Isometric perspective matrix?

[zzattack]

Does the game apply a perspective matrix over voxels before they're rendered? I'm not talking about the transformations from the HVA file but rather about any transformations done after that, so that we get the top-down look over it. Or perhaps the alternative way of placing a camera with static lookat direction is used, but I suppose that comes down to the same thing. Would anybody know the coefficients of this matrix? Or am I completely wrong and is some other technique used?