If the object is manifold and the camera is in the shadow side, we can
use the depth fail method to fix the inverted shadow glitch.
Unfortunately this does not really work for non-manifold.
Implementation details:
We try to be as efficient as we can, we precompute camera near plane
projected into 2D shadow space so we can test for intersection with the
shadow boundbox easily.
As the intersection test is done in 2D it's pretty fast.
Unfortunately, this means the shadow bounds are all aligned to the same
space and are not the smallest bound we could extract.
The Studio lights are now loaded from disk. The location is
`datafiles/studiolights` they need to be JPG for now. JPG cannot store
HDRI color range but they are clamped inside the Workbench
engine for speed reason. I didn't select JP2K as it might not be
enabled.
Users can add upto 20 HDRI files. This limitation is inside the
RNA_space.c Currently the icons are calculated when you first open the
selection box for the HDRI's. We could add them to a background
rendering later.
I added 2 test files a sky texture rendered in Cycles and an HDRI from
cloud.blender.org.
