0031461: Mesh - Add possibility to force the meshing of the shape BRepMesh: Add new mesh parameter *AllowQualityDecrease* which affects the criteria used for checking of the consistency of the existing mesh to new meshing parameters. So if set to true it will force the meshing of the shape if current deflection strongly vary from the new one, no matter in which side. BRepTools::Clean: Keep triangulation on non-geometric shapes (faces with no surface or edges with no curves).

0030497: [REGRESSION] Mesh - wrong Poly_Polygon3D within local selection of located shape The previous code has a condition to avoid processing the same faces if the face has a location. The similar condition should be applied during the edges processing. If not doing this, in the previous implementation, IMeshData_Edge instances are created for all edges(even located), but edges of faces located are not filled with curves. As a result we had wrong local selection of edges. Limit addition of edges to data model by ones with unique TShape and location using edges map already available in BRepMesh_ShapeVisitor.

0026106: BRepMesh - revision of data model Removed tight connections between data structures, auxiliary tools and algorithms in order to create extensible solution, easy for maintenance and improvements; Code is separated on several functional units responsible for specific operation for the sake of simplification of debugging and readability; Introduced new data structures enabling possibility to manipulate discrete model of particular entity (edge, wire, face) in order to perform computations locally instead of processing an entire model. The workflow of updated component can be divided on six parts: * Creation of model data structure: source TopoDS_Shape passed to algorithm is analyzed and exploded on faces and edges. For each topological entity corresponding reflection is created in data model. Note that underlying algorithms use data model as input and access it via common interface which allows user to create custom data model with necessary dependencies between particular entities; * Discretize edges 3D & 2D curves: 3D curve as well as associated set of 2D curves of each model edge is discretized in order to create coherent skeleton used as a base in faces meshing process. In case if some edge of source shape already contains polygonal data which suites specified parameters, it is extracted from shape and stored to the model as is. Each edge is processed separately, adjacency is not taken into account; * Heal discrete model: source TopoDS_Shape can contain problems, such as open-wire or self-intersections, introduced during design, exchange or modification of model. In addition, some problems like self-intersections can be introduced by roughly discretized edges. This stage is responsible for analysis of discrete model in order to detect and repair faced problems or refuse model’s part for further processing in case if problem cannot be solved; * Preprocess discrete model: defines actions specific for implemented approach to be performed before meshing of faces. By default, iterates over model faces and checks consistency of existing triangulations. Cleans topological faces and its adjacent edges from polygonal data in case of inconsistency or marks face of discrete model as not required for computation; * Discretize faces: represents core part performing mesh generation for particular face based on 2D discrete data related to processing face. Caches polygonal data associated with face’s edges in data model for further processing and stores generated mesh to TopoDS_Face; * Postprocess discrete model: defines actions specific for implemented approach to be performed after meshing of faces. By default, stores polygonal data obtained on previous stage to TopoDS_Edge objects of source model. Component is now spread over IMeshData, IMeshTools, BRepMeshData and BRepMesh units. <!break> 1. Extend "tricheck" DRAW-command in order to find degenerated triangles. 2. Class BRepMesh_FastDiscret::Parameters has been declared as deprecated. 3. NURBS range splitter: do not split intervals without necessity. Intervals are split only in case if it is impossible to compute normals directly on intervals. 4. Default value of IMeshTools_Parameters::MinSize has been changed. New value is equal to 0.1*Deflection. 5. Correction of test scripts: 1) perf mesh bug27119: requested deflection is increased from 1e-6 to 1e-5 to keep reasonable performance (but still reproducing original issue) 2) bugs mesh bug26692_1, 2: make snapshot of triangulation instead of wireframe (irrelevant) Correction in upgrade guide.