--- Operating System, Graphics card ---
OS: Ubuntu Release 12.04 (precise) 64-bit, Kernel Linux 3.2.0-35-generic, GNOME 3.4.2
GFX: nVidia FXQuadro 4500 512mb
--- Blender version with error, and version that worked ---
ERROR: Blender 2.65a SVN53473
WORKED: 2.64a r51232
--- Short description of error ---
When using OpenGL Rendering the active viewport (click on the little camera button), the edge of object looks jerky in the rendered image. This didn't occur in any previous version.
--- Steps for others to reproduce the error (preferably based on attached .blend file) ---
Please refer to the attached images (same .blend file rendered in both 2.64a and 2.65a with OpenGL rendering). The one made with 2.65a SVN53473 (2.65a.jpg) looks jerky.
Description
Event Timeline
Error caused by alpha premul changes. Seems OpenGL render still uses transparent sky which is not supported now. Will investigate this.
transparent alpha is useful for project paint 'Quick Edit', reverting rev53570,
Sergey: does some premul conversion need to be done here instead?, this wasnt a problem in previous releases.
Campbell, if you need transparent alpha, color should be set to black. If you want horizon color the most proper way is to make background opaque. In previous releases it wasn't a problem because for image it wasn't clear whether it's straight or premul alpha and it only kind of worked in this case because was displaying premul alpha on a screen configured for straight alpha.
If transparent background is needed for quick edit, make it so background is set to transparent black. But if other color is used for background, alpha shall be 1.0. Otherwise you'll screw up the whole color management.
Commited another fix (rev53588) which should work for both texture painting and opengl render. Basically:
- OpenGL render and sequencer's opengl preview will now reflect scene's Alpha Mode
- Quick Edit will use OpenGL with transparent alpha mode
In my tests seems to be working fine, if some issue will be discovered, i'll reopen the report :)