Visualization Of Time-Dependent 2D Vector Fields Based On Topological Method

As an important and intensive subject of research in visualization in scientific computing, vector field visualization is widely applied CFD (Computer Fluid Dynamics) etc. In the vector field, traditional visualization method only display vector distribution nearby special point, it did not reflect entirely structure of vector field. Topological method is feature visualization with extract critical point and display entirely structure of vector field. We study visualization of time-dependent 2D vector fields based on topological method.Firstly, we research on vector line visualization. Traditional closed streamlines detection was dependent on grid. An improved method was proposed. It tracked critical point with feature flow field and integrated stream surfaces with saddle connector according to the direction of eigenvector of Jacobian matrix to closed streamline.Then, we also research on vector surface visualization. To resolve the issue caused from discrete integration of stream surfaces and discontinuity of mapping while detecting separation surface, an improved method was proposed. It apply Sobel operator in detecting seeding curves and integration of seeding curves to surfaces.The results demonstrate that closed streamlines detection and visualization solve the defect of dependent on grid. The algorithm track critical point, so that closed streamline is detected at first step. It can detect closed streamline with particular time-step. Separation surface detection and visualization solve the problem of discrete integration of stream surfaces and discontinuity of mapping. The scheme is valid in vector field visualization. .