Michael B. Stephenson

Optismoothing: an optimization-driven approach to mesh smoothing

Abstract This paper presents a mesh smoothing technique that uses optimization principles to minimize a distortion metric throughout a mesh. A comparison is made with laplacian and isoparametric smoothing techniques.

Analysis automation with paving: A new quadrilateral meshing technique☆

Abstract This paper describes the impact of paving, a new automatic mesh generation algorithm, on the analysis portion of the design process. Paving generates an all-quadrilateral mesh in arbitrary 2D geometries. The paving technique significantly impacts the analysis process by drastically reducing the time and expertise requirements of traditional mesh generation. Paving produces a high quality mesh based on geometric boundary definitions and user specified element sizing constraints. In this paper we describe the paving algorithm, discuss varying aspects of the impact of the technique on design automation, and elaborate on current research into 3D all-hexahedral mesh generation.

A polyhedron clipping and capping algorithm and a display system for three dimensional finite element models

This paper describes an algorithm for clipping and capping polyhedrons and a display system for three-dimensional finite element math models to facilitate viewing internal surfaces in the form of continuous tone computer generated color images. A plane is passed through the model with the result that the elements (or portions thereof) on one side of the plane may be eliminated. A new grid is generated for the cutting plane to include the prediction of such quantities as displacements, stresses, and temperatures. The Cutting plane is colored and/or warped to indicate the variation of selected scalar functions.

Ray traced scalar fields with shaded polygonal output

An algorithm for rendering scalar field data that reduces rendering times by as much as two orders of magnitude over traditional full resolution images is presented. Less than full-resolution sampling of the scalar field is performed using a fast ray tracing method. The sampling grid points are output as a set of screen-based Gouraud shaded polygons which are rendered in hardware by a graphics workstation. A gradient-based variable resolution algorithm that further improves rendering speed is presented. Several examples are presented.<<ETX>>

High Performance Calligraphics

Dyna-MOVIE.BYU combines software and Evans and Sutherland hardware providing a highly interactive program with instantaneous feedback of object transformations; therefore, real time, dynamic calligraphic display capabilities are possible. All transformations are updated continuously by use of three interactive devices: a keyboard with function keys, the control dials and a data tablet. Two methods are available to remove hidden surfaces. Animated sequences can be produced by defining a series of frames. The frames are calculated and down loaded from the host computer to the PS330. The sequence can be previewed by three different methods. Since, the PS330 is a calligraphic display device, the final picture can be saved in a MOVIE.BYU format file. This allows the user to choose a number of continuous-tone raster devices on which the model may be rendered.