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0025042Community[OCCT] OCCT:Meshpublic2014-07-01 11:262018-11-11 12:00
Vico Liang 
bugmaster 
normalmajor 
verifiedfixed 
Win7WindowsWin7
[OCCT] 6.7.1 
[OCCT] 7.4.0* 
bugs/mesh/bug25042
0025042: Cone Meshing: Missing two connecting edges.
BRepMesh_IncrementalMesh will generated invalid mesh. The result is shown in the attached image file MeshingBugOfCone.png.
1. Create a cone solid.
BRepPrimAPI_MakeCone aMakeCone(200, 0, 500);

2. Clean Mesh.
BRepTools::Clean(aMakeCone.Shape());

3. Generate incremental mesh:
BRepMesh_IncrementalMesh aMeshAlgo(aMakeCone.Shape(), 0.2, Standard_True, 0.2, Standard_True);

4. Display mesh with MeshVS.
No tags attached.
has duplicate 0027798closed bugmaster Community Bad or degenerated triangles should be avoided (e.g for Cone meshing) 
png MeshingBugOfCone.png (51,649) 2014-07-01 11:26
https://tracker.dev.opencascade.org/
png OCC671.png (7,556) 2014-10-16 14:50
https://tracker.dev.opencascade.org/
png ConeMeshBug671.png (7,565) 2014-10-17 18:01
https://tracker.dev.opencascade.org/
png zoom_degenerative.png (11,862) 2014-11-05 15:42
https://tracker.dev.opencascade.org/
png mesh_parametric_1.png (46,069) 2014-11-05 15:43
https://tracker.dev.opencascade.org/
Issue History
2014-07-01 11:26Vico LiangNew Issue
2014-07-01 11:26Vico LiangAssigned To => oan
2014-07-01 11:26Vico LiangFile Added: MeshingBugOfCone.png
2014-09-12 12:32abvTarget Version => 6.8.0
2014-10-16 14:50oanNote Added: 0033212
2014-10-16 14:50oanAssigned Tooan => Vico Liang
2014-10-16 14:50oanStatusnew => feedback
2014-10-16 14:50oanFile Added: OCC671.png
2014-10-16 14:51oanNote Edited: 0033212bug_revision_view_page.php?bugnote_id=33212#r8402
2014-10-17 18:01Vico LiangFile Added: ConeMeshBug671.png
2014-10-17 18:07Vico LiangNote Added: 0033274
2014-10-31 03:36Vico LiangNote Added: 0033917
2014-10-31 09:52abvAssigned ToVico Liang => oan
2014-10-31 09:52abvStatusfeedback => assigned
2014-10-31 09:53abvTarget Version6.8.0 => 7.1.0
2014-11-05 10:52oanNote Added: 0034020
2014-11-05 11:39oanStatusassigned => feedback
2014-11-05 11:40oanAssigned Tooan => Vico Liang
2014-11-05 14:23Vico LiangNote Added: 0034040
2014-11-05 14:23Vico LiangAssigned ToVico Liang =>
2014-11-05 14:24Vico LiangAssigned To => oan
2014-11-05 15:42oanNote Added: 0034051
2014-11-05 15:42oanFile Added: zoom_degenerative.png
2014-11-05 15:43oanFile Added: mesh_parametric_1.png
2014-11-05 15:44oanAssigned Tooan => Vico Liang
2014-11-08 06:49Vico LiangAssigned ToVico Liang => oan
2014-11-08 06:57Vico LiangNote Added: 0034173
2014-11-25 20:50oanStatusfeedback => assigned
2016-08-22 11:07oanRelationship addedhas duplicate 0027798
2016-11-03 17:38abvTarget Version7.1.0 => 7.2.0
2017-07-20 12:43oanTarget Version7.2.0 => 7.3.0
2018-02-25 21:09abvTarget Version7.3.0 => 7.4.0*
2018-11-07 16:33oanRelationship addedrelated to 0028379
2018-11-07 17:01oanNote Added: 0080854
2018-11-07 17:01oanAssigned Tooan => nbv
2018-11-07 17:01oanStatusassigned => feedback
2018-11-08 09:59gitNote Added: 0080910
2018-11-08 11:18nbvNote Added: 0080924
2018-11-08 11:18nbvAssigned Tonbv => msv
2018-11-08 11:18nbvStatusfeedback => resolved
2018-11-08 16:35msvNote Added: 0080971
2018-11-08 16:35msvAssigned Tomsv => bugmaster
2018-11-08 16:35msvStatusresolved => reviewed
2018-11-08 17:26bugmasterNote Added: 0080976
2018-11-08 17:26bugmasterStatusreviewed => tested
2018-11-08 17:27bugmasterTest case number => bugs/mesh/bug25042
2018-11-09 13:38gitNote Added: 0080996
2018-11-11 11:52bugmasterChangeset attached => occt master e2f8fe44
2018-11-11 11:52bugmasterStatustested => verified
2018-11-11 11:52bugmasterResolutionopen => fixed
2018-11-11 12:00gitNote Added: 0081020

Notes
(0033212)
oan   
2014-10-16 14:50   
(edited on: 2014-10-16 14:51)
Dear Vico Liang,

I can not reproduce reported problem neither on OCCT 6.7.1 nor on current master using Draw (see attached screenshot OCC671.png).

Please provide resulting shape containing broken mesh as well as description of the way how you display it.

(0033274)
Vico Liang   
2014-10-17 18:07   
Dear OAN,

Please have a try with following case, the bug is still there.

BRepPrimAPI_MakeCone aMakeCone(150, 0, 500);
BRepMesh_IncrementalMesh aMeshAlgo(aMakeCone.Shape(), 0.2, Standard_True, 0.2, Standard_True);

See picture ConeMeshBug671.png.
(0033917)
Vico Liang   
2014-10-31 03:36   
Dear OAN,

I don't have permission to assign this to the developer, please help me do it.
(0034020)
oan   
2014-11-05 10:52   
Hi Vico Liang,

to whom you expect to assign this issue?
(0034040)
Vico Liang   
2014-11-05 14:23   
Hi OAN,

Please have a look at the bug again, it can be reproduced with new data input in my previous feedback.
(0034051)
oan   
2014-11-05 15:42   
Dear Vico Liang,

Yes, I see the point - I have just tried to reproduce the bug using current master branch. In fact, mesh is consistent, tricheck command says nothing that means mesh is connected and does not contain lacks. Looking more precisely you can see that reported problem represents case with degenerative triangle (see the attached screenshot zoom_degenerative.png).

Such thing is possible due to transformations introduced during passing from parametric space to 3D (screenshot mesh_parametric_1.png describes this process).

Nevertheless, such result is not quite fine for cone and it will be fixed in order of priority. Be sure we are tracking this issue and it will not be lost.

You also welcome to make your contribution to OCCT and participate in the development of the fix for this bug. We will be glad to see you as a community developer.

With best regards,
Oleg.
(0034173)
Vico Liang   
2014-11-08 06:57   
Dear Oleg,

I understand the problem and there is actually a degenerated triangle. So the generated triangulation is consistent. To keep this issue for further bug fix, you might be the best candidate for this issue.

Thank you,
Vico
(0080854)
oan   
2018-11-07 17:01   
Should be fixed in context of #28379.
Could you please check and create test case.
(0080910)
git   
2018-11-08 09:59   
Branch CR25042 has been created by nbv.

SHA-1: 64c5800618793374cee22d416f9a9f61c328a165


Detailed log of new commits:

Author: nbv
Date: Thu Nov 8 09:57:17 2018 +0300

    0025042: Cone Meshing: Missing two connecting edges.
    
    Adding test case for the issue.
    The problem has been fixed by the patch #28379.
(0080924)
nbv   
2018-11-08 11:18   
Dear Mikhail,

Please review the branch CR25042.

Test results are here:

Windows: http://jenkins-test-12.nnov.opencascade.com/view/CR25042-master_NBV/view/TESTING/job/CR25042-master_NBV-OCCT-Windows-64-VC14-opt-test-restart/HTML_20Report/ [^]

Linux: http://jenkins-test-12.nnov.opencascade.com/view/CR25042-master_NBV/view/TESTING/job/CR25042-master_NBV-OCCT-Debian80-64-opt-test-restart/HTML_20Report/ [^]
(0080971)
msv   
2018-11-08 16:35   
Reviewed.
(0080976)
bugmaster   
2018-11-08 17:26   
Adding test case
(0080996)
git   
2018-11-09 13:38   
Branch CR25042 has been updated forcibly by oan.

SHA-1: feec0b893e877e314f68a6c03fb90a78649df359
(0081020)
git   
2018-11-11 12:00   
Branch CR25042 has been deleted by inv.

SHA-1: feec0b893e877e314f68a6c03fb90a78649df359