Hidden line and contour plotting algorithms in CAD-FEM aplications

• Type: Article in International Conference Proceedings Book
• Date: 1992

Authors

Carlos Reis Gomes (Author) FEUP; Renato Natal Jorge (Author) FEUP; L. Coimbra (Author) Other; Joaquim Fonseca (Author) FEUP

Conference proceedings International

Title: Second International Conference of Computer Graphics and Visualisation Techniques

COMPUGRAPHICS¿ 92 - Second International Conference of Computer Graphics and Visualisation Techniques

Lisboa

Other information

Resumo (PT): This paper describes the work developed in the Department of Mechanical Engineering to incorporate in the same package a CAD program and a pre/post processor for Finite Element Analysis. The objective is to provide the undergraduate and post graduate students with a basic tool whose facilities and possibilities could be developed over the years. The first stage of development involved the implementation of automatic mesh generation algorithms for 2D problems, that was presented at theCOMPUGRAPHICS '91. The algorithms implemented were the Transfinite Interpolation and the Elliptic System. At the same time same basic functions to manipulate mesh entities and visualise results of analysis, were created. Since then, the program has been upgraded to include algorithms to create 3D meshes, to perform hidden line removal and the post processing of scalar, vector or tensor quantities in contour mode. The hidden line removal algorithm consists of three steps. In the first step the exterior facets of a 3D mesh are detected. In a second step the "backfaces" are removed. In the last step the "painter algorithm" is used to eliminate surfaces that are covered by others. The algorithms presented here were implemented in CAD-FEM package using the X-Window interface which assures the portability of the program. The hidden line and contour plotting algorithms will be described in this paper.

Abstract (EN): This paper describes the work developed in the Department of Mechanical Engineering to incorporate in the same package a CAD program and a pre/post processor for Finite Element Analysis. The objective is to provide the undergraduate and post graduate students with a basic tool whose facilities and possibilities could be developed over the years. The first stage of development involved the implementation of automatic mesh generation algorithms for 2D problems, that was presented at theCOMPUGRAPHICS '91. The algorithms implemented were the Transfinite Interpolation and the Elliptic System. At the same time same basic functions to manipulate mesh entities and visualise results of analysis, were created. Since then, the program has been upgraded to include algorithms to create 3D meshes, to perform hidden line removal and the post processing of scalar, vector or tensor quantities in contour mode. The hidden line removal algorithm consists of three steps. In the first step the exterior facets of a 3D mesh are detected. In a second step the "backfaces" are removed. In the last step the "painter algorithm" is used to eliminate surfaces that are covered by others. The algorithms presented here were implemented in CAD-FEM package using the X-Window interface which assures the portability of the program. The hidden line and contour plotting algorithms will be described in this paper.

Language: Portuguese

Type (Professor's evaluation): Scientific