Real-time Rendering For Trees Based On Programmable Rendering Pipeline

3D Visualization Technology is walking into many fields of different industry and research by the dramatically improvement of computer science, such as aerospace, military and medicine. As a key point of 3D Visualization, real-time rendering have being always in hot spot and how to fully utilize the technology is the dark clouds in many researchers’minds. In other aspect, with the forestry developed,3D Visualization been used in forestry research is a trend because the advantages of 3D Visualization in performance ability, expression ability and display ability. Also, this paper has something meaningful to the research of Forestry subsequent development in 3D Visualization.In current forestry 3D researching, real-time rendering techniques are in the elementary level; almost applications are using the fixed rendering pipeline, which has decades of history, to perform the computer virtual world, and currently the programmable rendering pipeline is leading the area. On the other hand, in different purposes, real-time rendering in other else field have flaws and difficulties to apply into forestry. So this paper is focus on the real-time rendering in forestry and the research in the paper would try to get some useful ways to help the 3D visualization in the tree stands, by improving the performance, improving the effectiveness and then trying to find a good way to do this all. All the processes will run in the GPU in a unique way and is based on the dates of exited achievements. The goal will be displayed as these three ways.First study is, in materials, normal mapping, which can improve the performance of real-time rendering in details with keeping a balance in effect and runtime. This paper provided a method to create normal texture of tree barks from its gray scales image. Using the texture as a light intensity data, and after local curve fitting, differential, getting normal, the normal texture of our own can be got. And this texture can implement our normal mapping. Normal mapping in Tree Stand Visualization is a effective way to improve the level of tree materials and itself.Second study is researching on the terrain modeling of tree stand district. This paper provided a method for terrain modeling by two-dimensional Gaussian template, and overcame a load of problems in traditional interpolation modeling. As the steps by samples collection, information analysis, gray scale data, template setting, calculating and getting result, this new way to modeling can solve issues of terrain building in computer.Finally, this paper focused on the light radiation in global illumination. The method is to simulate the global light distribution in an area according its reflection, refraction and scattering. This paper proved a method for the tree stand global illumination in light radiation, based on environment of tree stand including trees, leaves, ground and so on, and focus on how to improve the performance and effect of tree stand real-time rendering procedure.At the last, the study of the paper could be spread its achievements and methods to other field else. One reason is that the flexibility of real-time rendering itself and the other is that extra consideration in scalability in our studying.