I have read some stuff about selection buffer and i have understood that you must render the scene 2 times, one time for selection, the other time for “colors” (i don’t know in wich order). So i would like to know if it’s not too slow, especially for commercial game like Quake III Arena, and if so, what techic do they use.
Thanks by advance.
The selection buffer in OpenGL is generally not too optimized on todays consumer level hardware, and therefore might be a somewhat slow. But if you are looking for other ways, you can see selection as just another form of collision detection. Cast a ray from the viewpoint through the pixel you click on, and see if that ray intersects any objects. That is one way to do it.