quote:
It was very cool too see my terrain self shadow real-time while the "sun" moved around.

Yeah, shadowmaps are cool, aren't they You won't get this with stencil shadows...

quote:
I'm afraid some of the math provided for the "perspective" shadow maps is too complex for me to understand without any code, visual explanation or such. I read the "Perspective Shadow Map" paper and the explanations didn't relate well enough. Maybe I'm trying to jump into something too quickly

The 'perspective shadow maps' paper is excellent, the technique described can be used to get rid of most of the aliasing artifacts. But it is actually not that easy to implement. A standard shadowmapper is already a very good start. Once you understood all the math behind it, then you can attempt the PSM paper.

quote:
Explain 4-d texture coordinates. How the heck does transforming oT0.x y z and w "project" the texture?

The same way as 4D coordinates project a vertex - by dividing by the homogeneous coordinate. Just think of your texcoords as regular coordinates for a vertex. But instead of projecting it onto the screen, you project it onto the scene. If you haven't already, look at this nVidia paper, it explains the concept of projective textures.

quote:
How am I to take the depth buffer if there is none?? I'm rendering my light from an orthogonal aspect ( it's a directional light ), meaning -there is no depth!- Can someone explain this ?

Orthogonal projection still has a depth value - it's just not used to perspectively distort the coordinates (as in perspective projection). But it still is there, and represents the distance of objects from your camera (or light in the case of shadow mapping) Otherwise the zbuffer wouldn't work at all. It's pretty much the same thing as with perspective rendering, ie. z is still interpolated over the surface, compared and store to the depth buffer, etc. It is just not used in the projection equation.

/ Yann

[edited by - Yann L on October 24, 2002 1:18:12 PM]