Surface Mesostructure Modeling And Hardware-Accelerated Rendering Techniques Research

In real world, there exists a lot of mesostructure on object surface which is between the scale of microstructure and mesh. The appearance of real world object is largely determined by its surface mesostructure, which leads to visual effects such as fine-scale occlusion, silhouettes, shadowing and interreflection under local and global illumition.However, there are two challenges to modeling and rendering the surface mesostructure by conventional methods of computer graphics. Firstly, the geometry and albedo of surface are hard to be precisely captured. Some methods have been introduced. However, all of them are lack of robustness so far and too complex to be generalized among artists who do not have much background knowledge of graphics. Secondly, decorating mesostructure upon gross surface will dramatically increase the complexity of geometry. If it is directly represented by triangle, there should be millions of triangles which need to be sent to hardware for rendering. It consumes large amount of memory and can not achieve real-time performance in contemporary graphics hardware.In this paper we present an approach for realistic modeling of surface mesostructure and efficient rendering of the associated visual effects under both local and global illumination. For modeling, we present an appearance-based method to model the geometry of mesostruture from single representative image. With our intuitive and easy-to-use user interface (UI), the height field of mesostructure can be assigned in several minutes. For rendering, we introduce two techniques called view-dependent displacement mapping (VDM) and generalized displacement mapping (GDM). VDM can only render height field, however, GDM can handle any mesostructure represented by volumatric texture. Both VDM and GDM allow for efficient rendering of shadowing, occlusion, and silhouettes without increasing the complexity of the underlying surface mesh. They are based on per-pixel processing and with hardware acceleration it can render mesostructure with rich visual appearance of local and global illumination in real time.