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Real-Time Advection and Volumetric Illumination for the Visualization of 3D Unsteady Flow

This web page contains additional material accompanying the Eurovis 2005 paper "Real-Time Advection and Volumetric Illumination for the Visualization of 3D Unsteady Flow" by Daniel Weiskopf, Tobias Schafhitzel, and Thomas Ertl.

Abstract

This paper presents an interactive technique for the dense texture-based visualization of unsteady 3D flow, taking into account issues of computational efficiency and visual perception. High efficiency is achieved by a novel 3D GPU-based texture advection mechanism that implements logical 3D grid structures by physical memory in the form of 2D textures. This approach results in fast read and write access to physical memory, independent of GPU architecture. Slice-based direct volume rendering is used for the final display. A real-time computation of gradients is employed to achieve volume illumination. Perception-guided volume shading methods are included, such as halos, cool/warm shading, or color-based depth cueing. The problems of clutter and occlusion are addressed by supporting a volumetric importance function that enhances features of the flow and reduces visual complexity in less interesting regions.

Publication Download

A PDF version can be found here.

Videos

Animated visualization of 3D advection of a tornado data set. No volumetric illumination is applied.

Film of 3D advection of noise and dye. No volumetric illumination is applied.

Animated 3D advection with volumetric Phong illumination.

Animated 3D advection with volumetric cool/warm shading.

HLSL Code

Our implementation of the texture-based surface flow visualization exploits the functionality and speed of graphics hardware by making extensive use of fragment programs. The implementation is based on C++ and DirectX 9. The fragment programs are formulated as HLSL shader programs. GPU programming is strictly separated from CPU programming by using effect files (fx files).

The part of the fx file that implements the relevant aspects of advection and mapping between logical and physical memory can be downloaded.