Particle Flurries: a Case Study of Synoptic 3D Pulsatile Flow Visualization

We present Particle Flurries, a case study of our efforts toward a synoptic visualization of pulsatile 3D flow that strives to show viewers all flow features simultaneously. The contributions are: a flow visualization technique for stereo viewing that quickly shows particle flow details throughout a volume; a novel poisson-based seeding strategy that prevents redundancy in the particle visualization; interactively controlled “sponges” that can emphasize specific areas of flow; and “kelp” that highlights flow behavior near surface geometry. Our solution uses immersive stereoscopic VR to display a novel volume-filling particle animation of complex 3D flow together with a visually rich wall representation that reveals the wall geometry, shows data near surfaces, and minimally obscures flow. We developed a tunable particle display algorithm that is both sparse and Poisson-disk-like distribution based; these two features ensure, respectively, that individual flow features are easily seen and that all flow features are shown over time. Interactive tools bias the display algorithm to provide different synoptic views to explore and emphasize various flow qualities such as near-wall flow or fast flow. We studied a number of visual design choices, for example haloing motion-blurred particles, that further enhance 3D viewing and synoptic visualization. Our novel seeding algorithm can reduce the number of seeds required to generate a synoptic particle animation of complex 3D flow by 93% over comparable fixed-interval seeding algorithms. We successfully applied this technique to both internal and external flows. Using our technique, domain experts informally reported that they could better understand the details of complex 3D flow and could find unexpected features more quickly than with laboratory experiments or 2D viewing tools.