Large-Scale Interactive Walkthrough over the Web

Abstract

In this paper we present a Web-based environment for visualization of large-scale VRML models. Visualizing such large model consisting of thousands or millions of objects in it often causes significant latencies in transmitting over the Web. Furthermore, such models are usually too large to be fitted into local memory of common desktops for rendering. However, we realize that in most cases only very small portions of the model (instead of the whole one) need to be retrieved or manipulated at a time. To achieve this, we utilize a scheme that integrates binary trees with quad trees to describe the hierarchy of objects in the model in the preprocessing stage. By traversing the trees, we are able to effectively determine the minimal set of required objects in the walkthrough stage at run-time. Therefore, our system can yield lower latencies for transmission and less memory requirements for rendering with higher frame rates.