GigaVoxels DP: Starvation-Less Render and Production for Large and Detailed Volumetric Worlds Walkthrough

Abstract

Using voxel hierarchies as a generic 3D scene representation makes ray marching, antialiasing, and LOD easy. The drawback is the huge amount of memory required to store voxels, even with empty space compression. Still, GigaVoxels [Crassin et al. 2009] showed that by using a ray-guided cache to produce and store only visible voxels bricks on demand, it is possible to walk through very large and detailed worlds with real-time performance in bounded GPU memory. However, on-demand production of data during rendering is still challenging in terms of synchronization and starvation of GPU cores. We propose a new GPU-driven algorithm using dynamic parallelism (DP) to minimize these, and a "GPU-cores timeline" profiling tool to analyze them. We validate our model with timings (2× gain) and we illustrate it on various scenes.