Geometric Assistance for the Construction of Non-Polyhedral Solids From Orthographic Views

As the extensive use of solid models becomes widespread, it is important to have a mechanism by which existing engineering drawings can be converted into solid models. Therefore, a geometric assistant which can aid in the construction of solid models is beneficial. In this paper, we present key operations for a system called the Assistant for the Rapid Construction of Solids (ARCS), that provides this assistance given a set of two orthographic views. ARCS is based on the Visual Reasoning Tutor (VRT), a system we developed that provides users with the geometric framework to build polyhedral solids from their orthographic views. However, the geometric domain of ARCS encompasses non-polyhedral solids with cylindrical and spherical surfaces, such as those found in typical mechanical parts. We have devised the Cylindrical and Spherical Warping operations to create cylindrical and spherical surfaces, which use interactive computer graphics that guide a human user to build non-polyhedral faces of a solid. These operations are then illustrated with an example using ARCS to create the solid model of a typical mechanical part from its orthographic projections.