Vector Glyphs for Surfaces: A Fast and Simple Glyph Placement Algorithm for Adaptive Resolution Meshes

 Vector Glyphs for Surfaces: A Fast and Simple Glyph Placement Algorithm for Adaptive Resolution Meshes

Abstract: Visualization of flow on boundary surfaces from computational flow dynamics (CFD) is challenging due to the complex, adaptive resolution nature of the meshes used in the modeling and simulation process. This paper presents a fast and simple glyph placement algorithm in order to investigate and visualize flow data based on unstructured, adaptive resolution boundary meshes from CFD. The algorithm has several advantages: (1) Glyphs are automatically placed at evenly-spaced intervals. (2) The user can interactively control the spatial resolution of the glyph placement and their precise location. (3) The algorithm is fast and supports multiresolution visualization of the flow at surfaces. The implementation supports multiple representations of the flow–some optimized for speed others for accuracy. Furthermore the approach doesn’t rely on any pre-processing of the data or parameterization of the surface and handles large meshes efficiently. The result is a tool that provides engineers with a fast and intuitive overview of their CFD simulation results.
Paper(s): Zhenmin Peng and Robert S. Laramee, Vector Glyphs for Surfaces: A Fast and Simple Glyph Placement Algorithm for Adaptive Resolution Meshes in Proceedings of Vision, Modeling, and Visualization (VMV) 2008, 8-10 October 2008, Constance, Germany.( PDF file, video, web page)
Supplementary Images
(Click on images for higher resolution version)
mesh1 mesh2

The unstructured adaptive resolution boundary grid of a cooling jacket from a CFD simulation. The upper image is an overview of the boundary mesh, and the bottom is a close-up. These images illustrate how complex a typical mesh from CFD can be.

simple glyphs

Glyphs are rendered at the resampling grid cell centers for visible portions of the boundary geometry and its associated vector field. This example shows a simple ring geometry with a 20*20 resampling grid.

resampler

The circular footprint function with Gaussian filter kernel is applied at the surface of the ring which has edges as shown. The blue point is the center point of the resampling cell. Green and red points are sample points defined by the footprint function. Green contribute to the final representation whilst red have been filtered out.

footprint function

Left is the circular footprint function using 8*8 sized footprint-grid. On the right side, an 8*8 footprint look-up table with a Gaussian filter kernel.

chamber

A colored multi-resolution visualization of low resolution and high resolution glyphs applied with Gaussian filter is rendered to visualize the flow at the surface of a gas engine simulation. Color is mapped to velocity magnitude.

resampling on chamber

Our multi-resolution glyph-based visualization which is powered by Gaussian filter applied in order to depict the flow at a surface of an intake port mesh composed of unstructured, adaptive-resolution 221K polygons.

resampled jacket

Glyph-based flow visualization which is powered by Gaussian filter and multi-resolution applied at the surface of a cooling jacket - a composite of 228K unstructured, adaptive-resolution polygons.

Supplementary MPEG Videos
(Click on links to play)
Glyph Placement at the Boundary Surface of a Cooling Jacket Simulation
  1. Object Translation and Rotation.
  2. Switching Between Hedgehog and Resampled Visualization.
  3. Color Mapped to Velocity Magnitude.
512 x 512 (9.3 MB)
Resampling User Options Demonstrated on Diesel Engine Simulation Data
  1. Changing Resampler Grid Resolution.
  2. Grid Rotation and Translation.
  3. Comparison with Hedgehog Visualization.
  4. Color Mapped to Velocity Magnitude.
512 x 512 (7.6 MB)
Multi-resolution Visualization of Boundary Flow From a Gas Engine Simulation
  1. Multiple, independent, User-specified Resampling Grids.
  2. Second Grid Includes All the Functionality of First Resampling Grid.
  3. Color Mapped to Velocity Magnitude.
512 x 512 (10.4 MB)
Effects of Edge Detection
  1. Turing Edge Detection On and Off.
  2. Color Mapped to Velocity Magnitude.
512 x 512 (6.8 MB)
Glyph Placement at Boundary Surface of Two Intake Ports
  1. Vector Fields Magnitude Mapped Also To Glyphs Size.
512 x 512 (7.2 MB)

This page is maintained by Zhenmin Peng.
In case of comments, questions, suggestions, or collaboration ideas, please sent email to: cszp "at" swansea.ac.uk.
This file was last modified on: Monday 8th September 2008 17:44:35 AM

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