Interactive constraint-based solid modeling using allowable motion
Mingxian Fa, Terrence Fernando, Peter M. Dew · 1993
Thw paper presents a new approach to constraint-based solid modeliing that supports the interactive construction and modification oj solid models using SD in.puI devices such as a spaceball or dataglove.The goal is to develop a more intuitive, graphically based solid rnodelling system that ezploits the advances in 9D input devices.This goal has been achieved by integrating direct 3D manipulation and procedural constraint propagation approaches.The main contribution oj the paper is a technique re~err-edto as allowable motion that enables the accurate 3D posifionirrg of a solid model by automatically constraining its 3D manipuia.tions.Assembly relationship and geometric constratnt$ bettveen entities are automatically injerredfrom the 3D rnanijr.ulotion oj the solid model and stored in a Relationship Graph (R G).The allowable motion oj the solid model i., !hen compu(edjrom sta constraint Snjormatton In the R(;, .4prototgpe system has b~en implemented to demonstrate the feasibility oj the approach.This system is capable oj automatically injerrvng assembly operations purely from 5'D manipulations carried out by the designer.The system also supports /he 3D construction oj constraint-based soltd models tiszng a set of virtual design tools.