[Fluxus] texture transparency for particles

[gabor papp]

> from under the ground but I feared this might later interfere with viewing
> buildings from up close with a background that might involve sky and clouds.
that's another issue. as far as i know, fluxus depth sorts on object 
level, which means that the camera distance for each object is 
calculated then the objects are rendered in order from back to front. 
although the particles are depth sorted when the particle object is 
rendered, the whole particle primitive will be rendered at a time 
specified by its distance from the camera. this can interfere with the 
rest of the scene. polygon level depth sorting could be a solution, but 
fluxus does not do that as far as i know. dave will probably correct me 
if i'm wrong.

gabor