title: OpenGL water refraction
body: <p>I'm trying to create an OpenGL application with water waves and refraction.  I need to either cast rays from the sun and then the camera and figure out where they intersect, or I need to start from the ocean floor and figure out in which direction(s, if any) I have to go in order to hit the sun or the camera.  I'm kind of stuck, can any one give me an inpoint into either OpenGL ray casting or a crash course in advanced geometry?  I don't want the ocean floor to be at a constant depth and I don't want the water waves to be simple sinusoidal waves.</p>