The Design Capture System: Capturing Back-of-the-envelope Sketches

SUMMARY A system which allows the computer to capture sketches made by a mechanical designer is described. The system not only recognizes basic design features as they are sketched, but it also builds a feature-based solid model of the artifact. The temporal nature of the capture, one feature at a time, serves to form a feature graph that allows for parametric redesign. The system is composed of three inference systems: a two-dimensional freehand primitive recognition system, a three-dimensional feature recognition system and a spatial reasoning system. Each is described in the paper.