Sun & Moon cubes

Hi Guys,

I am working on a small project in which I like to display particles in a cube. The walls of the cube shall reflect the particles like it would be in a glassy / volumetric environment.

First tests are looking great but I have the feeling that I accomplish the task terrible insufficient.

Right now I use 2 particle systems, one within the cube and another one with similar parameters in combination with a blur and plasma patch to generate a texture for the walls. This creates a somewhat pseudo reflection.

I wonder if there is a more elegant way to accomplish this which is easier on the system resources as I plan to display some more in the background etc.

I attached the composition for you. Thanks in advance for all the help you can send me on my way.

-Peter