Multi-Layer Alpha Tracing

Abstract

Rendering many transparent surfaces in real-time is still an open problem. We introduce two techniques for fast transparency rendering with ray tracing hardware, one being exact and the other being approximate but of high quality. Our approximate technique is called Multi-Layer Alpha Tracing, operates in bounded memory and is up to 60% faster than naive ray traversal. It outperforms existing rasterization techniques in terms of image quality and performance while maintaining a small memory footprint. It can also be used to accelerate ray tracing of transparent objects for the reflected rays.