What can glStencil do?

Question

I wonder what a stencil buffer is and what it can do.

Answer 1

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

In principle, stencil buffers allow you to draw only the parts “marked” in the stencil buffer, rejecting pixels where this “mark” does not have a specific value.

Used for clip rendering in non-rectangular shapes and for shadow volumes .

Answer 2

Shadows, mirrors, reflections, masking polygons in Doom3 style, cropping polygons, displaying scene complexity and much more. There are many things you can do.

For more information, visit francis hill "Computer Graphics Using OpenGL" or the "OpenGL Programming Guide".

Answer 3

You can make Doom 3-style with their help.

If you feel lazy and don't want to triangulate your simple ones, you can draw them using the stencil buffer.