There was a bug due to non-aligned struct in the DNA that prevented us
to increase the size of the userdef light array.
Since the studio lights are now presets and stored in external files,
there is no need to keep backward compatibility with theses lights.
Remove the old array and create a new one.
Add blue tint light for specular.
Shadow focus let the user choose how hard are is the shadows transition.
Harder shadow transition can be used for stylistic effects or more uniform
shading.
Make shadow orientation respect the same orientation as the studio light
(view from +Y direction aka. front view). Make the default shadow direction
more similar to the default light position (the default light object, not
the default studio lighting).
Texture paint code was retrieving the evaluated mesh from the
original object, which isn't supposed to happen, so the cached
mesh isn't properly cleaned up by Edit Mode toggle.
Note that am not sure that is actually needed, since switching to that
mode does not actually use any eval data, it's only needed during init
of first stroke... But in doubt, that won't hurt to have it here anyway.
This reverts commit 3f31c28a02.
Gives issues zooming, could be resolved but it mostly worked OK before,
and it's not a priority to spend time on, so leave as is for now.
Now used the original dist instead, since using the distance between
the camera and the views offset may seem random from the users POV.
This addresses strange behavior noticed in T56934.
* Move the curvature computation to the cavity pass: One can argue it's not
the best performance wise (it gets a tiny perf pernalty if it is done
alone without the ssao), but it make the code cleaner and reduce
considerably the number of shader variation possible.
* Lower shader variation to 2^8 instead of 2^12
