Giga-Scale Multiresolution Volume Rendering on Distributed Display Clusters

Part 1: Human Aspects of VisualizationInternational audienceVisualizing the enormous level of detail comprised in many of today’s data sets is a challenging task and demands special processing techniques as well as a presentation on appropriate display devices. Desktop computers and laptops are often not suited for this task because data sets are simply too large and the limited screen size of these devices prevents users from perceiving the entire data set and severely restricts collaboration. Large high-resolution displays that combine the images of multiple smaller devices to form one large display area have proven to be an adequate solution to the ever-growing quantity of available data. The displays offer enough screen real estate to visualize such data sets entirely and facilitate collaboration, since multiple users are able to perceive the information at the same time. For an interactive visualization, the CPUs on the cluster driving the GPUs can be used to split up the computation of a scene into different areas, where each area is computed by a different rendering node.In this paper we focus on volumetric data sets and introduce a dynamic subdivision scheme incorporating multi-resolution wavelet representation to visualize data sets with several gigabytes of voxel data interactively on distributed rendering clusters. The approach makes efficient use of the resources available on modern graphics cards which mainly limit the amount of data that can be visualized. The implementation was successfully tested on a tiled display comprised of 25 compute nodes driving 50 LCD panels