Editing curves and surfaces is difficult in part because their mathematical
representations rarely correspond to most people's idea of a curve or surf
ace. The implementation land hence, behavior) of most manipulation tools is
intertwined with a particular curve or surface representation; this can ma
ke reimplementing the tool with a different representation problematic. A s
ystem using a single representation must therefore either limit the types o
f tools available or convert existing tools to work on the system's represe
ntation.
In this paper we present a framework for editing curves or surfaces which s
upports multiple representations and ensures that they stay synchronized. A
s a proof of concept, we have created a curve editor which contains several
tools each of which manipulate one of three different curve representation
s: polylines, NURBs, and multiresolution B-splines.