1. Check whether the mesh satisfies the required angular deflection has been amended. Namely normals (to the surface) in the ends of any not "frontier" link are made collinear (with the given angular tolerance).
2. New parameters AngleInterior and DeflectionInterior have been added in IMeshTools_Parameters structure.
3. In case of thin long faces with internal edges, add points of internal edges to control parameters using grabParamsOfInternalEdges() in order to avoid aberrations on its ends. Disable addition of parameters from boundary edges in case of BSpline surface. Deviation can be controlled through the deflection parameter.
4. Grab parameters from edges in case if there is just a single interval on BSpline surface along U and V direction.
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.
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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.
Modification of algorithm in order to prevent violation of angular and curvature deflection condition for smooth intervals of curve.
Modification of algorithm for calculation of maximal deflection in command crvtpoints, crvpoints (CR25649)
Elementary bug fixing in algorithm GCPnts_UniformDeflection.gxx
Modification of test cases in order to set new reference parameters of shape triangulations
Some tests:
bugs modalg_2 bug397
mesh standard_incmesh C7, V3
mesh standard_incmesh_parallel C7, V3
mesh standard_mesh C7, V3
mesh standard_shading V3
were modified by TODO with reference bug 27226, because some problems in meshing algorithm (package BRepMesh) were discovered when tessellation of edges was changed. These problems cannot be solved by modification of GCPnts_TangentialDeflection algorithm. New issue #27226 was created, see bugtracker for details.
Correction of test data
Test case for issue #27108
Modification of algorithm for improving performance
Correction of test cases
Fix compilation error on Linux
Adding test command for this fix
meshPolygon: simplify source polygon by splitting it onto parts without glued edges and loops
Check surrounded triangles during final cleaning of mesh
Correct polygon on frontier edges
Modified test cases in group mesh according to new behavior
