| Recently,3D Games,VR and comics and animation industry has been developing rapidly.People also have more and more requirements on fidelity of simulate images.Among all the simulations,the natural scene simulation has always been the most hot and difficult field due to its complex modeling and rendering.Clouds are one of the most common landscapes in the natural,and the cloud simulation technology is endless.But the problem is that clouds’ shapes and color are always changing.Considering that how to choose the right model and improve the simulate efficiency has always been the key to cloud simulation.This thesis present a physically-based,visually-realistic cloud simulation applications.In all kinds of physically-based simulation systems,it is difficult to solve the efficiency of simulation,when the simulation scale is expanded.To solve this problem,my cloud simulation system have CPU and GPU parts.The CPU only init the system and control the process.The GPU is responsible for the computering and rendering.This thesis use OpenGL and particle systems to model clouds in the sky.Clouds in the system are modeled using partial differential equations describing fluid motion,thermodynamic processes,buoyant forces,and water phase transitions.This thesis also simulate the interaction of clouds with light,including self-shadowing and multiple forward light scattering.This thesis implement both simulations,dynamic and radiometric,entirely on programmable floating point graphics hardware.The speed and parallelism of graphics hardware enables simulation of cloud dynamics in real time.Finally,the cloud simulation system draws real-time and realistic clouds. |
