, or do nothing. The status is a set of flags DONEi, FAILi, any combination of them can be set at the same time. For exploring the status, enumeration is used.
1471 The values have the following meaning:
1472 |*OK,* | Nothing is done, everything OK |
1473 |*DONE1,* | Something was done, case 1 |
1474 |*DONE8*, | Something was done, case 8 |
1475 |*DONE*, | Something was done (any of DONE#) |
1476 |*FAIL1*, | The method failed, case 1 |
1477 |*FAIL8*, | The method failed, case 8 |
1478 |*FAIL* | The method failed (any of FAIL# occurred) |
1481 @subsection occt_shg_5_3 Tool representing a wire
1482 Class *ShapeExtend_WireData* provides a data structure necessary to work with the wire as with an ordered list of edges, and that is required for many algorithms. The advantage of this class is that it allows to work with incorrect wires.
1483 The object of the class *ShapeExtend_WireData* can be initialized by *TopoDS_Wire* and converted back to *TopoDS_Wire*.
1484 An edge in the wire is defined by its rank number. Operations of accessing, adding and removing an edge at/to the given rank number are provided. Operations of circular permutation and reversing (both orientations of all edges and the order of edges) are provided on the whole wire as well.
1485 This class also provides a method to check if the edge in the wire is a seam (if the wire lies on a face).
1486 Let us remove edges from the wire and define whether it is seam edge
1489 TopoDS_Wire ini = ..
1490 Handle(ShapeExtend_Wire) asewd = new ShapeExtend_Wire(initwire);
1491 //Removing edge Edge1 from the wire.
1493 Standard_Integer index_edge1 = asewd->Index(Edge1);
1494 asewd.Remove(index_edge1);
1495 //Definition of whether Edge2 is a seam edge
1496 Standard_Integer index_edge2 = asewd->Index(Edge2);
1497 asewd->IsSeam(index_edge2);
1501 @subsection occt_shg_5_4 Tool for exploring shapes
1502 Class *ShapeExtend_Explorer* is intended to explore shapes and convert different representations (list, sequence, compound) of complex shapes. It provides tools for:
1503 * obtaining the type of the shapes in the context of *TopoDS_Compound*,
1504 * exploring shapes in the context of *TopoDS_Compound*,
1505 * converting different representations of shapes (list, sequence, compound).
1507 @subsection occt_shg_5_5 Tool for attaching messages to objects
1508 Class *ShapeExtend_MsgRegistrator* attaches messages to objects (generic Transient or shape). The objects of this class are transmitted to the Shape Healing algorithms so that they could collect messages occurred during shape processing. Messages are added to the Maps (stored as a field) that can be used, for instance, by Data Exchange processors to attach those messages to initial file entities.
1510 Let us send and get a message attached to object:
1513 Handle(ShapeExtend_MsgRegistrator) MessageReg = new ShapeExtend_MsgRegistrator;
1514 //attaches messages to an object (shape or entity)
1516 TopoDS_Shape Shape1…
1517 MessageReg-Send(Shape1,msg,Message_WARNING);
1518 Handle(Standard_Transient) ent ..
1519 MessageReg-Send(ent,msg,Message_WARNING);
1520 //gets messages attached to shape
1521 const ShapeExtend_DataMapOfShapeListOfMsg& msgmap =
1522 MessageReg-MapShape();
1523 if (msgmap.IsBound (Shape1)) {
1524 const Message_ListOfMsg &msglist = msgmap.Find (Shape1);
1525 for (Message_ListIteratorOfListOfMsg iter (msglist);
1526 iter.More(); iter.Next()) {
1527 Message_Msg msg = iter.Value();
1532 @subsection occt_shg_5_6 Tools for performance measurement
1534 Classes *MoniTool_Timer* and *MoniTool_TimerSentry* are used for measuring the performance of a current operation or any part of code, and provide the necessary API. Timers are used for debugging and performance optimizing purposes.
1536 Let us try to use timers in *XSDRAWIGES.cxx* and *IGESBRep_Reader.cxx* to analyse the performance of command *igesbrep*:
1541 #include <MoniTool_Timer.hxx>
1542 #include <MoniTool_TimerSentry.hxx>
1544 MoniTool_Timer::ClearTimers();
1546 MoniTool_TimerSentry MTS("IGES_LoadFile");
1547 Standard_Integer status = Reader.LoadFile(fnom.ToCString());
1550 MoniTool_Timer::DumpTimers(cout);
1556 #include <MoniTool_TimerSentry.hxx>
1558 Standard_Integer nb = theModel->NbEntities();
1560 for (Standard_Integer i=1; i<=nb; i++) {
1561 MoniTool_TimerSentry MTS("IGESToBRep_Transfer");
1565 shape = TransferBRep::ShapeResult (theProc,ent);
1571 The result of *DumpTimer()* after translation of a file is as follows:
1573 | TIMER: *IGES_LoadFile* | Elapsed: 1.0 sec CPU User: 0.9 sec CPU Sys: 0.0 sec hits: 1 |
1574 | TIMER: IGESToBRep_Transfer | Elapsed: 14.5 sec CPU User: 4.4 sec CPU Sys: 0.1 sec hits: 1311 |
1577 @section occt_shg_6 Shape Processing
1579 @subsection occt_shg_6_1 Usage Workflow
1581 The Shape Processing module allows defining and applying the general Shape Processing as a customizable sequence of Shape Healing operators. The customization is implemented via the user-editable resource file, which defines the sequence of operators to be executed and their parameters.
1582 The Shape Processing functionality is implemented with the help of the *XSAlgo* interface. The main function *XSAlgo_AlgoContainer::ProcessShape()* does shape processing with specified tolerances and returns the resulting shape and associated information in the form of *Transient*.
1584 This function is used in the following way:
1587 TopoDS_Shape aShape = …;
1588 Standard_Real Prec = …,
1589 Standard_Real MaxTol = …;
1590 TopoDS_Shape aResult;
1591 Handle(Standard_Transient) info;
1592 TopoDS_Shape aResult = XSAlgo::AlgoContainer()-ProcessShape(aShape,
1593 Prec, MaxTol., *Name of ResourceFile*, *NameSequence*, info );
1596 Let us create a custom sequence of operations:
1598 1. Create a resource file with the name ResourceFile, which includes the following string:
1600 NameSequence.exec.op: MyOper
1602 where *MyOper* is the name of operation.
1604 2. Input a custom parameter for this operation in the resource file, for example:
1606 NameSequence.MyOper.Tolerance: 0.01
1609 where Tolerance is the name of the parameter and 0.01 is its value.
1611 3. Add the following string into *void ShapeProcess_OperLibrary::Init()*:
1614 ShapeProcess::RegisterOperator(;MyOper;,
1615 new ShapeProcess_UOperator(myfunction));
1617 where *myfunction* is a function which implements the operation.
1619 4. Create this function in *ShapeProcess_OperLibrary* as follows:
1621 static Standard_Boolean myfunction (const
1622 Handle(ShapeProcess_Context)& context)
1624 Handle(ShapeProcess_ShapeContext) ctx =
1625 Handle(ShapeProcess_ShapeContext)::DownCast(context);
1626 if(ctx.IsNull()) return Standard_False;
1627 TopoDS_Shape aShape = ctx->Result();
1628 //receive our parameter:
1629 Standard_Real toler;
1630 ctx->GetReal(;Tolerance;, toler);
1633 Now it is possible to make the necessary operations with *aShape* using the received value of parameter *Tolerance* from the resource file.
1636 return Standard_True;
1640 It is possible to define some operations (with their parameters) *MyOper1, MyOper2, MyOper3*, etc. and describe the corresponding functions in *ShapeProcess_OperLibrary*. After that it will be possible to perform the required sequence using the specified name of operations and values of parameters in the resource file.
1642 For example: input of the following string:
1644 NameSequence.exec.op: MyOper1,MyOper3
1646 means that the corresponding functions from *ShapeProcess_OperLibrary* will be performed with the original shape *(aShape)* using parameters defined for *MyOper1* and *MyOper3* in the resource file.
1647 It is necessary to note that these operations will be performed step by step and the result obtained after performing the first operation will be used as the initial shape for the second operation.
1649 @subsection occt_shg_6_2 Operators
1650 **DirectFaces** sets all faces based on indirect surfaces, defined with left-handed coordinate systems as direct faces. This concerns surfaces defined by Axis Placement (Cylinders, etc). Such Axis Placement may be indirect, which is allowed in Cascade, but not allowed in some other systems. This operator reverses indirect placements and recomputes PCurves accordingly.
1651 **SameParameter** is required after calling some other operators, according to the computations they do. Its call is explicit, so each call can be removed according to the operators, which are either called or not afterwards. This mainly concerns splitting operators that can split edges.
1652 The operator applies the computation *SameParameter* which ensures that various representations of each edge (its 3d curve, the pcurve on each of the faces on which it lies) give the same 3D point for the same parameter, within a given tolerance. For each edge coded as ;same parameter;, deviation of curve representation is computed and if the edge tolerance is less than that deviation, the tolerance is increased so that it satisfies the deviation. No geometry modification, only an increase of tolerance is possible. For each edge coded as ;not same parameter; the deviation is computed like in the first case. Then an attempt is made to achieve the edge equality to ;same parameter; by means of modification of 2d curves. If the deviation of this modified edge is less than the original deviation then this edge is returned, otherwise the original edge (with non-modified 2d curves) is returned with an increased (if necessary) tolerance. Computation is done by call to the standard algorithm *BRepLib::SameParameter*.
1653 This operator can be called with the following parameters:
1654 * *Boolean : Force* (optional) - if True, encodes all edges as *not same parameter* then runs the computation. Else, the computation is done only for those edges already coded as *not same parameter*.
1655 * *Real : Tolerance3d* (optional) - if not defined, the local tolerance of each edge is taken for its own computation. Else, this parameter gives the global tolerance for the whole shape.
1656 **BSplineRestriction** is used for conversion of surfaces, curves 2d curves to BSpline surfaces with a specified degree and a specified number of spans.
1657 This operator performs approximations on surfaces, curves and 2d curves with a specified degree, max number of segments, 2d tolerance, 3d tolerance. The specified continuity can be reduced if the approximation with a specified continuity was not done successfully.
1658 This operator can be called with the following parameters:
1659 * *Boolean : SurfaceMode* allows considering the surfaces;
1660 * *Boolean : Curve3dMode* allows considering the 3d curves;
1661 * *Boolean : Curve2dMode* allows considering the 2d curves;
1662 * *Real : Tolerance3d* defines 3d tolerance to be used in computation;
1663 * *Real : Tolerance2d* defines 2d tolerance to be used when computing 2d curves;
1664 * *GeomAbs_Shape (C0 G1 C1 G2 C2 CN) : Continuity3d* is the continuity required in 2d;
1665 * *GeomAbs_Shape (C0 G1 C1 G2 C2 CN) : Continuity2d* is the continuity required in 3d;
1666 * *Integer : RequiredDegree* gives the required degree;
1667 * *Integer : RequiredNbSegments* gives the required number of segments;
1668 * *Boolean : PreferDegree* if true, *RequiredDegree* has a priority, else *RequiredNbSegments* has a priority;
1669 * *Boolean : RationalToPolynomial* serves for conversion of BSplines to polynomial form;
1670 * *Integer : MaxDegree* gives the maximum allowed Degree, if *RequiredDegree* cannot be reached;
1671 * *Integer : MaxNbSegments* gives the maximum allowed NbSegments, if *RequiredNbSegments* cannot be reached;
1673 The following flags allow to manage the conversion of special types of curves or surfaces, in addition to BSpline. They are controlled by *SurfaceMode, Curve3dMode* or *Curve2dMode* respectively. By default, only BSplines and Bezier Geometries are considered.
1674 *Boolean : OffsetSurfaceMode*
1675 *Boolean : LinearExtrusionMode*
1676 *Boolean : RevolutionMode*
1677 *Boolean : OffsetCurve3dMode*
1678 *Boolean : OffsetCurve2dMode*
1679 *Boolean : PlaneMode*
1680 *Boolean : BezierMode*
1681 *Boolean : ConvCurve3dMode*
1682 *Boolean : ConvCurve2dMode*
1683 For each of the Mode parameters listed above, if it is True, the specified geometry is converted to BSpline, otherwise only its basic geometry is checked and converted (if necessary) keeping the original type of geometry (revolution, offset, etc.).
1684 *Boolean :SegmentSurfaceMode* has effect only for Bsplines and Bezier surfaces. When False a surface will be replaced by a Trimmed Surface, else new geometry will be created by splitting the original Bspline or Bezier surface.
1686 **ElementaryToRevolution** converts elementary periodic surfaces to SurfaceOfRevolution.
1688 **SplitAngle** splits surfaces of revolution, cylindrical, toroidal, conical, spherical surfaces in the given shape so that each resulting segment covers not more than the defined number of degrees.
1689 This operator can be called with the following parameters:
1690 * *Real : Angle* - the maximum allowed angle for resulting faces;
1691 * *Real : MaxTolerance* - the maximum tolerance used in computations.
1693 **SurfaceToBSpline** converts some specific types of Surfaces, to BSpline (according to parameters).
1694 This operator can be called with the following parameters:
1695 * *Boolean : LinearExtrusionMode* allows converting surfaces of Linear Extrusion;
1696 * *Boolean : RevolutionMode* allows converting surfaces of Revolution;
1697 * *Boolean : OffsetMode* allows converting Offset Surfaces
1699 **ToBezier** is used for data supported as Bezier only and converts various types of geometries to Bezier
1700 This operator can be called with the following parameters used in computation of conversion :
1701 * *Boolean : SurfaceMode*
1702 * *Boolean : Curve3dMode*
1703 * *Boolean : Curve2dMode*
1704 * *Real : MaxTolerance*
1705 *Boolean : SegmentSurfaceMode* (default is True) has effect only for Bsplines and Bezier surfaces. When False a surface will be replaced by a Trimmed Surface, else new geometry will be created by splitting the original Bspline or Bezier surface.
1707 The following parameters are controlled by *SurfaceMode, Curve3dMode* or *Curve2dMode* (according to the case):
1708 * *Boolean : Line3dMode*
1709 * *Boolean : Circle3dMode*
1710 * *Boolean : Conic3dMode*
1711 * *Boolean : PlaneMode*
1712 * *Boolean : RevolutionMode*
1713 * *Boolean : ExtrusionMode*
1714 * *Boolean : BSplineMode*
1716 **SplitContinuity** splits a shape in order to have each geometry (surface, curve 3d, curve 2d) correspond the given criterion of continuity.
1717 This operator can be called with the following parameters:
1718 * *Real : Tolerance3d*
1719 * *Integer (GeomAbs_Shape ) : CurveContinuity*
1720 * *Integer (GeomAbs_Shape ) : SurfaceContinuity*
1721 * *Real : MaxTolerance*
1724 Because of algorithmic limitations in the operator *BSplineRestriction* (in some particular cases, this operator can produce unexpected C0 geometry), if *SplitContinuity* is called, it is recommended to call it after *BSplineRestriction*.
1725 Continuity Values will be set as *GeomAbs_Shape* (i.e. C0 G1 C1 G2 C2 CN) besides direct integer values (resp. 0 1 2 3 4 5).
1727 **SplitClosedFaces** splits faces, which are closed even if they are not revolutionary or cylindrical, conical, spherical, toroidal. This corresponds to BSpline or Bezier surfaces which can be closed (whether periodic or not), hence they have a seam edge. As a result, no more seam edges remain. The number of points allows to control the minimum count of faces to be produced per input closed face.
1728 This operator can be called with the following parameters:
1729 * *Integer : NbSplitPoints* gives the number of points to use for splitting (the number of intervals produced is *NbSplitPoints+1*);
1730 * *Real : CloseTolerance* tolerance used to determine if a face is closed;
1731 * *Real : MaxTolerance* is used in the computation of splitting.
1733 **FixGaps** must be called when **FixFaceSize** and/or **DropSmallEdges** are called. Using Surface Healing may require an additional call to **BSplineRestriction** to ensure that modified geometries meet the requirements for BSpline.
1734 This operators repairs geometries which contain gaps between edges in wires (always performed) or gaps on faces, controlled by parameter *SurfaceMode*, Gaps on Faces are fixed by using algorithms of Surface Healing
1735 This operator can be called with the following parameters:
1736 * *Real : Tolerance3d* sets the tolerance to reach in 3d. If a gap is less than this value, it is not fixed.
1737 * *Boolean : SurfaceMode* sets the mode of fixing gaps between edges and faces (yes/no) ;
1738 * *Integer : SurfaceAddSpans* sets the number of spans to add to the surface in order to fix gaps ;
1739 * *GeomAbs_Shape (C0 G1 C1 G2 C2 CN) : SurfaceContinuity* sets the minimal continuity of a resulting surface ;
1740 * *Integer : NbIterations* sets the number of iterations
1741 * *Real : Beta* sets the elasticity coefficient for modifying a surface [1-1000] ;
1742 * *Reals : Coeff1 to Coeff6* sets energy coefficients for modifying a surface [0-10000] ;
1743 * *Real : MaxDeflection* sets maximal deflection of surface from an old position.
1745 This operator may change the original geometry. In addition, it is CPU consuming, and it may fail in some cases. Also **FixGaps** can help only when there are gaps obtained as a result of removal of small edges that can be removed by **DropSmallEdges** or **FixFaceSize**.
1747 **FixFaceSize** removes faces, which are small in all directions (spot face) or small in one direction (strip face)
1748 This operator can be called with the parameter *Real : Tolerance*, which sets the minimal dimension, which is used to consider a face, is small enough to be removed.
1750 **DropSmallEdges** drops edges in a wire, and merges them with adjacent edges, when they are smaller than the given value (*Tolerance3d*) and when the topology allows such merging (i.e. same adjacent faces for each of the merged edges). Free (non-shared by adjacent faces) small edges can be also removed in case if they share the same vertex Parameters.
1751 This operator can be called with the parameter *Real : Tolerance3d*, which sets the dimension used to determine if an edge is small.
1753 **FixShape** may be added for fixing invalid shapes. It performs various checks and fixes, according to the modes listed hereafter. Management of a set of fixes can be performed by flags as follows:
1754 if the flag for a fixing tool is set to 0 , it is not performed if set to 1 , it is performed in any case if not set, or set to -1 , for each shape to be applied on, a check is done to evaluate whether a fix is needed. The fix is performed if the check is positive
1755 By default, they are not set, i.e. evaluated for each individual shape.
1756 This operator can be called with the following parameters:
1757 * *Real : Tolerance3d* sets basic tolerance used for fixing;
1758 * *Real : MaxTolerance3d* sets maximum allowed value for the resulting tolerance;
1759 * *Real : MinTolerance3d* sets minimum allowed value for the resulting tolerance.
1760 * *Boolean : FixFreeShellMode*
1761 * *Boolean : FixFreeFaceMode*
1762 * *Boolean : FixFreeWireMode*
1763 * *Boolean : FixSameParameterMode*
1764 * *Boolean : FixSolidMode*
1765 * *Boolean : FixShellMode*
1766 * *Boolean : FixFaceMode*
1767 * *Boolean : FixWireMode*
1768 * *Boolean : FixOrientationMode*
1769 * *Boolean : FixMissingSeamMode*
1770 * *Boolean : FixSmallAreaWireMode*
1771 * *Boolean (not checked) : ModifyTopologyMode* specifies the mode for modifying topology. Should be False (default) for shapes with shells and can be True for free faces.
1772 * *Boolean (not checked) : ModifyGeometryMode* specifies the mode for modifying geometry. Should be False if geometry is to be kept and True if it can be modified.
1773 * *Boolean (not checked) : ClosedWireMode* specifies the mode for wires. Should be True for wires on faces and False for free wires.
1774 * *Boolean (not checked) : PreferencePCurveMode (not used)* specifies the preference of 3d or 2d representations for an edge
1775 * *Boolean : FixReorderMode*
1776 * *Boolean : FixSmallMode*
1777 * *Boolean : FixConnectedMode*
1778 * *Boolean : FixEdgeCurvesMode*
1779 * *Boolean : FixDegeneratedMode*
1780 * *Boolean : FixLackingMode*
1781 * *Boolean : FixSelfIntersectionMode*
1782 * *Boolean : FixGaps3dMode*
1783 * *Boolean : FixGaps2dMode*
1784 * *Boolean : FixReversed2dMode*
1785 * *Boolean : FixRemovePCurveMode*
1786 * *Boolean : FixRemoveCurve3dMode*
1787 * *Boolean : FixAddPCurveMode*
1788 * *Boolean : FixAddCurve3dMode*
1789 * *Boolean : FixSeamMode*
1790 * *Boolean : FixShiftedMode*
1791 * *Boolean : FixEdgeSameParameterMode*
1792 * *Boolean : FixSelfIntersectingEdgeMode*
1793 * *Boolean : FixIntersectingEdgesMode*
1794 * *Boolean : FixNonAdjacentIntersectingEdgesMode*
1796 **SplitClosedEdges** handles closed edges i.e. edges with one vertex. Such edges are not supported in some receiving systems. This operator splits topologically closed edges (i.e. edges having one vertex) into two edges. Degenerated edges and edges with a size of less than Tolerance are not processed.
1798 @section occt_shg_7_ Messaging mechanism
1800 Various messages about modification, warnings and fails can be generated in the process of shape fixing or upgrade. The messaging mechanism allows generating messages, which will be sent to the chosen target medium a file or the screen. The messages may report failures and/or warnings or provide information on events such as analysis, fixing or upgrade of shapes.
1802 @subsection occt_shg_7_2 Message Gravity
1803 Enumeration *Message_Gravity* is used for defining message gravity.
1804 It provides the following message statuses:
1805 * *Message_FAIL* - the message reports a fail;
1806 * *Message_WARNING* - the message reports a warning;
1807 * *Message_INFO* - the message supplies information.
1809 @subsection occt_shg_7_3 Tool for loading a message file into memory
1810 Class *Message_MsgFile* allows defining messages by loading a custom message file into memory. It is necessary to create a custom message file before loading it into memory, as its path will be used as the argument to load it. Each message in the message file is identified by a key. The user can get the text content of the message by specifying the message key.
1812 Format of the message file
1813 --------------------------
1814 The message file is an ASCII file, which defines a set of messages. Each line of the file must have a length of less than 255 characters.
1815 All lines in the file starting with the exclamation sign (perhaps preceded by spaces and/or tabs) are considered as comments and are ignored.
1816 A message file may contain several messages. Each message is identified by its key (string).
1817 Each line in the file starting with the *dot* character (perhaps preceded by spaces and/or tabs) defines the key. The key is a string starting with a symbol placed after the dot and ending with the symbol preceding the ending of the newline character *\n*.
1818 All the lines in the file after the key and before the next keyword (and which are not comments) define the message for that key. If the message consists of several lines, the message string will contain newline symbols *\n* between each line (but not at the end).
1819 The following example illustrates the structure of a message file:
1822 !This is a sample message file
1823 !------------------------------
1824 !Messages for ShapeAnalysis package
1827 Your message string goes here
1831 !End of message file
1834 Loading the message file
1835 ------------------------
1836 A custom file can be loaded into memory using the method *Message_MsgFile::LoadFile*, taking as an argument the path to your file as in the example below:
1838 Standard_CString MsgFilePath = ;(path)/sample.file;;
1839 Message_MsgFile::LoadFile (MsgFilePath);
1842 @subsection occt_shg_7_4 Tool for managing filling messages
1844 The class *Message_Msg* allows using the message file loaded as a template. This class provides a tool for preparing the message, filling it with parameters, storing and outputting to the default trace file.
1845 A message is created from a key: this key identifies the message to be created in the message file. The text of the message is taken from the loaded message file (class *Message_MsgFile* is used).
1846 The text of the message can contain places for parameters, which are to be filled by the proper values when the message is prepared. These parameters can be of the following types:
1847 * string - coded in the text as *%s*,
1848 * integer - coded in the text as *%d*,
1849 * real - coded in the text as *%f*.
1850 The parameter fields are filled by the message text by calling the corresponding methods *AddInteger, AddReal* and *AddString*. Both the original text of the message and the input text with substituted parameters are stored in the object. The prepared and filled message can be output to the default trace file. The text of the message (either original or filled) can be also obtained.
1852 Message_Msg msg01 (;SampleKeyword;);
1853 //Creates the message msg01, identified in the file by the keyword SampleKeyword
1854 msg1.AddInteger (73);
1855 msg1.AddString (;SampleFile;);
1856 //fills out the code areas
1860 @subsection occt_shg_7_5 Tool for managing trace files
1862 Class *Message_TraceFile* is intended to manage the trace file (or stream) for outputting messages and the current trace level. Trace level is an integer number, which is used when messages are sent. Generally, 0 means minimum, 0 various levels. If the current trace level is lower than the level of the message it is not output to the trace file. The trace level is to be managed and used by the users.
1863 There are two ways of using trace files:
1864 * define an object of *Message_TraceFile*, with its own definition (file name or cout, trace level), and use it where it is defined,
1865 * use the default trace file (file name or cout, trace level), usable from anywhere.
1866 Use the constructor method to define the target file and the level of the messages as in the example below:
1868 Message_TraceFile myTF
1869 (tracelevel, *tracefile.log*, Standard_False);
1871 The parameters are as follows:
1872 * *tracelevel* is a Standard_Integer and modifies the level of messages. It has the following values and semantics:
1873 + 0: gives general information such as the start and end of process;
1874 + 1: gives exceptions raised and fail messages;
1875 + 2: gives the same information as 1 plus warning messages.
1876 * *filename* is the string containing the path to the log file.
1877 The Boolean set to False will rewrite the existing file. When set to True, new messages will be appended to the existing file.
1879 A new default log file can be added using method *SetDefault* with the same arguments as in the constructor.
1880 The default trace level can be changed by using method *SetDefLevel*. In this way, the information received in the log file is modified.
1881 It is possible to close the log file and set the default trace output to the screen display instead of the log file using the method *SetDefault* without any arguments.
1884 @section occt_211336372_61271129 Appendix B
1885 @subsection occt_211336372_612711291 Examples of use
1886 @subsubsection occt_211336372_6127112911 ShapeAnalysis_Edge and ShapeFix_Edge
1898 ![](/user_guides/shape_healing/images/shape_healing_image011.png)
1901 </table> In this example an edge is shown where the maximum deviation between the 3D curve and 2D curve P1 is greater than the edge tolerance.
1904 ShapeAnalysis_Edge sae;
1905 TopoDS_Face face = ...;
1906 TopoDS_Wire wire = ...;
1907 Standard_Real precision = 1e-04;
1909 Standard_Real maxdev;
1910 if (sae.CheckSameParameter (edge, maxdev)) {
1911 cout*Incorrect SameParameter flag*endl;
1912 cout*Maximum deviation *maxdev *, tolerance *
1913 BRep_Tool::Tolerance(edge)endl;
1914 // Maximum deviation between pcurve and
1915 // 3D curve is greater than tolerance
1916 sfe.FixSameParameter();
1917 cout*New tolerance *BRep_Tool::Tolerance(edge)endl;
1918 // Tolerance is increased to englobe the deviation
1932 ![](/user_guides/shape_healing/images/shape_healing_image012.png)
1935 </table> The result is an increased edge tolerance:
1937 @subsubsection occt_211336372_6127112912 ShapeAnalysis_Wire and ShapeFix_Wire
1938 This wire is first analyzed to check that:
1939 * the edges are correctly oriented
1940 * there are no edges that are too short and
1941 * that there are no intersecting adjacent edges.
1955 ![](/user_guides/shape_healing/images/shape_healing_image013.png)
1961 ShapeAnalysis_Edge sae;
1962 TopoDS_Face face = ...;
1963 TopoDS_Wire wire = ...;
1964 Standard_Real precision = 1e-04;
1966 Standard_Real maxdev;
1967 if (sae.CheckSameParameter (edge, maxdev)) {
1968 cout<<“Incorrect SameParameter flag”<<endl;
1969 cout<<“Maximum deviation “<<maxdev<< “, tolerance “
1970 <<BRep_Tool::Tolerance(edge)<<endl;
1971 // Maximum deviation between pcurve and
1972 // 3D curve is greater than tolerance
1973 sfe.FixSameParameter();
1974 cout<<“New tolerance “<<BRep_Tool::Tolerance(edge)<<endl;
1975 // Tolerance is increased to englobe the deviation
1980 ShapeAnalysis_Wire saw (wire, face, precision);
1981 ShapeFix_Wire sfw (wire, face, precision);
1982 if (saw.CheckOrder()) {
1983 cout*Some edges in the wire need to be reordered*endl;
1984 // Two edges are incorrectly oriented
1986 cout*Reordering is done*endl;
1988 // their orientation is corrected
1989 if (saw.CheckSmall (precision)) {
1990 cout*Wire contains edge(s) shorter than *precisionendl;
1991 // An edge that is shorter than the given
1992 // tolerance is found
1993 Standard_Boolean LockVertex = Standard_True;
1994 if (sfw.FixSmall (LockVertex, precision)) {
1995 cout*Edges shorter than *precision* have been removed*
1997 //The edge is removed
2000 if (saw.CheckSelfIntersection()) {
2001 cout*Wire has self-intersecting or intersecting
2002 adjacent edges*endl;
2003 // Two intersecting adjacent edges are found
2004 if (sfw.FixSelfIntersection()) {
2005 cout*Wire was slightly self-intersecting. Repaired*endl;
2006 // The edges are cut at the intersection point so
2007 // that they no longer intersect
2011 ![](/user_guides/shape_healing/images/shape_healing_image014.png)
2012 @subsubsection occt_211336372_6127112913 MoniTool_Timer
2013 Using timers in XSDRAWIGES.cxx and IGESBRep_Reader.cxx for analysis performance command ;igesbrep;:
2017 #include MoniTool_Timer.hxx
2018 #include MoniTool_TimerSentry.hxx
2020 MoniTool_Timer::ClearTimers();
2022 MoniTool_TimerSentry MTS(;IGES_LoadFile;);
2023 Standard_Integer status = Reader.LoadFile(fnom.ToCString());
2026 MoniTool_Timer::DumpTimers(cout);
2032 #include MoniTool_TimerSentry.hxx
2034 Standard_Integer nb = theModel-NbEntities();
2036 for (Standard_Integer i=1; i=nb; i++) {
2037 MoniTool_TimerSentry MTS(;IGESToBRep_Transfer;);
2041 shape = TransferBRep::ShapeResult (theProc,ent);
2047 DumpTimer() after translation file: