Light in krakatoa
I'd like to know the math behind light effect in krakatoa, ([click here](http://www.youtube.com/watch?v=3xaG882IJ44&feature=relmfu) for an example). 

Light source is traveling with particles, but how is shading done? Is it something simple, like Phong shading?

Is it possible to implement such effect in real time, on GPU?
Light in krakatoa
===

I'd like to know the math behind light effect in krakatoa, ([click here](http://www.youtube.com/watch?v=3xaG882IJ44&feature=relmfu) for an example). 

Light source is traveling with particles, but how is shading done? Is it something simple, like Phong shading?

Is it possible to implement such effect in real time, on GPU?