Maniphest T67109

Broken rendering of mesh (ngon filling)
Closed, Resolved
Actions

Assigned To
Campbell Barton (campbellbarton)
Authored By
Miro Horváth (dreamak)
Jul 17 2019, 9:42 AM
Tags
  • BF Blender
  • Modeling
Subscribers
Campbell Barton (campbellbarton)
Clément Foucault (fclem)
Miro Horváth (dreamak)
Philipp Oeser (lichtwerk)
Vyacheslav (hitrpr)
Tokens
"Like" token, awarded by hitrpr.

Description

System Information
Operating system: W10
Graphics card: nvidia970

Blender Version
Broken: (example: 2.80, RC1)
Worked: never, I can see this problem even in 2.79b

Short description of error
Screenshot below shows the problem. If I move any of the vertices of the mesh or change object's origin it got fixed.

Exact steps for others to reproduce the error

repro.blend598 KBDownload

Revisions and Commits

rB Blender
rBe31a1c6fd3e1 Fix T67109: n-gon tessellation error with co-linear edges

Related Objects

Mentioned In
rBfa1d47069288: GTest: test cases for polyfill2d bug T67109
T68172: Solidify modifier display glitches when use a curve (curve/ngon filling)

Event Timeline

Miro Horváth (dreamak) created this task.Jul 17 2019, 9:42 AM
Philipp Oeser (lichtwerk) added subscribers: Clément Foucault (fclem), Campbell Barton (campbellbarton), Philipp Oeser (lichtwerk).EditedJul 17 2019, 11:01 AM

Not exactly sure how this mesh has been created?, but somehow the filling of this ngon has a problem.
might be a numerical problem in this very specific case that leads to a borked winding/normal.
mesh seems to be valid otherwise (mesh.validate() returns False)
also tried re-sorting mesh indices, but that doesnt seem to have an effect...

other solutions:

  • flip normals solves the problem
  • delete only faces, fill again solves the problem as well

wouldnt consider this a bug, but maybe @Clément Foucault (fclem) or @Campbell Barton (campbellbarton) could shed some light on the exact reasons why this happens...

Vyacheslav (hitrpr) added a subscriber: Vyacheslav (hitrpr).Jul 27 2019, 12:55 AM

It is strange that glitch appear only when mesh is on the certain positions.
Only in the certain x-positions Blender tries to connect vertices wrong. Y positiom changes nothing.

repro1.blend571 KBDownload

Philipp Oeser (lichtwerk) assigned this task to Campbell Barton (campbellbarton).Aug 2 2019, 12:39 PM
Philipp Oeser (lichtwerk) lowered the priority of this task from 90 to 80.

Will assign to @Campbell Barton (campbellbarton) for the time being...

Philipp Oeser (lichtwerk) renamed this task from Broken rendering of mesh to Broken rendering of mesh (ngon filling).Aug 5 2019, 9:30 AM
Philipp Oeser (lichtwerk) added a project: Modeling.Aug 5 2019, 9:38 AM
Philipp Oeser (lichtwerk) mentioned this in T68172: Solidify modifier display glitches when use a curve (curve/ngon filling).Aug 5 2019, 9:43 AM
Campbell Barton (campbellbarton) lowered the priority of this task from 80 to 50.Aug 5 2019, 11:45 AM
Campbell Barton (campbellbarton) changed the task status from Unknown Status to Resolved by committing rBe31a1c6fd3e1: Fix T67109: n-gon tessellation error with co-linear edges.Aug 5 2019, 2:45 PM
Campbell Barton (campbellbarton) added a commit: rBe31a1c6fd3e1: Fix T67109: n-gon tessellation error with co-linear edges.
Campbell Barton (campbellbarton) mentioned this in rBfa1d47069288: GTest: test cases for polyfill2d bug T67109.
Vyacheslav (hitrpr) awarded a token.Aug 5 2019, 11:15 PM