Subtopics geometrical optics acceleration structures BVH ray marching object intersections rendering equation Integration Algorithms whitted ray tracing path tracing Monte Carlo Integration Monte Carlo integration Variance Reduction importance sampling multiple importance sampling next event estimation - direct lighting with shadow rays for fast convergence Russian Roulette GPU Ray Tracing wavefront path tracing RTX ray tracing pipeline ray query shader binding table Ray Tracing APIs Optix Vulkan ray tracing