sitemap

contact

University of Stuttgart

	Institute for Visualization and Interactive Systems
	Progressive Iso-surfaces on the Web

Next: Introduction

Progressive Iso-surfaces on the Web

Klaus Engel, Roberto Grosso, Thomas Ertl

Abstract:

Visualization of volume data on the WWW using the Virtual Reality Modeling Language (VRML) and the Java programming language offers new perspectives for distributed and platform independent applications. A naive approach would either transfer the volume data to the client side for local processing or it would compute the iso-surface on the server side by a marching cubes algorithm and transfer the resulting polygons to the client. In both cases the network bandwidth would be the limiting factor for large data sets. In this paper we try to overcome this restriction by using a progressive iso-surface algorithm, which allows the generation of surface hierarchies from the volume data with a level-of-detail control (LOD). The surface hierarchy is generated on the server and the levels of resolution are transmitted to the client progressively, i.e. only the difference between two successive levels is sent across the network. In order to be platform independent on the client side, a Java applet running in a web-browser is used to reconstructs the hierarchy progressively. The visualization of one level of resolution is done by a VRML web-browser plug-in, which allows the use of 3D graphics hardware support. The plug-in receives the geometry from the applet using the External Authoring Interface (EAI). In order to avoid the transmission of a large number of polygons, the user can reconstruct the surface up to a coarse level of resolution and refine it if required. The surface hierarchy can be visualized at any level of detail up the finest level available, while the applet continuesly reconstructs the hierarchy progressively.

Klaus Engel
Mon Mar 30 11:23:18 MES 1998