The goal of this PR is to remove the per face, NDC space
tracing for shadow maps.
This requires custom occluder extrapolation but in return
removes quite a lot of complexity in other areas, namely:
- No more per face transform before the tracing
- No more per face jittering (fix#119565)
- No more frustum padding (increased maximum precision)
- Better use of 32bit precision shadow map
- Fix#121343
This improve softness at relatively low step count (default 6
is better) and reduces light leaking at very low sample
count (sharper). It makes it more intuitive now that
higher sample count is smoother.
Pull Request: https://projects.blender.org/blender/blender/pulls/121317