Abstract: A volume data set composed of voxels is rendered onto an image plane composed of pixels by casting a ray through each pixel of the image plane. A surface of the volume data set is selected as a base plane. Sample points are defined along each ray so that the sample points lie in planes parallel to the base plane. Voxels adjacent to each sample point are sampled to determine a sample value for each sample point, and the sample values of each ray are combined to determine a pixel value for each pixel.

Abstract: A method corrects opacity values of samples in a rendering pipeline. The method partitions a range of uncorrected alpha values into a plurality of segments in a low to high order. Corrected alpha values for uncorrected alpha values in the highest segment are determined by direct table look-up. Corrected alpha values for uncorrected alpha values in all but the highest segment are determined by linear interpolation.

Abstract: A method renders a volume data set as an image in a volume rendering system. The volume data set includes a plurality of voxels stored in a memory. The volume rendering system includes a plurality of parallel processing pipelines. The image includes a plurality of pixels stored in an image buffer. A determination is made whether a particular voxel of the volume data set will contribute to the image. The voxel is read into one of the plurality of pipelines only if the particular voxel contributes to a particular pixel of the image.

Abstract: A volume rendering pipeline includes a plurality of processing stages such as a gradient estimation stage, an interpolation stage, a classification stage, an illumination stage, and a compositing stage. The stages are connected to each other by multiplexers. A first multiplexer connects an output of a first stage to an input of a second stage. A second multiplexer connects an output of the second stage to an input of the first stage. A third multiplexer has inputs connected to the output of the first stage and the output of the second stage, the first, second, and third multiplexers are responsive to a select signal to configure the stages of the rendering pipeline for processing the volume data set.

Abstract: A volume data set having voxels arranged according to an object coordinate system is shear-warp rendered by partitioning, relative to the object coordinate system, the volume data set into a plurality of axis aligned sets of voxels. The selected axis aligned sets of voxels are rendered as pixels in intermediate baseplanes. There is one intermediate baseplane for each selected set of axis aligned voxels. The intermediate baseplanes are combined and warped to an image.