[Bf-committers] True Volumetrics Update 3

[echelon at infomail.upr.edu.cu]

Hello!

   After spending the whole weekend hunting a nasty memory bug regarding
integration of volumetric with blender render code (you know: fix
something and broke other) now that i fix it, the volumetric from
procedural stack and node shader tree is relatively stable and do
"correct" intersections between other volumetrics or any objects (like
Ztransp), also volumetrics are reflected in objects with reflectance
and well refracted to.

Essentially I added 2 new files to blender code : volumetric.c and
volumetric.h into render forlders, in this files all the heavy stuff are
done, in the rest of the code I only make function calls, this way, once
the volumetrics get well integrated, further changes and improvements only
afects those files only, the interface remains the same.

Considering that blender is subject to major recode and if everything goes
well and volumetrics gets finally integrated this would be for 2.50 or
later, all the integration stuff is subject to changes to (but I hope not
to much).