Oh, I must've misread that part.
<spam>
The transparency flags are in the .wld file as you sort of already demonstrated above. The visibility flag is it. You can set transparency (I'd call it "masking", there are other transparency modes) on textures that aren't supposed to be transparent at all and you'll end up with a texture with random holes in it. My assumption is that it grabs the first or last index color in the palette and uses that for the transparent color (assuming BMP -- PNG and JPEG textures also work in addition to DDS, I can't remember if they use the alpha value to exclude pixels under a certain threshold or not, but that would be the expected way to do it). It's usually the color in the lower-right corner as well, but not always... (None of the EQ BMP files appear to use the BMP extensions that allow designating a color for transparency, as far as I've seen; the client just looks in some standard place.)
A single texture can actually have multiple separate visibility flags applied to it for different models, but I don't think the texture patcher is sophisticated enough to distinguish between different instances of the same texture in the .wld file. Hence why it opens up a hole in the back of female human plate helms, apparently.
</spam>
|