Imposing the additional physical constraints of energy conservation and Helmholtz reciprocity allows us to create variations of the conventional shaders that are more physically plausible. As presented at the 1992 Western Computer Graphics Symposium in Banff, Alberta. After overviews of the global illumination problem and of radiosity, we describe the latter's solution via multigrid methods. Although few researchers currently use classic radiosity, we discuss possibilities for the adaption of multigrid methods to more recent radiosity solution techniques. Such texturing has been done in the past with texture mapping, particle systems, or volumetric methods.
Lattices work as fast but inexact ray tracers.
As long as lattices are used for small objects, though, the inexactness doesn't show on the scale of the display, and the result is acceptable. The paper shows how lattices can be integrated with a more traditional ray tracer, with several examples. Time and memory space considerations are major constraints on lattices, preventing widespread application at the present time. The paper discusses these limitations and how they might be reduced. Unlike most other window managers, Galadriel runs under UNIX on a hosted, display list terminal instead of a bitmapped workstation.