Initial work by Clément Foucault with contributions from Dalai Felinto
(mainly per-collection engine settings logic, and depsgraph iterator placeholder).
This makes Blender require OpenGL 3.3. Which means Intel graphic card
and OSX will break. Disable CLAY_ENGINE in CMake in those cases.
This is a prototype render engine intended to help the design of real
render engines. This is mainly an engine with enphasis in matcap and
ambient occlusion.
Implemented Features
--------------------
* Clay Render Engine, following the new API, to be used as reference for
future engines
* A more complete Matcap customization with more options
* Per-Collection render engine settings
* New Ground Truth AO - not enabled
Missing Features
----------------
* Finish object edit mode
- Fix shaders to use new matrix
- Fix artifacts when edge does off screen
- Fix depth issue
- Selection sillhouette
- Mesh wires
- Use mesh normals (for higher quality matcap)
- Non-Mesh objects drawing
- Widget drawing
- Performance issues
* Finish mesh edit mode
- Derived-Mesh-less edit mode API (mesh_rende.c)
* General edit mode
- Per-collection edit mode settings
* General engines
- Per-collection engine settings
(they are their, but they still need to be flushed by depsgraph, and
used by the drawing code)
