Reducing Computational Complexity of Real-Time Stereoscopic Ray Tracing with Spatiotemporal Sample Reprojection

Sample reprojection is a computationally inexpensive way of increasing the quality of real-time ray tracing, where the number of samples that can be traced per pixel within the time budget is limited often to just one. Stereoscopic rendering further doubles the amount of rays to be traced, although it exhibits significant correlation not only temporally between frames, but also spatially between the viewpoints of the two eyes. We explore various reprojection schemes taking advantage of these correlations, and propose to quantify their contributions on the improved quality in terms of effective sample per pixel counts. We validate that sample reprojection is an effective way of reducing the computational complexity of real-time stereoscopic ray tracing, bringing potential benefits especially to lower-end devices.