CloudLight: A System for Amortizing Indirect Lighting in Real-Time Rendering

This paper describes the CloudLight system for computing indirect lighting asynchronously on an abstracted, computational "cloud," in support of real-time rendering for interactive 3D applications on a local client device. We develop and evaluate remote-rendering systems for three different indirect illumination strategies: path-traced irradiance ("light") maps, photon mapping, and cone-traced voxels. We report results for robustness and scalability under realistic workloads by using assets from existing commercial games, scaling up to 50 simultaneous clients, and deployed on commercial hardware (NVIDIA GeForce GRID) and software (OptiX) infrastructure. Remote illumination scales well enough for deployment under each of the three methods; however, they have unique characteristics. Streaming irradiance maps appear practical today for a laptop client with a distant, rack-mounted server or for a head-mounted virtual reality client with a nearby PC server. Voxels are well-suited to amortizing illumination within a server farm for mobile clients. Photons offer the best quality for more powerful clients.