Implement OpenVDB support

boberfly / GafferCycles

Cycles for Gaffer

BSD 3-Clause "New" or "Revised" License

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Implement OpenVDB support #16

Closed boberfly closed 4 years ago

boberfly commented 5 years ago

Currently Cycles mainline doesn't support OpenVDB, however there was a Google Summer of Code in 2018 in which it has been implemented, however no one has merged it quite yet.

https://developer.blender.org/rB9f4e5581d18899d665d61e93ae7c6933c5a3e770

I have a test branch of this here: https://github.com/boberfly/cycles/tree/vdbTest

There was some patching to do and I discarded the blender addon code as it was for 2.8 and Cycles standalone still targets 2.79, but this is not needed for the purposes of GafferCycles.

boberfly commented 4 years ago

Progress Screenshot_20191027_135337 Still can't seem to make it actually render past the bounds here (I believe Cycles creates an outer geometry layer for optimisation, this is what is seen here afaik).

boberfly commented 4 years ago

Screenshot_20191028_074931

boberfly commented 4 years ago

A few issues with the GSoC 2018 patch:

the built-in volume re-mesher for optimisation likes to run each time there's a simple change to the scene, hopefully we can fix this in Cycles code.
This is quarter res wdas_cloud.vdb and using the full res one the time to first pixel is crazy, maybe we can just get OpenVDB to generate the mesh instead.
Increasing density looks like the isovalue of the mesh needs to be increased with this adjustment, otherwise the outer optimisation mesh is apparent and the voxels can be seen...
Cuda/OpenCL devices aren't working yet

boberfly commented 4 years ago

Closing this as VDB volumes have been implemented in Cycles mainline and render in GafferCycles.