AgX exhibited some banding-like artifacts that were due to being
approximated with a 3D LUT. This commit resolves that by increasing
the LUT resolution enough to mitigate the artifacts and make them
unnoticeable.
Additionally:
- The previous LUTs were written in a space-inefficient way, using
e.g. "0.000000" instead of "0". The new LUTs are written more
efficiently, avoiding quite as dramatic a file size increase as
usually accompanies 3D LUT resolution increases.
- The previous LUTs included output values greater than 1.0, which was
both incorrect for a tone mapper, and also pointless since Blender
immediately clips them anyway. The new LUTs clip to 1.0. This also
allows the more efficient writing to squeeze even more space savings
out of the LUTs.
- The previous inverse AgX LUT contained NaNs. Those have been
replaced with 0.0 in the new inverse LUT.
Note that due to discrepancies between the LUTs previously provided
to Blender and the AgX scripts that were later published, the color
transform in these LUTs are slightly different. But they are close, and
equivalently good.
Pull Request: https://projects.blender.org/blender/blender/pulls/113253
e26d287520
