authors 
Woodwark, J.R. 
year 
1989 
title 
Splitting SetTheoretic Solid Models into Connected Components 
source 
10 p. : ill. Winchester: IBM UK Scientific Center, IBM United Kingdom Laboratories Limited, June, 1989. IBM UKSC 210. includes bibliography In general, there is no way to tell how many pieces (connected components) a settheoretic (CSG) solid model represents, except via conversion to a boundary model. Recent work on the elimination of redundant primitives has been linked with techniques for identifying connected components in quadtrees and octtrees into a strategy to attack this problem. Some success has been achieved, and an experimental Prolog program, working in two dimensions, that finds connected components and determines the settheoretic representation of each component, is reported, and further developments proposed. CSG / quadtree / octree / primitives / algorithms. 43. Woodwark, J. R. and Quinlan K. M. 'Reducing the Effect of Complexity on Volume Model Evaluation.' Computer Aided Design. April, 1982. pp. 8995 : ill. includes bibliography. 
summary 
A major problem with volume modelling systems is that processing times may increase with model complexity in a worse than linear fashion. The authors have addressed this problem, for picture generation, by repeatedly dividing the space occupied by a model, and evaluating the submodels created only when they meet a criterion of simplicity. Hidden surface elimination has been integrated with evaluation, in such a way that major portions of the model which are not visible are never evaluated. An example demonstrates a better than linear relationship between model complexity and computation time, and also shows the effect of picture complexity on the performance of the process 
keywords 
CAD, computational geometry, solid modeling, geometric modeling, algorithms, hidden surfaces, CSG 
series 
CADline 
references 
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last changed 
2003/06/02 11:58 
