Efficient Splatting Using Modern Graphics Hardware

Interactive volume rendering for data set sizes larger than one million samples requires either dedicated hardware, such as three-dimensional texture mapping, or a sparse representation and rendering algorithm. Consumer graphics cards have seen a rapid explosion of performance and capabilities over the past few years. This paper presents a splatting algorithm for direct volume rendering that utilizes the new capabilities of vertex programs and the OpenGL imaging extensions. This paper presents three techniques: immediate mode rendering, vertex shader rendering, and point convolution rendering, to implement splatting on a PC equipped with an NVIDIA GeForce4 display card. Per-splat and per-voxel render time analysis is conducted for these techniques. The results show that vertex-shader rendering offers an order of magnitude speed-up over immediate mode rendering and that interactive volume rendering is becoming feasible on these consumer-level graphics cards for complex volumes with millions of voxels.