F12 rendering creates artifacts on geometry created with Screw Modifier #37691

New Issue

Voyager Voyager · 2013-12-03T15:05:35+01:00

Voyager Voyager commented

2013-12-03 15:05:35 +01:00

System Information
Windows 7, 64bit, GeForce GT 555M

Blender Version
Broken: Blender Blender 2.69 r60995

Short description of error
There is incostency between viewport shading and rendering where viewport shading is correct whilst rendering creates artifacts on geometry created with Screw Modifier.

Exact steps for others to reproduce the error
Attached image shows differences between viewport shading (on the left side) and F12 rendering. I suppose it may be the problem with normals. Disabling Smooth Shading in Screw Modifier solves the problem.cycles_screw_bug.blend

**System Information** Windows 7, 64bit, GeForce GT 555M **Blender Version** Broken: Blender Blender 2.69 r60995 **Short description of error** There is incostency between viewport shading and rendering where viewport shading is correct whilst rendering creates artifacts on geometry created with Screw Modifier. **Exact steps for others to reproduce the error** Attached image shows differences between viewport shading (on the left side) and F12 rendering. I suppose it may be the problem with normals. Disabling Smooth Shading in Screw Modifier solves the problem.[cycles_screw_bug.blend](https://archive.blender.org/developer/F36194/cycles_screw_bug.blend) ![cycles_screw_bug.jpg](https://archive.blender.org/developer/F36195/cycles_screw_bug.jpg)

Voyager Voyager commented

2013-12-03 15:05:35 +01:00

Changed status to: 'Open'

Brecht Van Lommel was assigned by Voyager Voyager

2013-12-03 15:05:35 +01:00

Voyager Voyager commented

2013-12-03 15:05:35 +01:00

Added subscriber: @voyagercgi

Brecht Van Lommel commented

2013-12-08 00:47:19 +01:00

Even in the viewport there is a black spot in the middle of this mesh, something wrong with the modifier probably.

Voyager Voyager commented

2013-12-08 13:31:21 +01:00

Yes, IMO it's not the problem of Cycles itself but screw modifier. After applying the modifier the problem still exist but when you go to edit mode and again to object mode Cycles has no problem at all. As I stated before the culprit is probably not calculated properly normals.

Brecht Van Lommel was unassigned by Campbell Barton

2013-12-18 20:24:43 +01:00

Campbell Barton self-assigned this 2013-12-18 20:24:43 +01:00

Campbell Barton commented

2013-12-18 20:24:43 +01:00

Added subscriber: @brecht