I just for the hell of it decided to try and see what format BUM files really were -- they're Windows bitmaps. The extension has been changed to protect the guilty. If you 'Open As' a BUM file in Photoshop, you'll see what looks like what would happen if you lit (or embossed) the original with red from below left (7:30/135d) and green from above right (1:30/-45d). So I decided to play with this and draw on it and resave it as a different BUM file. Appears that if you use colours other than red or green, you get some very weird effects. I drew 'Test' on it in pure blue and the word was lit as if lit head-on from a light sitting slightly behind the plane (I was just using the ground plane). So here's my recommendation for whoever it was asking about Tron-style costumes before. Open a BUM map as a BMP and sample the average colour, which is a murky light olive green colour (actually almost exactly the colour of an unripe olive). Keep that colour handy. Actually, it's this colour, 7e8000 in HTML. Now, open up a copy of the UV template and add a layer and fill it with this colour. Find the locations you want to be tron-lit glowing style. On a new layer, draw in the lines in bright blue. Save this as a Windows 24-bit bitmap and change the extension to BUM. Select by this layer's opacity (Photoshop CTRL-Click the layer in the palette). Add a new layer and fill with white. Add a new layer behind this and deselect and fill that with dark-medium grey. Save a copy out as the texture map. In P4,load up the BUM and texture and then set a light in light blue slightly behind the figure to your right. It should just barely NOT light the figure. Set the ambient colour to a medium grey or blue. Render. The effects should look a lot like in Tron.