Ray Tracing

Ray tracing calculates how simulated light rays interact with scene geometry and materials. In games, it can improve reflections, contact shadows, ambient occlusion, transparency, and global illumination beyond many screen-space or precomputed techniques. Real-time ray tracing is computationally expensive, so engines trace a limited number of rays, use acceleration structures, combine results with rasterization, and apply denoising or upscaling. Hardware support improves performance but does not make every effect free. “Path tracing” generally refers to a more comprehensive, multi-bounce approach that targets greater physical accuracy at a much higher cost.