Blender Git Loki

Wheee!

Initial commit for supporting rendering particles directly as
volume density. It works by looking up how many particles are
within a specified radius of the currently shaded point and using
that to calculate density (which is used just as any other
measure of density would be).

http://mke3.net/blender/devel/rendering/volumetrics/smoke_test01.mov
http://mke3.net/blender/devel/rendering/volumetrics/smoke_test01.blend

Right now it's an early implementation, just to see that it can
work - it may end up changing quite a bit. Currently, it's just a
single switch on the volume material - it looks up all particles
in the scene for density at the current shaded point in world
space (so the volume region must enclose the particles in order
to render them.

This will probably change - one idea I have is to make the
particle density estimation a procedural texture with options for:
* the object and particle system to use
* the origin of the co-ordinate system, i.e. object center, world
space, etc.

This would allow you in a sense, to instance particle systems for
render - you only need to bake one particle system, but you can
render it anywhere.

Anyway, plenty of work to do here, firstly on getting a nice
density evaluation with falloff etc...