Solid Modelling for Manufacturing: From Voelcker’s Boundary Evaluation to Discrete Paradigms

Herb Voelcker and his research team laid the foundations of Solid Modelling, on which Computer-Aided Design is based. He founded ambitious Production Automation Project, that included Constructive Geometry (CSG) as basic 3D geometric representation. CSG trees were compact robust, saving a memory space was scarce in those times. But main computational problem Boundary Evaluation: process converting to Representations (BReps) with explicit faces, edges vertices for manufacturing visualization purposes. This paper presents some glimpses history evolution ideas started Voelcker. We briefly describe path from “localization boundary evaluation” printing”, many intermediate steps driven by hardware, software new mathematical tools: voxel volume representations, triangle meshes, others, observing also applications, models no longer require Evaluation. In this last case, we consider current challenges discuss several avenues further research.