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|ID||Project||Category||View Status||Date Submitted||Last Update|
|0023837||Open CASCADE||[OCCT] OCCT:Mesh||public||2013-03-19 15:49||2018-10-15 17:03|
|Target Version||Fixed in Version|
|Summary||0023837: BRepMesh shouldn't trust the SameParameter flag|
|Description||Description of this bug is taken from issue 0023184 (post by MSV):|
The check of cross-face errors should not be eliminated. It is well defined (see MeshTest_CheckTopology.hxx):
//! - cross face errors. It is a situation when a point on a common
//! boundary between two faces has different 3d coordinates on each
//! triangulation. The error is reported if the distance is greater
//! than a deflection written in triangulations.
I would change this definition, in order to compare distance between nodes of triangulation with the real distance between curves representations (value returned by the DRAW command computetolerance), rather than with mesh deflection.
As applied to this problem, we checked with OAN and found out that the common edges in the shape have improper samerange/sameparameter flag, because the command computetolerance returns the value about 0.02, while the edge's tolerance is 2e-5. BRepMesh trusts the flag SameParameter, and when a new point is inserted in some polygon on triangulation, its insertion into another polygon with the same parameter gives wrong point.
So, the solution would be to stop trusting the SameParameter flag (recompute the flag locally).
|Steps To Reproduce||mesh standard_incmesh W7|
|Tags||No tags attached.|
|Test case number|
|2013-03-19 15:49||oan||New Issue|
|2013-03-19 15:49||oan||Assigned To||=> oan|
|2013-03-19 15:49||oan||Relationship added||related to 0023184|
|2016-10-17 11:31||oan||Relationship added||related to 0026106|
|2018-10-15 17:03||oan||Relationship added||related to 0025134|
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