It is well known that the conformal geometric algebra framework can greatly simplify intersections of planes, lines, circles and spheres in space. In this paper we will show how this system can be used very effectively for wavefront propagation/ray tracing from complex surfaces made up of plane segments or spherical caps. The conformal versions of 'reflection of a line in a plane' and 'reciprocal frame' are key to the process we will describe. The method will be illustrated on some complex triangluated surfaces.

jl@eng.cam.ac.uk