一种快速高效渲染水下刻蚀和光束的方法

Fast and Efficient Rendering of Underwater Caustics and Light Shafts

为了快速渲染大面积水域的水下刻蚀及光束,将刻蚀图技术引入水下光照的渲染,结合FFT水面的周期性对刻蚀图进行改进。采用物理光学方程估算光子到达水下某深度时的强度,从光源视角以点图元渲染光子构造刻蚀图,然后通过投影纹理技术渲染水下地形的刻蚀,利用光线行进技术渲染水下光束,光束和刻蚀的渲染都是基于对刻蚀图的采样,且全部在GPU中执行。该方法易于实现,效率高,适合交互式应用。

In order to render caustics and light shafts of a large area of water fast, a caustics map technique was introduced into underwater rendering. This technique was improved with the advantage of periodicity of FFT water. The intensity of every photon underwater reaching a certain depth was physically approximated. Photons were then rendered as point primitives from the light＇s point of view to form the caustics map. The techniques of projective texture mapping and ray marching were used to render underwater caustics and light shafts respectively. The renderings of caustics and light shafts are both based on sampling the caustics map and run entirely on the GPU. The method is efficient, easy to implement and fit for interactive applications.