edit make sure to watch the video wow ! http://www.youtube.com/watch?v=l05HgqQbUs4
just thought i would post a link to this, really interesting technique that atleast ive never seen before and thought some of the more competent coders out there working on bge might be interested in.
from the link :
“Volumetric Billboards extend the classic billboards technique which renders complex 3D objects in real-time using textured quads in place of full geometry. Contrary to 2D billboards, volumetric billboards use volumetric images of the objects instead of 2D images. The images are stored into 3D textures. They are rendered with a dedicated real-time rendering algorithm based on geometry shader.”