A method for modeling volumetric clouds and subsurface scattering of functionally specified objects

Abstract

Accurate modeling of light transfer in media is important in many fields, such as scientific visualization, medical imaging, synthesis of realistic images, and so on. Complex volumetric structures and translucent materials are used. Light scattering in media is responsible for the appearance of many materials. However, accurate and efficient modeling of lighting effects is a difficult problem. This requires solving not only the visualization equation, but also its volumetric solution, the radiation transfer equation. A method for modeling subsurface scattering of functionally specified objects is presented. The method allows you to simulate the transfer of light in chromatic media. To do this, a modified free-range distribution is used. This allows you to minimize the deviations of the bandwidth of the path. As a result, the variance of the estimate is reduced. The collision coefficients depending on the wavelength are effectively processed. As a result, it is possible to simulate volumetric clouds and subsurface light scattering in translucent materials such as marble, wax, leather, etc. The control coefficients and free run sampling are based on the minimum and maximum values in the media found by random sampling over a short preliminary pass. Reducing the rendering time is achieved by using a different distribution of paths.