Forum: Poser Technical


Subject: Very odd P4 answer for the Tron lighting question

_dodger opened this issue on Dec 09, 2002 ยท 6 posts


_dodger posted Mon, 09 December 2002 at 3:31 PM

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.


_dodger posted Mon, 09 December 2002 at 4:11 PM

Here's a render using almost what I described above. This is just a quickie texture and no real example of my texturing skills... There's a medium-light blue light BEHIND Mike. I'll follw this up with smaller versions fot he tewxure and a JPEG conversion of the BUM file. The body (and nipples) colours are as follows: Colour: white Highlight: black Ambient: 160/240/213 Reflective: irrelevant

_dodger posted Mon, 09 December 2002 at 4:12 PM

This is the texture map

_dodger posted Mon, 09 December 2002 at 4:13 PM

And this file is a JPEG of the BUM file. If you open this in an image editor and save it as a Windows 24-bit BMP bitmap, then change the extension to BUM, P4 will use it as a bumpmap and not prompt for conversion.

_dodger posted Mon, 09 December 2002 at 4:18 PM

I should note that the render above uses the default Rembrandt lighting Poser starts with, except the orange backlight has been changed to sky blue and moved behind the figure, almost directly behind, yet it lights up the blue coloured parts of the BUMpmap just fine.


Anthony Appleyard posted Tue, 02 September 2003 at 11:51 AM

The "average of .BUM" color described above is blue=0, red=128, green=128 .