[Bf-cycles] volumetric-mlt-spectral status

[storm]

As maybe some interested people can notice, recently i posting updates
in longer intervals. The reason is i trying to solve perfect mirror and
transparent surfaces weights. I was wrongly tink that it is trivial to
fix (trying to focusing to only flat
diffusion/glossy_with_non_zero_roughness), postpone that, and only
recently notice that pinhole perspective camera have same issue, and my
current code making wrong boost to light tracer samples (started from
light), making final image worse then PT and even worse then w/o MIS at
all.

So, i really MUST to solve that, as even w/o any mirror /transparent
material, any scene will have issues.

The good news, is that when i make MIS weight offset manually (some ugly
hackish black magic around debug_0 value ), result is somewhat
comparable with what i seen Maxwell test scene, i mean not
speed/quality, but overall feeling how noise converging near hard
places. 

Currrently i trying to play with (L|D)S*DD*DE notation, better study how
it related to path pdf, and other related things. Have some ideas how to
skip unrelated bounce pdf from final, but far from real results.

Damn Maxwell yellow juice material make me pissed off. (cannot resist
and have download demo maxwell packet, trying basic "pyramid on floor"
scenes) For a minute have strong feeling to fire disassembler to see how
it do that ^^. But it is dark side way, and i doubt there is something
unknown used, as arnold or many other, that is just good polished
implenentation of well known algorithms.