为实时绘制真实感的云场景,针对已有基于网格的方法效率低下的问题,提出动态网格方法,充分考虑风对云的发展变化的影响。在动态网格上离散化云的运动方程和热动力学方程,根据视距的变化调整网格分辨率。在云的绘制过程中,将Cornette-Shanks相位函数用于多重前向散射模型,并采用GPU加速来提高仿真效率。实验结果表明,提出的动态调整网格分辨率的方法提高了仿真效率,可以实时模拟云与物体的交互和绘制真实感的云图像。
In order to render photorealistie clouds scenes in real time, this paper developed the dynamic grids method to address the problems of inefficiency in the existing grid-based methods. It took full account of the role of the wind. It discretized the equations of motion and thermodynamic equation on the dynamic grids, and adjusted the resolution of simulation space according to the change of sight distance. During rendering the clouds, it applied the Cornette-Shanks phase function to the multiple forward scattering model. At the same time,it fully utilized the parallel computation performance of GPU. The experimental results show that the proposed method of dynamically adjusting grid resolution has high efficiency, and can simulate the interaction between clouds and the objects and render realistic clouds in real time.