Single-Scattering and Multi-scattering in Real-Time Volumetric Rendering of Clouds

The aim of this work was to design an algorithm for rendering volumetric clouds in real time using a voxel representation. The results were verified using reference renders created with the Blender program using the Principled Volume shader. The important properties of the algorithm that were tried to be achieved are the ability to display clouds with different characteristics (thin and dense clouds) and the speed of operation enabling interactivity. We proposed a method consisting of two parameterizable image display algorithms with various performance and properties. The starting point was the single-scattering algorithm, which was extended with precalculation, and a simplified form of multi-scattering. Individual methods were compared with reference images. Methods performing similar tasks, depending on the purpose, generate single image frames at a rate ranging from several dozen hours to a few seconds. Using the described mechanisms, the proposed method allowed to achieve times between 1 and 200 milliseconds, depending on the method variant and quality settings.