Actually surprisingly enough - while you do have to map your mouse coordinates into device space (in the form of a ray) - OpenGL (legacy) does have picking functionality with the GL_SELECTION render mode (see https://www.opengl.org/archives/reso.../selection.htm) or with modern OpenGL 3+ you can use occlusion queries to produce equivalent functionality or you can create your own system by testing against a depth buffer etc
If you require per-poly / per-pixel picking then in all but the most simple of scenes? it will be faster to optimize picking with the GPU.
Bare in mind however that it's not a free operation and while it's often faster than a CPU bound solution - you may still want to do it on the CPU anyway. As always benchmarking weighed against the other things you're doing on the GPU is recommended.
I guess it depends if your game is CPU bound or GPU bound.
Reply With Quote
Bookmarks