Offsets, sweeps, and Minkowski operations (M-ops) are easy to define in the
existential (representation-free) mathematics of point sets, but computing
'values' for offset, swept, and M-summed entities is thought to be difficu
lt by many. This article argues that such computations may be easy if (1) t
hey are cast in specific application contexts, and (2) relevant mathematica
l definitions are discretized and implemented directly. The argument is bas
ed on 10 years of research on a range of motional, process-modeling, and vi
sualization problems that involved offsetting, sweeping, and M-ops; the sol
ution paradigm common to all was direct approximation of mathematical defin
itions, using ray representations and parallel computation as primary media
. This article presents no new results; it merely summarizes a body of well
documented research that illustrates an approach to problem solving, whose
primary tenets are: compute only what you need to solve the problem at han
d, and do that as directly as possible. (C) 1999 Elsevier Science Ltd. All
rights reserved.