Fast global illumination of dynamic water surface based on two stage rendering

Water simulation plays an important role in computer graphics, and its complex optical properties are very computationally intensive due to the variation of phenomena. In this paper, a fast-global illumination method of dynamic water surface with precise reflection and refraction is proposed using a two-stage rendering strategy. At the first stage, we generate an improved Secondary Texture Map (iSDT) based on the distortion of Perlin noise. Our method generates octaves of Perlin noise to construct random height of water surface. For fast rendering the reflection, we utilize 2D mesh modelling water surfaces and optimize the uniform mesh of surface by a layer of detail approach. A 3D geometries’ mirror reflection with respect to 3D perspective view is computed and stored as a texture map. Then the texture map is distorted by octaves of Perlin noise. At the second stage, we combine the iSDT with ray tracing strategy for computing global illumination above the water surface. Experimental results show that our method reduces the rendering time compared with the original ray tracing, and both the opaque and transparent geometries are rendered with plausible high-quality with correct reflection and refraction.