Parametric Height Field Ray Tracing

Height field ray tracing is one approach to photorealistic visualization of terrain. Parametric methods, which fall into a new class of height field ray trace methods, are introduced 1. The height field is horizontally sliced into evenly spaced cross-sections. For each cross-section, the Euclidean distance from each point to the nearest point where the slice cuts through terrain is computed off-line. These planes of distance values are condensed into parameter planes that encode cones of empty space above each height field cell, where cone width is bounded by the terrain relief. Parametric ray tracing occurs along intersections between rays and these cones. Parametric methods are shown to be memory efficient and often much faster than the other popular height field ray trace methods.