Hierarchical Image Caching for Accelerated
Walkthroughs of Complex Environments

Overview

We present a new method that utilizes path coherence to accelerate walkthroughs of geometrically complex static scenes. As a preprocessing step, our method constructs a BSP-tree that hierarchically partitions the geometric primitives in the scene. In the course of a walkthrough, images of nodes at various levels of the hierarchy are cached for reuse in subsequent frames. A cached image is reused by texture-mapping it onto a single quadrilateral that is drawn instead of the geometry contained in the corresponding node. Visual artifacts are kept under control by using an error metric that quantifies the discrepancy between the appearance of the geometry contained in a node and the cached image. The new method is shown to achieve speedups of an order of magnitude for walkthroughs of a complex outdoor scene, with little or no loss in rendering quality.

Images


A top-down view of the island.	An artifact-free view created using hierarchical image caching.	A view created by drawing geometry.	A view of the BSP nodes.

Personnel

Jonathan Shade - Graduate
Dani Lischinski - Post-Doctorate
Tony DeRose - Professor
David Salesin - Professor
John Snyder - Microsoft Research

Software

Walkthru system. This should compile and run on an SGI system that has texture mapping hardware. It has only been rigorously tested on an Indigo2 Maximum Impact.
[gzip compressed tar file, 9 MB]
island_2032_2. Island data set with 2032 trees. [gzip compressed tar file, 1.2 MB]
island_1117_2. Island data set with 1117 trees. [gzip compressed tar file, .9 MB]
island_574_2. Island data set with 574 trees. [gzip compressed tar file, .8 MB]
island_282_2. Island data set with 282 trees. [gzip compressed tar file, .7 MB]

Publications

Hierarchical Image Caching for Accelerated Walkthroughs of Complex Environments Jonathan Shade, Dani Lischinski, David H. Salesin, Tony DeRose, and John Snyder. SIGGRAPH 96.
[PDF with High Resolution Figures, 180K]
[Compressed Postscript with High Resolution Figures, 2.8MB]
Figure 5 [EPS]
Figure 6 [EPS]
Figure 7 [EPS]
Figure 4 row 1a [Compressed EPS]
Figure 4 row 1b [Compressed EPS]
Figure 4 row 2a [Compressed EPS]
Figure 4 row 2b [Compressed EPS]
Figure 4 row 3a [Compressed EPS]
Figure 4 row 3b [Compressed EPS]

Last updated on May 19, 1998.

Hierarchical Image Caching for Accelerated Walkthroughs of Complex Environments