This commit contains all the remained parts needed for initial integration of
OpenSubdiv into Blender's subdivision surface code. Includes both GPU and CPU
backends which works in the following way:
- When SubSurf modifier is the last in the modifiers stack then GPU pipeline
of OpenSubdiv is used, making viewport performance as fast as possible.
This also requires graphscard with GLSL 1.5 support. If this requirement is
not met, then no GPU pipeline is used at all.
- If SubSurf is not a last modifier or if DerivesMesh is being evaluated for
rendering then CPU limit evaluation API from OpenSubdiv is used. This only
replaces the legacy evaluation code from CCGSubSurf_legacy, but keeps CCG
structures exactly the same as they used to be for ages now.
This integration is fully covered with ifdef and not enabled by default
because there are several TODOs to be solved first:
- Face varying data interpolation is not really cleanly implemented for GPU
in OpenSubdiv 3.0. It is also not implemented for limit evaluation API.
This basically means we'll have really hard time supporting UVs.
- Limit evaluation only works with adaptivly subdivided meshes so far, which
basically means all the points of CCG are pushed to the limit. This gives
different result from old code.
- There are some serious optimizations possible on the topology refiner
creation, which would speed up initial OpenSubdiv mesh creation.
- There are some hardcoded asumptions in the GPU and DerivedMesh areas which
could be generalized.
That's something where Antony and Campbell can help, making it so the code
is structured in a way which is reusable by all planned viewport projects.
- There are also some workarounds in the dependency graph to make sure OpenGL
buffers are only freed from the main thread.
Those who'll be wanting to make experiments with this code should grab dev
branch (NOT master) from
https://github.com/Nazg-Gul/OpenSubdiv/tree/dev
There are some patches applied in there which we're working on on getting
into upstream.
ATIs.
This is actually a test to see if this can be enabled on ATI cards.
According to various sources, newer ATI cards supporting GLSL 3.0
support gl_ClippingDistance in shaders, which is the forward compatible
way to do custom clipping.
This fix will bind 6 additional varying variables on ATIs, which may
lead to some shaders not compiling due to limiting out of those
variables, or to performance degradation. Also I do not have an ATI
handy to test.
Having those in mind, this commit may well be reverted later.
Clipping planes are usually 4 (6 is for cube clipping), but making
shaders depend on viewport state is really bad, and would lead to
recompilation, so I took the worst case here to avoid that.
Hopefully driver does some optimization there.
Clipping border causes a software fallback on ATIs. We have disabled it
in that case but from minor digging on the net seems like Intels support
this, so enable.
code is still unused, but the intention is to use this to solve the double sided
lighting problem on NVidia, and to make the materials work on OpenGL ES 2.0
eventually.
The code works and matches the fixed function lighting pretty much exactly, but
still needs optimizations. The actual integration in object draw will be
committed later when more fixing & testing, there's lots of different combinations
and unclear OpenGL state here.
* Shadow color now usable in the BGE
* Simplified the shadow panel while "Blender Game" renderer is active
* Added variance shadow maps for the BGE
* Buffered shadows on sun lamps in the BGE (orthographic)
* Light textures in the BGE
