Original Post
OK, I''ve now got my projective textures working, so would like to try shadow mapping. This involves first rendering the scene from the lights point of view to a smaller(eg 256x256 viewport), obtaining te depth values for each pixel and using these as a texture.
How can I:
a) Render my scene so that the depth buffer is automatically rendered to a 256x256 texture?
OR:
b) -Reduce the viewport size to 256x256 (without changing the window size)
AND
-Read back depth values from the resulting image?
Thanks