Visibility and Occlusion Culling
This page is obsolete - a very large amount of work has
been done in visibility since I last updated it. Interested readers may wish to
check out Xavier Decoret's
visibility
bibliography.
In computer graphics, visibility calculations are used to see whether
or not you need to draw an object. For fine-grained visibility
calculations (also called "clipping") these objects are primitives such
as lines and polygons. Some of my research has been in the area of
large-scale visibility calculations, in which the objects are clumps of
polygons such as the models of rooms and furniture used in an
architectural walkthrough. Chris Georges and I wrote a paper on a simple, fast way to do
this kind of visibility culling; later I implemented the technique
described in the paper pfPortals, a
library for SGI's Performer
high-performance rendering toolkit. If you're interested in the
pfPortals algorithm, you may also want to check out Dan Aliaga's work on portal
textures, an extension to the pfPortals algorithms that dynamically
replaces portals with textured polygons.
The pfPortals home page.