Fast Ray Tracing of Unevaluated Constructive Solid Geometry Models
We present a refinement of the ray tracing algorithm, for use with unevaluated constructive solid geometry models. Bounding enclosures around the children of a part are combined into a tree with nearly optimal minimum expected number of extent-ray intersections. An approximate evaluation of the expression represented by the part can be evaluated on the enclosure-ray intersections to find the subset of children that might be hit by a ray. These candidate children are then used to evaluate the expression exactly. Several criteria are suggested which allow early termination of the exact expression evaluation.
KeywordsUnion Operator Expression Tree Constructive Solid Geometry Auxiliary Tree Random Ball
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