Finally making some progress, using new Vray 1.2 It's possible to use proxies with mograph thus allowing vast numbers of polygon objects to be rendered. Image below is made up of thousands of transparent spheres, thus creating a volumetric effect like fire where each sphere is additive so when they clump or overlap it becomes brighter shifting the color up thru the hues to the point of white, which is how light behaves opposed to say paint where it gets darker as you add things.




You can render it using an unbiased light cache method too which actually works pretty fast considering, and gives it a more noisy/stochastic kinda look which smooths out the longer you render (like maxwell render)

Getting it to balance memory and cpu cores was a bit tricky, default render settings tend to lock up and not use multi cores properly when geometry is this dense. Also it seems when polygons overlap exactly as they often do in these cases the renderer locks up focusses on one thread/core hanging all the others and then eventually pushes thru. Tweaking render settings seems to have removed this issue or at least made it less apparent keeping all cores at 100%
In any case it renders fairly fast now compared to previous efforts, though It's still devastatingly slow for animation.


Lots of balls

:-)

And cubes