Tiled Hardware-Accelerated Texture Advection for Unsteady Flow Visualization

Particle tracking in liquid and gaseous fluids is a very useful technique to better understand flow dynamics. In this paper, we develop a novel algorithm to track a dense collection of particles in unsteady two-dimensional flows. To capitalize on the rapid improvements in graphic hardware technology, the algorithm is exclusively based on subsets of the OpenGL implementation of SGI. Making use of several proposed extensions to the OpenGL1.2 specification, animations of over 5 3 10 × are produced at one frame/sec. on an SGI Octane with EMXI graphics. These animations are based on a multidomain implementation that overcomes hardware limitations such as insufficient memory in the hardware frame buffers to store temporary arrays and the low number of bits per color channel in buffers and textures. High image quality is achieved by careful attention to edge effects, noise frequency, and image enhancement. We provide a detailed description of the hardware implementation, including temporal and spatial coherence techniques, multidomain tiling, and the effect of hardware constraints on the precision of the algorithm.