2nd derivatives aren't used within Blender but all
logic branches end up with checking for it. This PR
removes the 2nd derivatives from the code so we
can skip this test.
Pull Request: https://projects.blender.org/blender/blender/pulls/135745
Blender already had its own copy of OpenSubDiv containing some local fixes
and code-style. This code still used gl-calls. This PR updates the calls
to use GPU module. This allows us to use OpenSubDiv to be usable on other
backends as well.
This PR was tested on OpenGL, Vulkan and Metal. Metal can be enabled,
but Vulkan requires some API changes to work with loose geometry.
# Considerations
**ShaderCreateInfo**
intern/opensubdiv now requires access to GPU module. This to create buffers
in the correct context and trigger correct dispatches. ShaderCreateInfo is used
to construct the shader for cross compilation to Metal/Vulkan. However opensubdiv
shader caching structures are still used.
**Vertex buffers vs storage buffers**
Implementation tries to keep as close to the original OSD implementation. If
they used storage buffers for data, we will use GPUStorageBuf. If it uses vertex
buffers, we will use gpu::VertBuf.
**Evaluator const**
The evaluator cannot be const anymore as the GPU module API only allows
updating SSBOs when constructing. API could be improved to support updating
SSBOs.
Current implementation has a change to use reads out of bounds when constructing
SSBOs. An API change is in the planning to remove this issue. This will be fixed in
an upcoming PR. We wanted to land this PR as the visibility of the issue is not
common and multiple other changes rely on this PR to land.
Pull Request: https://projects.blender.org/blender/blender/pulls/135296
Along with the 4.1 libraries upgrade, we are bumping the clang-format
version from 8-12 to 17. This affects quite a few files.
If not already the case, you may consider pointing your IDE to the
clang-format binary bundled with the Blender precompiled libraries.
This was caused by the use of a reserved keyword macro that is not
directly used but causes an error on some compiler.
Change the occurences to not match the macros.
Coarse meshes with high polycount would show as corrupted when GPU
subdivision is used with AMD cards This was caused by the OpenSubdiv
library not taking `GL_MAX_COMPUTE_WORK_GROUP_COUNT` into account when
dispatching computes. AMD drivers tend to set the limit lower than
NVidia ones (2^16 for the former, and 2^32 for the latter, at least
on my machine).
This moves the `GLComputeEvaluator` from the OpenSubdiv library into
`intern/opensubdiv` and modifies it to compute a dispatch size in a
similar way as for the draw code: we split the dispatch size into a 2
dimensional value based on `GL_MAX_COMPUTE_WORK_GROUP_COUNT` and
manually compute an index in the shader.
We could have patched the OpenSubdiv library and sent the fix upstream
(which can still be done), however, moving it to our side allows us to
better control the `GLComputeEvaluator` and in the future remove some
redundant work that it does compared to Blender (see T94644) and
probably prepare the ground for Vulkan support. As a matter of fact,
this patch also removes the OpenGL initialization that OpenSubdiv would
do here. This removal is not related to the bug fix, but necessary to not
have to copy more files/code over.
Differential Revision: https://developer.blender.org/D14131
