0030442: Mesh - broken triangulation on pipe shape
Scale down min size parameter for NURBS taking into account its U and V resolution in order to prevent comparison of 2d parameters with 3d value involved in filtering process.
0032422: Mesh - Weird rendering
0029641: Mesher produce 'bad' result for extruded spline with given deviation coefficient
Added method BRepMesh_NURBSRangeSplitter::getUndefinedInterval() intended to compute checkpoint parameters for those NURBS surfaces which have no intervals at all. In this case number of poles is used to produce artificial regular grid which can be refined further. Add at least one midpoint for surfaces with one interval and only two poles.
Added BRepMesh_ExtrusionRangeSplitter and BRepMesh_UndefinedRangeSplitter derivatives from BRepMesh_NURBSRangeSplitter intended to handle special cases of extrusion surfaces and general surfaces with undefined parameters.
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.
1) BRepMesh_FastDiscretFace.cxx:
- exclude planes from procedure of inserting internal points.
- localize declaration of the container aNewVertices in each method where it is needed.
- correct the logic of the method insertInternalVerticesOther, so that to separate the processes of removing extra points and addition of new points in different cycles, thus making the code more clear and in addition stable.
- insert useful output of intermediate mesh to a file in control() method for debug purposes (with definition DEBUG_MESH).
2) Add global functions MeshTest_DrawTriangles and MeshTest_DrawLinks to draw mesh data in debug session.
3) BRepMesh_FastDiscret:
- in the method Add calculations of deflections have been simplified for non-relative mode.
- replace the attribute MinDist with Deflection in EdgeAttributes structure. Correct its computation so that later to store this value as deflection of the polygon.
4) Make protection against exception in the method BRepMesh_Delaun::addTriangle() when an added triangle creates a third connection of a mesh edge.
5) BRepMesh_EdgeTessellator.cxx, BRepMesh_EdgeTessellationExtractor.cxx: use Geom2dAdaptor_Curve in order to use b-spline cache while computing value on a curve.
6) In BndLib_Box2dCurve::PerformBSpline, avoid creating new b-spline in case of requested parameter range differ from natural bounds insignificantly.
7) In GeomAdaptor classes, postpone building of cache till the time of its actual usage. So, creation of an adapter to compute intervals of continuity does not lead to creation of internal cache.
8) In the methods BRepAdaptor_Curve::Bezier and BSpline do not call Transformed() if transformation is identity.
9) In the classes Geom_BSplineCurve, Geom_BSplineSurface, Geom_BezierCurve, Geom_BezierSurface, Geom2d_BSplineCurve, Geom2d_BezierCurve change the method Pole() to return the point by const reference.
10) In CPnts_AbscissaPoint.cxx, compute derivative by D1 instead of DN to make use of b-spline cache.
11) Change test cases to actual state:
- Number of triangles/nodes can grow due to more accurate work with deflection of edges. Now the edge is tessellated using its own tolerance instead of maximal tolerance of all shapes in the face.
- Accept new numbers of mesh errors (free links, free nodes) for really bad shapes.
- Correct the test "bugs/mesh/bug25612" to produce stable result.
- Disable redundant checks in test cases bug25378* (lower limit for computation time).
- Speed up iso-lines computation for offset of bspline surfaces. For that use adaptor instead of original surface in evaluator of approximation.
- Add output of polylines for debug of insertInternalVerticesOther().
Reference data in test case bugs\moddata_2\bug453_3 have been changed to be close to expected theoretical values. This makes the test give stable result on different platforms.
- Added function checkprops, set default tolerance parameter to 1.0e-4
- Using "area" instead of "square".
- Options "-equal\notequal" isn't used together with "-s" in blend and offset test cases.
- Correct regressions/differences/improvements and CPU problem (set props tolerance to 0.1)
- Corrected test cases to use checkprops proc.
- Correct image difference
- Updated TODOs in test cases.
- Updated test cases to get correct images of result shape
