different order of face vertices indexes between 2.76b and 2.77a #48444

New Issue

Jakub Uhlik · 2016-05-15T20:44:18+02:00

Jakub Uhlik commented

2016-05-15 20:44:18 +02:00

System Information
Mac OS X

Blender Version
Broken: 2.77a
Worked: 2.76b

Short description of error
different order of face vertices causing problems exporting meshes

Exact steps for others to reproduce the error
list face vertices in both blender versions, lists won't be the same, eg:

l = [p.vertices[:] for p in me.polygons]

hello, i am writing exporter for Maxwell Render (https://github.com/uhlik/blendmaxwell). maxwell has feature of rendertime subdivision modifier. exactly same scene and same exporter revision creates same mesh visually, but because of different order of face vertices indexes, mesh from 2.77a with subdivision modifier refuses to render with error: "An edge connecting two vertices was specified more than once. It's likely that an incident face was flipped". the only difference is order of triangle vertices indexes returned from simple loop like the one above. was the behavior of polygon.vertices changed? haven't seen anything in release notes. or it is a bug? might cause problems for other exporters as well..

**System Information** Mac OS X **Blender Version** Broken: 2.77a Worked: 2.76b **Short description of error** different order of face vertices causing problems exporting meshes **Exact steps for others to reproduce the error** list face vertices in both blender versions, lists won't be the same, eg: ``` l = [p.vertices[:] for p in me.polygons] ``` hello, i am writing exporter for Maxwell Render (https://github.com/uhlik/blendmaxwell). maxwell has feature of rendertime subdivision modifier. exactly same scene and same exporter revision creates same mesh visually, but because of different order of face vertices indexes, mesh from 2.77a with subdivision modifier refuses to render with error: "An edge connecting two vertices was specified more than once. It's likely that an incident face was flipped". the only difference is order of triangle vertices indexes returned from simple loop like the one above. was the behavior of polygon.vertices changed? haven't seen anything in release notes. or it is a bug? might cause problems for other exporters as well..

Jakub Uhlik commented

2016-05-15 20:44:18 +02:00

Changed status to: 'Open'

Jakub Uhlik commented

2016-05-15 20:44:18 +02:00

Added subscriber: @JakubUhlik

Bastien Montagne commented

2016-05-15 20:59:19 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2016-05-15 20:59:19 +02:00

Cannot reproduce that here, tested same file in 2.76b, 2.77a and current master and get exact same result. Please attach a .blend showing the issue.

Jakub Uhlik commented

2016-05-16 05:35:21 +02:00

here is a blend. run script.a.blend

here is a blend. run script.[a.blend](https://archive.blender.org/developer/F312368/a.blend)

Bastien Montagne commented

2016-05-16 10:39:45 +02:00

Added subscriber: @ideasman42

Bastien Montagne commented

2016-05-16 10:39:45 +02:00

Ok, so this has nothing to do with py API, it’s just the triangulate BMesh operator that changed somehow… @ideasman42 may know better here, but I cannot see anything wrong in results of 2.76 or 2.77, order may change, but triangles and their winding remains the same.

Campbell Barton commented

2016-05-16 11:47:59 +02:00

Changed status from 'Open' to: 'Archived'

Campbell Barton closed this issue

2016-05-16 11:47:59 +02:00

Campbell Barton self-assigned this 2016-05-16 11:47:59 +02:00

Campbell Barton commented

2016-05-16 11:47:59 +02:00

Triangulation has had some tweaks since 2.76, unless the geometry is invalid. This isn't considered a bug.

Adding the following lines to the Text in a.blend shows there are no duplicate edges.

edges = [tuple(sorted(e.vertices)) for e in me.edges]
print(edges)
print(len(edges), len(set(edges)))

closing.

Triangulation has had some tweaks since 2.76, unless the geometry is invalid. This isn't considered a bug. Adding the following lines to the `Text` in `a.blend` shows there are no duplicate edges. ``` edges = [tuple(sorted(e.vertices)) for e in me.edges] print(edges) print(len(edges), len(set(edges))) ``` closing.

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different order of face vertices indexes between 2.76b and 2.77a #48444