Interactive Visualization of Gaps and Overlaps for Large and Dynamic Sphere Packings.

To gain insight into many properties of granular matter, a particle packing can be simulated. For a dry particle mixture, collective rearrangement is often used as an iterative process to place the particles. In this paper, we present a new visualization technique to judge the quality of a collective rearrangement simulation of many spheres with a given particle size distribution. In addition to a visualization of the spheres themselves, we directly visualize the gaps and overlaps of the spheres in each iteration. This allows to see the regions where the simulation is not yet converged as well as the free spaces where spheres can still move into. Our method supports millions of spheres at interactive to real-time frame rates, allowing the user to inspect the sphere packing during the simulation. We demonstrate that this type of visualization better shows the structure of the current sphere arrangement than standard techniques like 2D clipping planes and therefore serves as a visual feedback to support the development of the packing simulation.