Texture Slab Projection and BSP tree for GPU Accelerated Volume Rendering

An improved method using graphics processing unit (GPU) is proposed for ray casting algorithm because of large volume data and slow speed in volume rendering. The algorithm combines texture slices to form texture slabs, and codes texture slabs with BSP tree, then, projects the slabs and renders nonempty slabs from front to back. Because of texture slab projection includes information of empty region, full region and early ray terminated region of volume data, so accelerated volume rendering can be achieved through texture slab projection along the ray direction. Texture slab projection is created on the fly by GPU without any pre-processing time, and the creation time of BSP tree is still small in relation to the whole volume rendering. The experiment results show that this method can speed up average 3.41 times of volume rendering on GPU and achieve good rendering effects.