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This page is obsolete - a very large amount of work has been done in visibility since I last updated it.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.