GPU BASED GLOBAL RENDERING VIA IMPORTANCE DRIVEN ENVIRONMENT MAP SAMPLING
In some real time applications such as 3D games and virtual reality, it has to produce interactive rendering of global illumination for different objects. Global illumination (GI) has very complex lighting condition such as diffuse light, inter reflection and soft shadows, which is difficult to simulate GI. In this paper, we propose the GPU (Graphics Processing Unit) based global rendering via importance driven environment map sampling. We use HDR (High Dynamic Range) environment map to efficiently represent complex global illumination, which is usually capable of GPU implementation. Based on the importance driven sampling points around bright areas, we obtain fewer but more important illumination points to simulate global illumination. Global rendering equation is deduced and the discretization is acquired using the two pass algorithm of photon mapping via CUDA (Compute Unified Device Architecture) acceleration. Finally, the results show that we acquire realistic effects of rendering such as inter reflections, luster, caustics and soft shadows, while keeping an interactive rendering speed.