I have a (cg) fragment program execute on big polygons, to increase the performances i tried to use additional clip plane (i could do manual clipping of course).
As i get non speed change i was asking if i missed something ? Is it the expected behavior or is it just my code which is buggy ?
it’s always been my experience that user defined clip planes are just plain slow. I would avoid using them if possible in performance critical areas. There’s an oblique frustum technique that might just do the trick in your case.
Here’s a link to a related paper:
Here’s a related thread:
thank for the links.
As i have to handle an unknow number of additional clip planes i finally decieded to do manual clipping and then draw the shape with GL_POLYGON. This gives a big performance boost.