Blender Git Loki

Render Cache: irradiance cache:

* increase truncated SVD epsilon to avoid avoid large color changes when
interpolating between near colinear points.
* added neighbour clamping. it doesn't seem to help much and make things
a bit slower at the moment, but hopefully can be used to get better
distribution later.

Main remaining causes of artifacts seem to be:

* even 32x32 (1024) samples can still be noisy leading to low frequency
noise after interpolation
* borders between tiles can have discontinuities. this is mostly visible
in combination with the above problem, i.e. if the result is splotchy
it will have a different splotches in the next tile.
* very small features may be missed still, leading to missing shadows in
some cases or even stippled patterns instead if they are detected part
of the time, neighbour clamping helps somewhat here.