aedd5f2837
This PR implements the background blurring for studiolight/lookdev HDRIs. The visual appearance matches EEVEE-Classic closely. **Technical details** - LOD0 is skipped as the regular background color can be used. The regular background color is blended towards LOD1. - Volume probe is mixed in to remove baked in artifacts in the higher LODs. Pull Request: https://projects.blender.org/blender/blender/pulls/119872