The paper presents a simulation and rendering model of three dimensional covective cloud evolution. The model is physically based, however its purpose is graphical. The main stress is put on balancing two parts of a model: the atmsphere simulation with convective motion of air and water vapor combined with rendering of semi-transparent and light-scattering clouds, in order to achieve realistic animation in real-time. We examine and compare two algorithmic approaches based on CPU and GPU computations.
In the paper we present a method of direct access to single blocks of JPEG files which contain textures, with on-the-fly decompression. Anisotropic, adaptive filtering is applied in order to minimize visual defects appearing mainly on blocks borders. Main purpose of the method is to enable fast extraction of only these parts of an entire image which arę currently needed and not to keep whole decompressed texture in the main memory. This approach enables effective usage of high quality textures with Iow memory consumption. It's benefits are mainly demonstrated in rendering complex 3D scenes using nondeterministic ray-tracing algorithm. The algorithms have been encapsulated into DLL and static library.
