This simple scene demonstrates some benefits of the global illumination model used in WinOSi
over standard raytracing:
1) See how naturely the room in the left picture looks, especially the
lighting and shadowing of the smaller sphere.
2) The area light casts a smooth shadow with penumbra onto the back wall,
but on the floor under the sphere the shadow has a very sharp edge which is difficult for
radiosity renderers. Raytracers can only emulate area lights with an immense effort on
additional rendering time.
3) Due to a constant ambient factor in the raytracer, all shadows are
uni-color and no edges are distinguishable inside the shadow on the right picture. In reallity
the shadow intensity varies over the area depending on other surfaces spending diffuse indirect
illumniation as in the left picture. (The shadow gets darker near the bottom of the sphere
because it blocks most indirect illumination there.
4) Note that WinOSi does perfect antialiasing without any extra effort.
5) Last but not least: Rendering time for the WinOSi-image was considerably
longer than the raytraced version...