Materialize repeated opacities for compatibility with multiple splatting implementations#600
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Signed-off-by: Matthew Cong <mcong@nvidia.com>
fwilliams
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Apr 13, 2026
swahtz
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Apr 13, 2026
Signed-off-by: Matthew Cong <mcong@nvidia.com>
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Currently, we unsqueeze and expand the opacities (following the optimization in #451) creating a non-contiguous view. However, the image space mGPU rasterization and world space rasterization implementations require contiguous expanded opacities. This PR changes opacities to always be expanded for consistent behavior across multiple splatting implementations. Note that we can't simply call
contiguous()in the specific operator impl because the shared autograd code caches the opacities for the backwards pass.This undoes the optimization in #451 and results in a small (~0.5%) decrease in performance in the single GPU case. However, this is outweighed by the corresponding speedups in the mGPU and world space case due to one fewer allocation and more efficient paging.