> Regarding your last point .. I thought the point of ray tracing is that you get a lot more realistic images than with OpenGL With basic (i.e. Whitted) ray tr

> Regarding your last point .. I thought the point of ray tracing is that you get a lot more realistic images than with OpenGL With basic (i.e. Whitted) ray tracing, you get shadows, reflection, and refraction. You can do that in OpenGL too, but it's more work and you have to do go through some unnatural contortions and/or use approximations that might look convincing but aren't physically accurate. Soft shadows, focal blur, and motion blur can be supported by tracing more rays per pixel. The big leap in realism (the kind where you would say ray tracing is definitely better than what you would see in a modern game) comes when you add global illumination, which is computationally a lot harder than basic ray tracing because it requires a large number of rays per pixel. It works by random sampling, so you can generate a blurry, grainy image fairly quickly, but noise-free images take a lot longer.