Hash-Based Hierarchical Caching and Layered Filtering for Interactive Previews in Global Illumination Rendering

• Main Authors: Thorsten Roth, Martin Weier, Pablo Bauszat, André Hinkenjann, Yongmin Li
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Computers
• Subjects: ray tracing; global illumination; level-of-detail; caching; rendering
• Online Access: https://www.mdpi.com/2073-431X/9/1/17

Modern Monte-Carlo-based rendering systems still suffer from the computational complexity involved in the generation of noise-free images, making it challenging to synthesize interactive previews. We present a framework suited for rendering such previews of static scenes using a caching technique that builds upon a linkless octree. Our approach allows for memory-efficient storage and constant-time lookup to cache diffuse illumination at multiple hitpoints along the traced paths. Non-diffuse surfaces are dealt with in a hybrid way in order to reconstruct view-dependent illumination while maintaining interactive frame rates. By evaluating the visual fidelity against ground truth sequences and by benchmarking, we show that our approach compares well to low-noise path-traced results, but with a greatly reduced computational complexity, allowing for interactive frame rates. This way, our caching technique provides a useful tool for global illumination previews and multi-view rendering.