Interactive Two-sided Refraction for Dynamic Object on GPU

This paper introduces an approach to interactively compute two-sided refraction on GPU and gains comparable realistic effects with ray tracing, while most current interactive techniques are restricted to single refraction. Our approach is also efficient for total internal reflection (TIR). When processing rigid movable object, we render the object's normal to a cube map first before entering the render loop. And for deformable object, the object's normal is rendered to a cube map at each frame. Then we compute the back interface refraction point by binary search in fragment shader. At last the refracted color is determined by indexing into a distant environment cube map using the second refracted ray as texture coordinate. Because our approach can fully exploit the capabilities of GPU, it achieves realistic refraction results and interactive frame rate even for fairly complex objects on common PCs.