A distributed pipeline for interactive physically based rendering

Abstract

The synthesis of virtual environments using physically based approaches re- quires high-end machines, even for dynamic scenarios that are moderately complex in terms of geometry and illumination. The constraint of interactivity further compounds these requirements, especially when large output resolutions are taken into consideration. In order to democratise physically based rendering and make it available to a wide spectrum of devices, from mobile to tablet to desktop machines, a distributed graphics pipeline is proposed that enhances traditional GPU-based real-time graphics with the computational power of the Cloud. A prototype of the proposed pipeline is presented. In the fi rst stage of the implementation, the computation of indirect light within the global illumination rendering pipeline is relocated to a precomputation stage and merged with the direct light image at the post-processing stage. In this stage the computation is performed on the target machine itself. In the second stage, the computation of indirect light is moved to the Cloud and applied to static scenes. Finally, in the third stage, support is added for dynamic scenes, with experiments performed on moving lights. This study demonstrates that such a distributed pipeline is viable, with good quality images obtained at high frame rates on the client. The proposed pipeline also scales well when servicing multiple clients simultaneously.