Research On Three-dimensional Vector Field Visualization Methods

In recent years, the research about three-dimensional information on the field of geo-science, including geology, hydrology, meteorology, fluid dynamics, geodesy, etc. is growing.3D visualization as the most intuitive and efficient way of get information has a unique advantage in express information. Vector field describes lots of very important and common physical phenomenon. Vector field visualization is a powerful tool to understand the laws of motion of the vector field and plays an important role in scientific computing and engineering analysis. It has been widely used in geological exploration, astronomy and meteorology, aerospace and other fields. With the rapid development of computational fluid dynamics, we urgently need a technology that can help researchers understand the law of large data sets. Especially in the Engineering Calculations,Earth Science, vector field researchers need to less time-consuming and better performance visualization methods.Visualization of three-dimensional vector field has always been the important and difficult to visualization. Currently, three-dimensional vector field can be described by Point icon method, Vector line, Vector surfaces, Vector tube Etc. Even though streamline and Point icon method can shown the trajectories of vector field in three-dimensional space, but it can't reflect the overall features of the vector field. Three-dimensional texture method proposed some solutions, but the rendering quality is relatively poor.In this paper, we used three-dimensional vector field data which produced by geosciences mechanism and process simulation, depended on the existing algorithms and implementations of three-dimensional vector field, and used the fusion expression and dynamic interaction method of three-dimensional vector field and scalar field, to realize the Real-time three-dimensional vector field dynamic rendering. At the same time,we adopt the technology of tetrahedral multi-resolution mesh adaptive generation to further improve the quality of three-dimensional visualization which expressed by the existing three-dimensional vector field visualization algorithm and bringing into effect of real-time three-dimensional vector field dynamic rendering.(1) Tetrahedral multi-resolution mesh adaptive generationAccording to the model calculation and visualization requirements, based on the research of discrete grid, we proposed tetrahedral multi-resolution mesh adaptive algorithm. The algorithm through the four steps, plane grid modeling, model geometry feature recognition, size control, model adaptive planar grid generation, tetrahedral multi-resolution mesh generation realize tetrahedral multi-resolution mesh adaptive generation. It was applied to the wind field and concentration field in Taihu Lake Three-dimensional visualization.(2) The fusion expression of three-dimensional vector field and scalar fieldWe mainly study the three-dimensional vector field visualization of streamline and streamsurface, and its integration of three-dimensional expression of the scalar field. We offer a variety of dynamic interactive model and it makes three-dimensional vector field and three-dimensional scalar field visualization more clearly, intuitive, interactive.(3) Prototype systemIn this paper, we used existing three-dimensional vector data visualization algorithms, Dotnet and VTK to build three-dimensional vector field visualization prototype system.Examples show that the proposed algorithm is reliable and efficient. It can be solved to some extent to the need of three-dimensional vector field data visualization in the process of geosciences mechanism and process simulation.