Synthavision

SynthaVision from MAGI (Mathematics Application Group, Inc.) was released in 1972, not as CAD software but as a program for performing 3D analysis of nuclear radiation exposure. SynthaVision's 3D models were solid models similar to the CSG (constructive solid geometry) models used by later 3D CAD software. In general though, and despite steadily increasing computer performance, solid modeling was still too compute intensive for most practical applications. Extensive solid modeling research was done by Charles Lang's group (at Cambridge University) and by Herb Voelcker and his team (at the University of Rochester's Production Automation Project) throughout the decade and the approaches taken throughout the 1970s by the two groups were fundamentally different, as were the CAD software products ultimately based on their research.