What can glStencil do?

Question

I'm wondering what the stencil buffer is and what it can do. Thanks

Answer 1

You can do Doom 3-style shadowing with them.

If you're feeling lazy and don't want to triangulate your simple polygons you can draw them using the stencil buffer.

Answer 2

http://en.wikipedia.org/wiki/Stencil_buffer

Basically, the stencil buffers allows you to draw only in parts "marked" in the stencil buffer, rejecting pixels where this "mark" doesn't have certain value.

Is used to clip rendering in non-rectangular shapes, and to do shadow volumes.

Answer 3

Doom3-style shadows, mirrors, reflections, masking polygons, clipping polygons, displaying scene depth complexity, and several other things. There are quite a lot of things you can do.

Check francis hill's "Computer Graphics using OpenGL" or "The OpenGL programming guide" for more info.