Research And Implementation On Key Techniques Based On Particle System In Process Simulation Scene

The shape of most sceneries in nature,such as clouds,fire,ocean waves,rain and snow etc.,changes with time past,and it is difficult to model and visualize the natural sceneries by using traditional methods.So the simulation of natural sceneries becomes a hot topic in the research field of Virtual Reality Simulation.In this thesis it is dedicated to research on the simulation of trail fire,exploration,rain, snow and smoke.So it introduces the basic theories of the particle system and implements the simulations of trail fire,exploration,rain,snow,smoke and dynamical simulated in real-time using particle system.In this part,it is presented a survey of some existing algorithms of their simulation by domestic and international scholars at the beginning. Then their definition and character are introduced.On the premise of visual realism of trail fire,exploration,rain,snow and smoke and real-time implementation,the algorithms for simulating real-time them based on particle system are proposed.For decreasing the implementation time,the positions of new particles are initialized with random numbers. And based on the analysis of the motion of these particle systems,those complex motion fields of them are simplified to four simple-motion fields.Thus the implementation velocity is enhanced,and real time simulation becomes possible.In order to make the smoke-spreading situation more living,it is given a collision detection method of smoke spreading in complex environment,witch don't only achieve the collision detection of smoke particles in spreading but also changed the movement situation of the smoke particles automatically and it avoided setting conditions artificially.Furthermore,we use surface particles instead of dot particles to render trail fire,exploration,rain,snow and smoke,so the implementation time is further decreased.And we also use texture map technique,billbord technique and display lists technique to enhance the render quality.At last,this paper develops and implements a demo system,by which it can test the algorithms based on particle system given in this paper.And it deeply discussed how to construct 3D terrain,how to construct 3D sky,how to construct 3D substances,and how to interactive control.Experimental results show that our algorithms can produce real time simulation in consumer PC Platform and the effect looks realistic,and these algorithms can be applied widely to virtual scene in games,movies and TV programs.