View Issue Details

IDProjectCategoryView StatusLast Update
0022893CommunityOCCT:Meshpublic2012-11-09 10:12
Reporterszy Assigned Tomkv 
Status closedResolutionno change required 
Product Version6.5.2 
Target Version6.5.3Fixed in Version6.5.3 
Summary0022893: Possible regression in tesselation algorithm of OCCT6.5.2
Description[OCC Forum] Problem with version 6.5.2 (Francesco Argese <>) -

I have noted that version 6.5.2 of OpenCascade has introduced some problems displaying the model taken from here [1]. I cannot attach it here because its size (6.80 MB) is bigger than the maximum allowed size on this forum (2 MB); if you give me an email address that could accept its size I'll send you there.

In particular, if you see it using front view of Import/Export app and zooming it with the new version the surface doesn't appear right while with the 6.5.1 and with other CAD softwares it appears right.

I have the same problem with my app written with OpenCascade that uses another visualization library so probably the problem could be in the BRepMesh triangulator.

Thanks in advance and happy new year!
Francesco Argese

The problem is reproduced on OCCT6.5.2 and not reproduced on OCCT6.5.1.
Steps To Reproducepload ALL
igesread thread_22534_boing777.igs s *
checkshape s
## Ok
vdisplay s
TagsNo tags attached.
Test case numberchl 934 P6

Attached Files

  • Post_22534.7z (1,195,950 bytes)
  • lateral_face.brep (292,696 bytes)
  • boing.JPG (26,393 bytes)


related to 0022778 closedbugmaster Community Bug in BRepMesh 



2012-01-10 17:08


Post_22534.7z (1,195,950 bytes)


2012-01-10 17:39


lateral_face.brep (292,696 bytes)


2012-01-10 17:40


boing.JPG (26,393 bytes)


2012-01-10 17:42

manager   ~0019076

The problem becomes more visible on the lateral face of the model. See the attached separate face (lateral_face.brep - s_59) and a picture of the boing.


2012-01-16 12:42

developer   ~0019135

Dear Bugmaster,

This problem is not reproduced in current version of trank.(It looks fix of bug22781 solved this problem). Number of triangles in problem face for bug22778 is good(2148 triangles; 1135 nodes; max deflection 6.7388607894560643e-005)

Please create the new test case for current problem and close the bug.


2012-02-07 11:26

administrator   ~0019421

Problem is not reproduced on current OCCT

Issue History

Date Modified Username Field Change
2012-01-10 17:08 szy New Issue
2012-01-10 17:08 szy Assigned To => msv
2012-01-10 17:08 szy File Added: Post_22534.7z
2012-01-10 17:39 szy File Added: lateral_face.brep
2012-01-10 17:40 szy File Added: boing.JPG
2012-01-10 17:42 szy Note Added: 0019076
2012-01-14 08:24 abv Relationship added related to 0022778
2012-01-16 10:47 pdn Assigned To msv => epa
2012-01-16 12:06 abv Status new => assigned
2012-01-16 12:42 epa Note Added: 0019135
2012-01-16 12:42 epa Assigned To epa => bugmaster
2012-01-16 12:42 epa Status assigned => feedback
2012-01-20 15:16 bugmaster Assigned To bugmaster => mkv
2012-01-30 10:18 apn Test case number => chl 934 P6
2012-02-07 11:26 bugmaster Note Added: 0019421
2012-02-07 11:26 bugmaster Status feedback => closed
2012-02-07 11:26 bugmaster Resolution open => no change required
2012-02-07 11:31 bugmaster Fixed in Version => 6.5.3
2012-11-09 10:12 abv Changeset attached => occt master 3492f422
2012-11-09 10:12 abv Category OCCT:Modeling Algorithms => OCCT:Mesh