Efficient volumetric ray casting for isosurface rendering

While volume rendering is becoming more widely used in medical applications, it is still difficult to generate a good quality image interactively without expensive hardware when the size of the dataset is quite large. For interactive rendering of a large dataset, we present an acceleration method, image-space bounding surface. Using an image-space bounding surface, the isosurface ray casting is accelerated by avoiding unnecessary volume traversals. Image-space bounding surface can be interactively handled by polygon rendering hardware even in a conventional personal computer. Two optimization techniques, LF-minmax map and memory bricking, are also employed to efficiently render isosurfaces. This paper also shows that the algorithm can be extended to multiple isosurfaces rendering. The experimental results show that the algorithm generates a good quality image of a large dataset interactively on a standard PC platform.