Ray Tracing Algorithm Based on Screen Space Ray Marching

Abstract

Ray tracing is a very important operation in modern computer graphics which enables photorealistic rendering with advanced level of accuracy in simulating light transport and interaction with geometric objects. By tracing the path of individual light rays and determining how they bounce through the environment, rendering engines produce highly detailed and precise reflections, shadows, refractions and global illumination, which significantly enhances visual fidelity. This technology is an integral part of computer simulation and modeling software packages, animated films and cinematic effects production software and also computer games and other interactive graphics applications where the demand for realistic visuals continues to grow. Recent advancements in graphics hardware capabilities including hardware ray tracing support introduction increased ray tracing performance significantly. However, ray tracing remains a significant bottleneck in a majority of algorithms used in modern rendering engines. Due to that, ray tracing optimization is an important research direction nowadays.

This work is aimed at development of the screen space ray marching implementation capable of correct determination of the valid ray tracing query result when environment geometric information stored in the depth buffer is sufficient to guarantee it. The implementation of this method is presented that is both efficient and provides good precision of the results. Experimental testing is performed to validate the results and measure the performance of the implementation. Based on these observations, we prove the benefit of using our implementation in the hybrid ray tracing system, which runs screen space ray marching method to avoid executing costly hardware ray tracing for all the rays to be traced.