Maybe I would rather try to use fading pseudovolumetric Light meshes as seen in the tecno demo. Then set the blending mode to multiplication or addition, so the smke will only show up when it passes the light beams.
Here you can see what I ment when I said "fading pseudovolumetric light meshes": (the neon lights)
http://www.blitzbasic.com/gallery/view_pic.php?id=146&gallery=hr&page=1
Here you can see what I ment when I said "fading pseudovolumetric light meshes": (the neon lights)
http://www.blitzbasic.com/gallery/view_pic.php?id=146&gallery=hr&page=1