Efficient Synthetic Light Field Rendering on Heterogeneous Systems Using a Pipeline-Based Runtime Design

The research interest of real-time global illumination has increased due to the growing demand of graphics applications such as virtual reality. Recently, the design that combines Image-based rendering (IBR) and Ray-Tracing to create Synthetic Light Field (SLF) has been widely adopted to provide delicate visual experience for multiple viewpoints at an acceptable frame rate. However, despite its parallel characteristic, constructing a SLF is still inefficient on modern Graphics Processing Unit (GPU) due to the irregularities. For instance, the issues caused by branch divergence, early-termination and irregular memory access prolong the execution time that cannot be simply resolved by workload merging. In this paper, we proposed a Runtime design that reorganizes the execution into a pipeline-based pattern with grouping of primary rays. With this approach, the number of valid rays can be maintained at a high level with less divergence of paths. Based on the experiment on a heterogeneous system, the throughput becomes 2.48 times higher than the original on average.