Environment mapping as seen in Quake 3

Now it is time for me to ask.
Can someone describe or suggest a solution to achieving environment mapping as seen in quake 3. It is ( as I think ) done with spherical or planar mapping texture coordinate generation.
I am not interested in mixing textures, etc. - just want to know about the math behind it.
The problem is that generic spherical mapping depends on camera rotation ( it uses eye coordinates ), also it distorts badly when applied to plane, when in quake 3 it does not. So it seems that we need to use planar mapping and/or playing with texture matrix.


sorry if u know this already but u might wanna have a scuzzy in the /scripts/ directory in the quake3 directory + find the shader that has the environment mapping on it and there’lkl be a few varibles there eg
tcmod scale .2 .2
tcmod scroll .04 .03
tcMod turb 0 .1 0 .01

theres also a document on the net written by brian hook etal describing the shaders that r used in quake, it was written for modellers/lvl designers but u should be able to glean some info from that me son

I’ve already checked it a lot of time ago .
I am not interested in it’s application or addition texture matrix manipulation - I need just tcGen environment description.