High-Order Visualization with ElVis

Abstract

Accurate visualization of high-order meshes and flow fields is a fundamental tool for the verification, validation, analysis and interpretation of high-order flow simulations. Standard visualization tools based on piecewise linear approximations can be used for the display of high-order fields but their accuracy is restricted by computer memory and processing time. More often than not, the accurate visualization of complex flows using this strategy requires computational resources beyond the reach of most users. This chapter describes ElVis, a truly high-order and interactive visualization system created for the accurate and interactive visualization of scalar fields produced by high-order spectral/hp finite element simulations. We show some examples that motivate the need for such a visualization system and illustrate some of its features for the display and analysis of simulation data.

Vizir: High-order mesh and solution visualization using OpenGL 4.0 graphic pipeline

“…In comparison with CPU based techniques [4], there is no duplicated subdivided meshes/solutions in the main memory. In comparison with techniques based on ray-tracing [5,6], we do not have to solve a non-linear problems. If the root finding problem for the ray tracing is naturally avoided, we still have to handle the correction of the estimated space coordinates.…”

“…• The interactivity may be limited Another procedure is to use ray tracing techniques for elements rendering (see [5,6]). But in this case, the solution rendering has the following drawback : given a pixel, there is no easy way to find the intersection of the ray with the surfaces.…”

Using ViZiR 4 to analyze the 4th AIAA CFD High Lift Prediction Workshop Simulations

“…To this end, a visualization error, corresponding to the gap between the numerical solution and its representation, is introduced and controlled [4][5][6][7][8] and the rendering obtained is, as a consequence, inaccurate. Some other approaches are based on raycasting [9][10][11]. For each pixel, rays are cast to determine the color for this pixel.…”