New Clay Render system

[DavidBluecame]

Major changes to the Clay Render system to make it more flexible and powerful, as requested in several feature requests in the bug tracker:

• Clay pass but keeping transparency/translucency http://www.yafaray.org/node/541
• clay render with original relief maps http://www.yafaray.org/node/600
• Clay render with Oren Nayar shading http://www.yafaray.org/node/602
• Material off clay render http://www.yafaray.org/node/599
• Clay render default color http://www.yafaray.org/node/618

The old system of a "temporary" ClayMat material has been overriden and no longer works. The new system consists in altering the properties of the materials in the export process, so we can keep some of their properties and do a more fine grained control.

• Default Clay color is now 0.5,0.5,0.5 (Midle-Grey), it can be changed (as before)
• Default Clay shader is diffuse shader Oren-Nayar sigma=0.5. The Oren Nayar shader can be disabled to use the standard diffuse shader.
• Option to keep transpareny in glass/transparent objects during Clay Render (also keeps transparent textures). It does not work yet in Blend materials.
• Option to keep bump/normal maps during Clay Render.
• Per-material option to exclude a certain material from the Clay Render. If a material is excluded, it shows normally during the Clay Render. For now this works only partially in Blend materials: if you want to exclude a Blend material you can, but you also need to exclude all the individual materials that make the blended material.

I hope you find this useful.

Changes to be committed: modified: io/yaf_export.py modified: io/yaf_material.py modified: io/yaf_object.py modified: prop/yaf_material.py modified: prop/yaf_scene.py modified: ui/properties_yaf_general_settings.py modified: ui/properties_yaf_material.py

[DavidBluecame]

Hello,

Some example images here: http://www.yafaray.org/community/forum/viewtopic.php?p=31023#p31023

Hope you find it useful.

[DavidBluecame]

Hello,

I've made an experimental build for Blender 2.74 / Windows 7/8.1 64bits including this fix. Please see:

http://www.yafaray.org/community/forum/viewtopic.php?p=31038#p31038

Please test it and let us know if it works for you.

[DavidBluecame]

I'm preparing a more complex system with many more mappings for more types of materials and the new Clay Render integrated with them, so I'm closing this pull request for now and I will open another pull request in the future for the entire new system.