Study On Real-time Interaction Improvement Of Smoke And Obstacles Based On Overlapping Grids

The smoke simulation has been frequently used in various simulations and is still a challenging problem today. This project is supported by the National High Technology Research and Development Program of China(No. 2009AAXXXXX) and the National Natural Science Foundation of China(No.60970073). According to the factor that affects the reality and the real-time of the smoke simulation, this paper focused on the following aspect. Firstly, we simulate smoke that interacts with obstacles to improve the reality of simulation, and introduce the node-grouping method to process the boundary condition of the obstacles. We first group all of the grid nodes into different types according to their different orientations to the obstacles, and then utilizing different types of the grid nodes, we deal the flow of the smoke around the obstacles. By using the node-grouping method, we can process arbitrary boundary condition of the obstacles and satisfy the demand that smoke interacts with complex obstacles.Secondly, smoke ususlly needs to interact with large numbers of obstacles in the complex scene. However, it is time consuming for smoke to interact with obstacles in the high resolution grid. To improve the visual details around obstacles and ensure the real-time of the simulation, we introduce the overlapping grids method. We surround a local grid around each obstacle to capture the visual details and meanwhile maintain the real-time of the simulation. We then propose a novel method to dynamically contral the resolution of the local grid. The complex degree of the obstacle's shape, the distance between the local grid and the viewport, and the turbulence of the smoke are used together to determine the resolution of the local gird during the running process of the simulation system, by which we obtain rational resolution of the local grid and further enhance the real-time of the simulation. Finally, utilizing VC6.0 and OpenGL, we design and realize the Real-time Interaction System of Smoke and Obstacles to validate the effectiveness of our system in enhancing the reality and the real-time of smoke simulation, and we realize our system totally based on GPU. The experimental result shows that, by adopting the methods proposed, our system can precisely capture the flow details of the smoke around the obstacles and distinguishly increase the simulation speed of the tradional ovlapping grids method.