Simulation Of Dynamic Water Grass Based On GPU

Simulation of plants has always been a difficult and central issue in Computer Graphics. In recent years, the diversity of plants morphology has attracted more and more researchers while the complexity and fantasticality of underwater scenes has attracted more and more attention to simulation. As a kind of aquatic plants, water grass is an important natural landscape in underwater scenes, and the simulation of water grass in virtual reality has great significance.As a subsidiary project of "Virtual Taihu Lake" which is developed by some Supervising Department of Suzhou, the main task of this paper is to present a dynamic water grass simulation method based on GPU, Bezier curves and particle system theory. For modeling of water grass, the basic idea is to use the Bezier curves to generate the middle line and the edge of grass blade, build the grid of grass blade by the interpolation and triangulation to ensure the curl information and smoothness of the leaf, and then generate the whole grain water grass through the rotation and scaling transformation of the leaf, at last, in order to get closer to the natural state of water grass, the dark spot on the leaf is generated by using multitexturing. The paper uses the particle system theory to realize the dynamic effect of water grass, and the method takes the control vertice of grass blade as a particle, changes the shape of the leaf in real time by controlling the movement of these particles, and then obtains the dynamic effect of the water grass. Because the water grass group has a large quantity of control vertices, so we use CPU and GPU to simulate water grass in Taihu Lake in order to take full advantage of efficiency and parallel processing capabilities of GPU programming. Experiment result show that the method is feasible, and can greatly reduce the computation burden of CPU.We also simulated other scenarios. The bottom of lake is simulated by Catmull-Rom algorithm, which exponential decayed the underwater light. The paper achieves dynamic real-time simulation of water grass through the synthesis of the bottom of the lake, water grass, the dynamic effect, and the processing of lighting, fog. The project can meet the practical needs.