Generated normals can be opposed to face one, needs winding flipping in this case
Closed, ResolvedPublic

Description

System Information
Windows 7 64-bit
nVidia GeForce GT 430

Blender Version
Broken: 2.72 6b2952c Branch:testbuild, mont29 build from GraphicAll.org

Short description of error
Set Split Normals modifiers causes mesh to render double-sided faces improperly, "Double-sided" checkbox does not affect anything at all.
Also,

Exact steps for others to reproduce the error
Just render attached file with Cycles, or Blender Internal.

Details

Differential Revisions
D1814: Add mesh utilities to flip all/some polygons.
Type
To Do
Yury Baranov (oguretz) updated the task description. (Show Details)
Yury Baranov (oguretz) raised the priority of this task from to Needs Triage.
Yury Baranov (oguretz) set Type to Bug.
Bastien Montagne (mont29) triaged this task as Normal priority.

Hmm, in fact, there is no bug here. Issue is, generated 'vertex' normals are opposed to face one. Double sided cannot do anything useful in this case.

I’ll check this, should be possible to flip winding of faces which normals are opposed to generated one e.g.

Bastien Montagne (mont29) changed Type from Bug to To Do.Nov 6 2014, 9:01 PM
Bastien Montagne (mont29) renamed this task from Set Split Normals modifiers causes mesh to render double-sided faces improperly to Generated normals can be opposed to face one, needs winding flipping in this case.Nov 6 2014, 9:04 PM

I suggest to make modified normals + doublesided option to work like this:

Bastien Montagne (mont29) closed this task as Resolved.Feb 28 2016, 4:28 PM

grr, typo in commit message, but fixed by rBe3841c91f93270! :P