Physically-based Algorithm For Natural Rime Growth Simulation

With the continuous optimization and development of computer hardware devices and computer graphics,the realistic simulation of natural scenery has been greatly improved.At present,the simulation for natural scenes such as trees,grasslands and oceans has achieved real effects.It has been widely used in games,animation,forestry research,garden planning and other neighborhoods.Yet there is little study about simulating rime in computer graphics.Therefore,this paper selects the natural scene of rime for realistic simulation.Rime is a common natural landscape in winter,with high ornamental value,while under certain growth conditions,it will become a huge destructive power of natural disasters,endangering people's lives and property.An algorithm for rime growth based on a physically-based approach is proposed in this paper by analyzing the morphology of two kinds of rime(soft rime and hard rime)under different wind speed and temperature,which mainly simulates the morphology and growing direction of rime in different wind speed and temperature environments.First of all,the algorithm selected the growth points on the triangular surface of the model.Perlin noise is used to simulate wind field and the corresponding wind speed and direction of each growth point were calculated by taking the coordinates of growth points as parameters.At the same time,a smoothing function is added into the noise function to attenuate the unnatural effects.After that,the length of rime is calculated by using the conductor model established by the principles of fluid mechanics and thermodynamics.Finally,the diffusion-limited aggregation method is used to simulate the morphology of the soft rime by taking each growth point as a condensed nucleus and considering the influence of wind on particle agglomeration.The morphology of the hard rime was simulated by using the segmentation method by analyzing the force of the haze in the wind environment.The experimental results show that our method can simulate the soft rime and the hard rime in nature realistically and efficiently,especially for the details of the rime growth results.And has value of research and application in game,animation,virtual reality and natural disaster prevention.