
The Cornell Box is a familiar test scene for radiosity rendering. It shows an area light,
casting smooth shadows with umbra and penumbra, diffuse indirect illumination and the
characteristic color bleeding that transports the color of the walls to the boxes near it.
Although WinOSi uses a very different rendering algorithm, the resulting image is almost
identical to the result of a radiosity renderer.
In addition WinOSi is able to cover all kinds of specular light transfer effects like
refractive glass, mirrors, caustics, point lights with sharp shadows, which are not possible
in the standard radiosity paradigm.
Both algorithms render the image iteratively making the image better and more exact with each
iteration. The Radiosity renderer principally generates a nice (resolution- and view-independent)
solution after a few minutes, while the rendering time for the above image was a few days.
Because the WinOSi image is calculated at pixel-level without storing the accumulated illumination,
it is resolution- and view-dependent, but the image quality is generally better than the
radiosity solution which is interpolated over polygon-vertices (compare the exact geometry of
the shadows for example).