Synthesis methods for realistic images of three-dimensional scenes containing media with a refractive index gradient

The paper presents the results of a study of the possibility of implementing an effective and physically correct stochastic ray tracing in gradient media based on the Runge-Kutta method. For implementation in the photorealistic rendering system, the specifics of the ray tracing method in complex three-dimensional scenes were considered. One of the main features of ray tracing in geometrically complex scenes is the large volume of geometric primitives that need to be tested for the intersection of the ray segment with the primitives. A method of ray propagation in voxel space of the scene is proposed. The method allows significant speeding up the process of searching for ray intersections with geometry primitives. To implement these ray tracing features the special program interface for gradient media was proposed, which can become the basic interface for a media of all types. Methods for calculating the luminance of all lighting components in gradient media were considered. The results of modeling the propagation of rays and image synthesis in a fiber with a refractive index gradient are presented.