A video-based rendering acceleration algorithm for interactive walkthroughs

Abstract We present a new approach for faster rendering of large synthetic environments using video-based representations. We decompose the large environment into ceils and pre-compute video based impostors using MPEG compression to represent sets of objects that are far from each cell. At runtime, we decode the MPEG streams and use rendering algorithms that provide nearly constant-time random access to any frame. The resulting system has been implemented and used for an interactive walkthrough of a model of a house with 260,000 polygons and realistic lighting and textures. It is able to render this model at 16-frames per second (an eightfold improvement over simpler algorithms) on average on a Pentium II PC with an off-the-shelf graphics card. Keywords Massive models, architectural walkthrough, MPEG video compression, virtual cells, video-based impostors Introduction One of the fundamental problems in computer graphics and virtual environments is interactive display of complex environments on current graphics systems. Large environments composed of tens of millions of primitives are frequently used in computer-aided design, scientific visualization, 3D audio-visual and other sensory exploration of remote places, tele-presence applications, visualization of medical datasets, etc. The set of primitives in such environments includes geometric primitives like polygonal models or spline surfaces, samples of real-world objects acquired using cameras or scanners, volumetric datasets, etc. It is a major challenge to render these complex Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/ur a fee. environments at interactive rates, i.e. 30 frames a second, on current graphics systems. Furthermore, the sizes of these data sets appear to be increasing at a faster rate than the performance of graphics systems. One of the driving applications for interactive display of large datasets is interactive walkthroughs. The main goal is to create an interactive computer graphics system that enables a viewer to experience a virtual environment by simulating a.walkthrough of the model