Methods for Calculating and Visualizing the Spatial Distribution of Illumination in Three-dimensional Models of Optically Complex Scenes

Abstract

In this paper, we consider the problem of calculating the effective protection of an image from spurious radiation, one of the causes of which is the scattering of light on non-imaging elements of an optical device. The purpose of this work is to improve the means of searching and visualizing the sources of parasitic illumination of an image for designing and analyzing the light protection of optical devices. A visualization of the spurious radiation illumination distribution on the surfaces of an optical device is proposed. The global illumination calculation is based on an advanced bi- directional stochastic ray tracing method with backward photon maps. This method is highly efficient, since it simultaneously uses direct and backward photon maps, which accumulate the distributions of the areas of light emission and the visibility of the scattering elements of the optical device, respectively. The method allows representing the average illumination of the image, accumulated on the diffuse objects of the optical device that form the given illumination. By visualizing it, you can more effectively and clearly find the elements of the optical device that create spurious illumination in the image and degrade the image quality. With this information, the designer of an optical device can develop special means of light protection or use special light- absorbing coatings for such elements. The proposed algorithms were implemented in the Lumicept software package, with the help of which the scattered light in the lens objective was calculated and the result of the stray illumination visualization was presented.