Ray Tracing or Radiosity?

Radiosity, being a more realistic model, has a couple of advantages over ray tracing. First and the most important difference, radiosity takes into account the interaction of light with diffuse surfaces. Second, radiosity is able to better portray shadows. This is because it takes into effect the diffuse lighting surfaces, which affect shadows because objects begin casting off light. Thus, shadows under a radiosity model look better because all lighting sources, including diffuse surfaces, are taken into account.

Third, radiosity calculates everything ahead of time, so it is view point independent. A viewer could "walk" around a 3D rendered environment build off of a radiosity model, and everything is pre-rendered. In ray tracing, which is view dependent, the process of calculation must be repeated for each view. Ray tracing, though, takes less computational power and is resultingly more memory efficient. Finally, radiosity does not handle specular reflections.

By combining the benefits of these two technologies, we can get the best of both worlds. Check these pictures out. They combine ray tracing and radiosity. Talk about photorealistic...it's hard to tell the real ones from the rendered ones!

The rendered version

       

The real thing!

Another rendering

       

The real deal