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Bump and normal maps

PostPosted: Sun May 25, 2008 7:29 am
by Marcello
When Trylon was working on materials and blending, a long time age, we talked a bit about bump maps and normal maps. Both are being used (although not much) by Cyan. Do they both work in the current plugin? If so... do we also have something like illumination maps?

Re: Bump and normal maps

PostPosted: Sun May 25, 2008 2:19 pm
by Nadnerb
normal maps do not work in the current plugin, as using them appears to be a bit more complicated than one might expect, (requiring at least 3 special lookup texture layers) and there hasn't appeared to be much call for them.

You talk about "normal maps" and "bump maps" as if they were two different things, both of which would be available in plasma. Both names have been used to refer to the single effect that is actually available in plasma, which is the use of a normal map (rgb) to make a dynamically lit surface appear bumpy. Not to get into semantics over these terms, but it seems to come up every time someone mentions them. The other common meaning attributed to "bump map" being more like "displacement map", (ie grayscale) which would visually deform the surface of a single face, is not something you should expect from a real time engine as old as plasma.

Also, what do you mean by "illumination maps"?

Re: Bump and normal maps

PostPosted: Sun May 25, 2008 2:53 pm
by Marcello
Thnx Nadnerb. I'm aware of the difference, but didn't know Plasma does not support bump maps.

About illumination maps, I used the wrong term. I should have used specularity maps, which are used to influence the intensity and glossiness of reflection. For instance a piece of metal would never have a clean reflection, but have scratches and stuff that make some parts reflect more than others. Some parts are more matt and others more glossy. From what I read they are also greyscale with the white parts being the most glossy.

Re: Bump and normal maps

PostPosted: Sun May 25, 2008 3:19 pm
by Nadnerb
In that case, I think I've answered that exact same question before. We don't have the ability to use a texture to control the vertex specularity, however, an equal and-or better effect can be achieved by using a stencil on an environment map layer, or simply an envmap with a texture overlay containing alpha. (this is used quite a bit by Cyan, specifically in Ahnonay.)