Orion Lawlor's PhD Thesis: Impostors for Parallel Interactive Computer Graphics
This page describes my parallel programming and computer graphics
work on impostors, which are 2D texture standins for real 3D geometry.
Impostors provide a substantial amount of latency tolerance and
rendering speedup, which can be used to render huge and detailed
models--like a model of the entire UIUC campus--with quality
antialiased rendering techniques, including soft shadows.
The best places to learn more about these techniques are:
I gave my final defense on 2:00PM Monday,
November 29, 2004 in 4407 Siebel. Defense Version of Dissertation (5.5MB, Updated 11/23)
- Sanjay Kale: Parallel Prioritization, Load Balancing
- Mike Heath: Parallel Algorithms, Numerical Analysis
- John Hart: Procedural Computer Graphics, Graphics Hardware
- Mike Garland: Model Simplification, Texture Synthesis
Selected Self Citations
Selected Prior Work
- Chen 1993 Viewpoint Interpolation. Nice exploration of the ways to morph and blend textures to interpolate between two viewpoints. Sadly, viewpoint interpolation is difficult to perform quickly, and hole-filling turns out to be a significant problem with this approach. See Mark 1999 warping thesis for more modern work on the same reconstruction problem.
- Maciel 1995 Imposters First paper to name "imposters"; idea is to replace geometry by images. Their usage of imposters was quite simple--they pasted fixed images onto the object bounding box.
- Shade 1996 Heirarchical Walkthrough. Replace a subtree of the scene graph with an imposter, for quickly rendering outdoor scenes.
- Schaufler 1996 Image Caching. Replace individual objects with imposters.
- Ward 1999 Ray Cache. Trace a random set of high-quality rays on a parallel machine, and reconstruct an image from the current subset of rays. Not imposters, but parallel, realtime, and prioritized; the only downside is that reconstructing an image from random rays is difficult, and the results are speckly.
- Pasman 2001 Low-latency. Remote rendering system which makes the explicit argument of imposters for latency tolerance.
- Harris 2002 Realtime Clouds. Imposter-based lovely cloud rendering.
- Humpreys 2002 Chromium (WireGL). Parallel rendering system based on OpenGL pipeline (Documentation).
Prelim Report, final revision (PDF 7.3MB).
(4-up PDF 1.0MB)
The prelim was held 4:00pm Monday, April 12, 2004.
(Updated Wednesday, December 21 2005: Finally added movies.)
(... many updates in preparation for defense...)
(Updated 4pm Sunday, November 7: Added final defense schedule.)
(Updated 4pm Sunday, April 11: Final version of slides.)
(Updated 3am Sunday, April 11: Added slides.)
(Updated 6pm Thursday, April 1: Final version.)
(Updated 11pm Wednesday, March 31: Incorporate suggestions from
Kale and Sayantan.)
(Updated 2am Wednesday, March 31: Example images from penumbra limit maps,
upload self-citation papers.)
(Updated 4pm Saturday, March 27: More graphics references.)
(Updated 2am Saturday, March 27: Incorporate Kale e-mail edits, a few
(Updated 2am Thursday, March 25: Incorporate Kale edits, rework most
(Updated 2pm Wednesday, March 24: Better fundamentals section, more
Orion Lawlor, email@example.com, 3/23/2004