I need to create a texture that contains the overdraw after a certain amount of draw primitives. I need this to work as fast as possible on the last NVidia cards (It’s not only for debug display). The image will be further processed in GLSL.
I saw that I can use GL_NV_copy_depth_to_color, but is there a way to achieve the same result without coping.
What about accumulation buffer? Should I try it? Is it still so slow?
I will work with really big texture, so I would like to avoid the coping.