Research And Implementation Of Simulation Methods For Realistic Snow Scenes

One of the research hotspots is the realistic modeling and rendering of snow scenesand other complex natural scenes in computer graphics and virtual reality field. Snowscenes simulation is widely used in virtual reality, video animation, computer games,etc. Moreover, the amount of snow deposited in the snow scene simulation predicted forthe prevention and treatment of heavy snowfall and the possible excessive snowsnowstorm also have a certain value.This thesis further makes the study of the latest research methods of the snowscenes simulation. According to the advantages and disadvantages of the particle system,this thesis puts forwards a method which combines LOD and the ground height fusiontechnology for simulating realistic snow scenes. The method optimizes snow transmitter,improves the effect of accumulation and melting of snow, and advances the efficiencyof the stability deposition of snow algorithm. The main work and the contribution ofthis thesis are as follows:1). In the stage of snowfall, for the problem that the effect of the transition is notenough natural using the method based on particle system and LODtechnology, the thesis improves a multi-level authenticity snow scenesimulation methods to enhance the authenticity of simulation results. Thismethod divides sky snow emitter into a number of small emitters,superimposes part area of the adjacent layer to achieve the effect of thetransition natural and realistic. Experimental results show that this method caneffectively describe the regional distribution of the snow particle shape, size,movement, and so on. And it achieves the snow simulations effect which has astrong sense of reality and have a certain hiberarchy.2). In the snow cover stage, for the question that the simulation effect ofaccumulation and melting process of snow is not enough realistic, the thesispresents a method that the sky snow particle emitters and ground snow particleemitter fire snow particles to simulate snow accumulation at the same time.The method adds a ground snow emitter independent of any sky snow emitterto simulate snow accumulation and melting effect, covered with sky snowparticles emitted “new” snow to simulate snow accumulation and meltingeffect. The experimental results show that this method can get the natural andrealistic simulation effect of accumulation and melting snow.3). In the snow deposition simulation stage, for the problem that large numbers ofparticles may lead to poor real-time, the thesis realizes a stability depositionmethod for the real-time smooth surface for large-scale snow scenes. Thismethod uses the ground height and simple random function to simulate the randomness of the snowfall location and depositional movement. Theexperimental results show that this method has a good real-time simulation ofmassive snow scene.4). Using the above research results, this thesis final designs and completes arealistic prototype system to simulate snow-scene, which can simulate snowscenes of different sizes by adjusting the sizes of temperature, humidity orsaturation. Experimental results show that the final results are true and realgood to verify the accuracy and effectiveness of the above methods.