Geometry-Shader-Based Real-time Voxelization and Applications

This work proposes a new real-time voxelization algorithm based on newly available GPU functionalities and designs several applications to render complex lighting effects with the proposed voxelization method. The voxelization algorithm can efficiently transform a highly complex scene in surface representation into a set of voxels in one GPU pass using the geometry shader. The surficial and volumetric properties of objects such as opaqueness, refraction and transmission are directly recorded with newly available 3D textures. The usage of 3D textures can remove those strenuous efforts required to modify the encoding and decoding scheme when adjusting the voxel resolution. In the first, surficial and volumetric properties recorded in 3D textures can be used to interactively compute and render more realistic lighting effects including the shadow of objects with complex occlusion and the refraction and transmission of transparent objects. The shadow can be rendered with an absorption coefficient which is computed according to the number of surfaces drawing in each voxel during voxelization and used to compute the amount of light passing through partially occluded complex objects. Second, the surface normal, transmission coefficient and refraction index recorded in each voxel can be used to simulate the refraction and transmission lighting effects of transparent objects using our multiple-surfaced refraction algorithm. Finally, the results demonstrate that our algorithm can transform a dynamic scene into the volumetric representation and render complex lighting effects in real time without any preprocessing.