Hmm, I'm not sure that volume lightmap program is the correct one - what I saw was a small routine to just return the colour from the lightmap at the position of an entity. I've done this myself with just a few lines, but for some reason reading the pixel colour from the lightmap is very very slow - even a single read every render loop drops the framerate, and I've tried using lockbuffer and readpixelfast - I must be doing something wrong somewhere - any ideas anyone?
Upon loading the lightmap, make and store a copy of it in a bank or array...read the colors from there, NOT the lightmap stored in video memory.