GRIN: Interactive Graphics for Modeling Solids

Abstract

This paper describes an experimental system for the original generation and subsequent modification of volume models of complex physical objects, using interactive computer graphics. The models are built up from primitive volumes, e.g., cuboids, cylinders, swept sutfaces, etc., entered by a mechanical engineer interacting with a two dimensional projection of the model on a graphic display screen. The primitives may be entered at any orientation in 3-space and combined to form a single polyhedral model. The central issue is the provision of an eficient, natural means for generating these models. It was in this environment that the research reported here was undertaken. The work was intended to answer some fundamental questions regarding mechanical CAD Copyright 1981 by International Business Machines Corporation. Copying is permitted without payment of royalty provided that (1) each reproduction is done without alteration and (2) the Journal reference and IBM copyright notice are included on the first page. The title and abstract may be used without further permission in computer-based and other information-service systems. Permission to republish other excerpts should be obtained from the Editor.

On the Automatic Dimensioning of Technical Drawings

“…Its application is limited because in CSG the geometric objects must be defined procedurally and built from set-theoretic combinations of primitive 3-D models. More work on dimensioning objects created with CSG can be found in [14,15,30]. Hashimoto [17] presented an algorithm for automatic dimensioning of 2-D drawings.…”

The emerging technology of CAD/CAM

“…Typically, CSG systems provide a set of primitive simple objects such as blocks, cylinders, and cones; a set of operators similar to set union, intersection, and difference is used to combine objects to form more complex objects. Figure 5a shows the simple bracket of Figure 4a modeled as a combination of primitive objects, while Figure 5b is part of a robotic assembly line modeled and simulated on IBM's GDP/GRIN [4]. Many systems based on CSG are in use, including PADL, GMSOLID [2], GDP/GRIN, and Synthavision.…”

OYSTER: A Study of Integrated Circuits as Three-Dimensional Structures

“…The Geometric Design Processor (GDP) [9,10] is a geometric modeling system that provides these facilities. GDP is the basis for the discussion of simulation of process steps and analysis of device properties, and also for the implementation of the feasibility study given in this paper.…”

“…Much work has also been done on the derivation of operating characteristics and performance of known device structures [5][6][7]. In a totally different domain, namely mechanical engineering, solid geometric modeling has become accepted as an interactive design and analysis tool [8][9][10]. Solid modeling has also been the basis for much work on application algorithms for manipulating models in domains such as robot programming and machine toot control.…”