Dynamic Volumetric Cloud Modeling,Real-time Rendering,and Acceleration Method On Mobile

In the field of computer graphics,natural scene simulation is one of the important research topics,and cloud simulation is an important part of natural scene simulation.With the improvement of computer performance,people have higher and higher requirements for simulation.Cloud simulations must be highly realistic,real-time,dynamic,and interactive.Cloud simulation is divided into two sections: modeling and rendering.The modeling section will build a model that describes the characteristics of the cloud.The rendering section calculates light and shadow based on modeling and draws clouds on the screen.There are two cloud simulation methods: based on physical models and based on empirical models.The former simulates actual physical activities in the cloud and has realistic effects,but the amount of calculation is huge and cannot be displayed in real time.The latter uses mathematical models to summarize and construct the characteristics of the cloud.It can be rendered in real time.The quality of the effect depends on the model itself and subsequent renderings.A good model and rendering method is important for real-time simulation of the cloud.Therefore,this paper proposes a cloud modeling and rendering method based on volume rendering.The main content of this article includes three aspects:The first is to propose a volumetric cloud modeling method based on noise generation.This method is based on type noise generated by Perlin noise and Worley noise,and combines a density height function and a time function to generate the volume field to model the cloud.The cloud is dynamic and high-fidelity,and can be used for multiple types of low cloud etage at the same time.The second is to propose a volumetric cloud rendering method based on Ray Marching.This method combines Beer-Lambert's law,phase function,and dark edge effects to calculate lighting.An optimized Ray Marching algorithm is used to render the cloud in real time.The effect of clouds is realistic,while the lighting is more realistic.The cloud movements and interactions can be simulated in real-time.The third is to propose a method for accelerating volumetric cloud on the mobile.This method models the volume field of a volumetric cloud based on a density estimation function generated by the polygon model and a turbulence noise generated by the Value noise.It uses an optimized Ray Marching algorithm based on the polygon model,and uses shadow maps to accelerate shadow rendering.A realistic dynamic volumetric cloud can be rendered in real-time on the mobile,which can simulate the movements of the cloud and the interactions with the shallow cloud.