Let S be a set of noncrossing triangular obstacles in R-3 With convex hull
H. A triangulation I of H is compatible with S if every triangle of S is th
e union of a subset of the faces of I. The weight of I is the sum of the ar
eas of the triangles of I. We give a polynomial-time algorithm that compute
s a triangulation compatible with S whose weight is at most a constant time
s the weight of any compatible triangulation.
One motivation for studying minimum-weight triangulations is a connection w
ith ray shooting. A particularly simple way to answer a ray-shooting query
("Report the first obstacle hit by a query ray") is to walk through a trian
gulation along the ray, stopping at the first obstacle. Under a reasonably
natural distribution of query rays, the average cost of a ray-shooting quer
y is proportional to triangulation weight. A similar connection exists for
line-stabbing queries ("Report all obstacles hit by a query line").