Research On The Simulation Of The Interaction Of Snow Particle And High-Speed Object In 3D

With the development of computer hardware, people need computer games with high fidelity in game screen. In order to enhance the fidelity of the screen, various natural phenomena are being added to game scenarios, for example:fog, rain, snow and so on. Although snow has appeared in computer games, it just renders static scenario covered with snow or falling snow, it has not processed the interaction of snow particles and high-speed objects. The study of the interaction of snow particles and high-speed objects can make us simulate the world in game more naturally, and make us create games with more reality.The interaction of snow particles and high-speed objects is very complex, so we break it down into three modules:the snow generation module, the snow particles dynamic module and the window field of high-speed object module, and study it separately. In the stage of snow particle generating, we study the algorithm of the triangular polygon snow texture generating algorithm, because it cannot generate good quality texture, we smooth snow edges with Quadric Bezier Curve in order to generate snow textures with more realistic. In the stage of snow particle dynamic, there are four kinds of force used in snow particles:gravity, buoyancy, swaying force and centripetal force. Combining with Newton's Second Law and the snow particle's natural properties, we can compute the position and velocity of the snow particle. Because the swaying force of snow particle and wind speed are related, and the swaying force has very important influence on the movement of snow particle, so we study the wind field on the top of high-speed object. Wind field is simulated by Navier-Stokes Equation which is solved by the Semi-Lagrangian method. The simulation of wind field is divided into three parts:discretisation, convection step and projection step. A simple wind field model of high-speed object is found finally. We combine three sub-models into one model of the interaction of snow particles and high-speed objects. Then we discuss the setting of some paraments and accidents about every model.Simulating the interaction of snow particles and high-speed object must have something with snow accumulation model and collision detection, so we discuss the algorithm of how to render accumulating snow additionally. The algorithm first evaluates the snow accumulation prediction function, then calculate the color of the snow. The time complexity of collision detection system is very big, we add activity property to every leaf node of the BSP on the base of the hierarchy of bounding box to accelerate the efficiency of collision detection. At last we combine it with the LDI algorithm to detecte collision quickly.