Real-time Realistic Voxel-based Rendering

Abstract

With the advance of graphics hardware, setting 3D texture as render target is newly available to allow voxelization algorithms to record the existence, color and normal information in a voxel directly without specific encoding and decoding mechanism. In this paper two new voxel-based applications are proposed to take advantage of this new functionality for interactively rendering realistic lighting effects including shadow of objects with complex occlusion and refraction and transmission of transparent objects. An absorption coefficient is computed according to the number of surface drawing in each voxel during voxelization and used to compute the amount of light passing through partial occluded complex objects. The refraction and transmission of light passing through transparent objects is simulated by our multiple refraction algorithm using surface normal, transmission coefficient and refraction index in each voxel. All these applications can generate the result in real-time without any preprocessing step. Additionally, we also found that the newly available geometry shader can be used to transform a highly complex surface-represented scene into a set of high-resolution voxels in only one GPU pass. This possibly improve the efficiency of the voxelization process.