i post this question when old message board was active. Since new one was opened, Nick repost all messages from old to the new one.
FlyFire/CodeX
http://codexorg.webjump.com
FlyFire/CodeX
http://codexorg.webjump.com
Volumetric fog can be approximated by calculating the fog color at each vertex of the tris over which the fog will be projected and interpolating the values in between vertices. OpenGL has an extension to specify fog colors for a vertex (much like texture coordinates).
For those mathematically inclined, the line integral is much like integrating f(x)dx, except dx is now a vector and x is a point in space. Or something like that. This stuff is usually covered in an advanced calculus course in college.
I have an example and a very (64 KB) article about volumetric fog done a few days ago.
Go to www.voodoospotlight.com/devknowledge/index.html
There you will find the article, an executable showing my algo and full source-code. You will need Power Render to recompile, however it's understandable even if you never heard about Power Render before.
Just check it out. I got a lot of positive feedback on my article. I think all answers here are covered in my article.
Phillip Schuster