Could someone give me a thorough explanation about multipurpose bitmaps? I cannot seem to get the effect I want when I make my own ugly multis :(.

Thanks!

What about alpha channels? What do they do in a multipurpose?

This thread will come in handy for our newcomer.

I'll be on in about an hour. Gotta go home and turn on my iPod Touch.

Yes, alpha channels help determine where the color changes, but I would like to elaborate:
Alpha modulates color change by how much white there is in a pixel of the texture.
Areas where the alpha is white will have full color change, or at least as much as much as the blue/red channels allow. Black will have no color change. Grey will have color change in between white and black.

Now what does the blue and red channels have to do with it? I really have no idea! For some reason though, having full red or full blue on your multipurpose doesn't make the diffuse texture look as good when colored. A good multipurpose will not have solid blue, red, or purple. As for green, if you want areas with full glow then you will need the full green in those areas, but to make it look like an area which glows, you should smooth the edges of the green.


A cool thing you can do is take either a bump map or a displacement map and apply it to your multipurpose (NOT YOUR DIFFUSE), and ingame the model will sorta look bump-mapped.
Here's an old example of mine that uses these tips:


Here's the original tag:
http://hce.halomaps.org/index.cfm?fid=3204

Custom cube maps help as well, and my shaders used some.
Edited by Enzo03 on Jan 26, 2011 at 01:11 PM

That is actually What I am doing. ImBrokeRU taught me that a year ago about putting 100% grayscaled normals onto multipurpose and about 20% opacity of the normals on the diffuse.

That takes up more space and will always be at a fixed depth :(

This is perfect, I understand model shaders a lot more now. Thanks so much for the intel. Bookmarked!

Try copying the BLUE channel of a normal map and apply it as a new layer with the blending properties set to "Multiply". This gives you the slightly accented shadows that a normal map provides.