Particle Visualization provides the ability to see both the macroscopic and microscopic structure of particle data sets. Particles are often represented in visualizations using iconic shapes, such as spheres and ellipsoids, to represent the data. Phong or Lambertian shading have traditionally been used to visualize particles, because of their ability to quickly show surface curvature. These local lighting models, however, do little to show the spatial relationships of the particles or aid in the perception of the macroscopic structure. Shadows can help disambiguate relative positions of object, but can result in sharp discontinuities at shadow boundaries and areas dominated by the ambient shading term. Ambient occlusion and silhouette edges are two methods to aid in the perception of the macroscopic structure without compromising the ability to visualize the microscopic structure. This thesis investigates the use of these two techniques with respect to particle visualization demonstrating their effectiveness. Effectiveness will be gauged with anecdotal feedback from the scientists who generated the data used for the visualizations.
Full Text (PDF)
Slides from my defense (Power Point)
| Title | Format | Notes |
|---|---|---|
| Ambient Occlusion Shading Movie 1 | MPEG-1 MPEG-2 |
This shows flybys of four data sets with and without color mapping applied. |
| Ambient Occlusion Shading Movie 2 | MPEG-1 MPEG-2 |
This shows how the direct lighting could be changed interactivly. |
| Silhouette Edges Movie 1 | MPEG-1 MPEG-2 |
The threshold for the silhouette edges can be changed interactively as well as the view point and field of view. |
| Silhouette Edges Movie 2 | MPEG-1 MPEG-2 |
Silhouettes also work for time varying data. These movies were actually generated by an application scientist, Jim Guilkey, here at the University of Utah. |
I have a movie that is a combination of Ambient Occlusion Shading Movie 1, the first part of Silhouette Edges Movie 1 and all of Silhouette Edges Movie 2. MPEG-1 (106 MB), MPEG-2 (97 MB).