Internal structures, features and properties in volumetric datasets are mostly obscured and hidden. In order to reveal and explore them, appropriate tools are required to remove and carve the occluding materials, isolate and extract different regions of interest. A framework of interactive tools are provided for real-time volume manipulation, sculpting, segmentation, and visualization. A GPU-based point radiation technique provides as a fundamental building block to create a collection of high-quality volume manipulation tools for direct drilling, lasering, peeling, cutting, and/or pasting. Interactive parallel region growing segmentation is described that allows multiple seeds planting by direct sketching on different volumetric regions with segmentation results dynamically modified during the process. The point radiation technique creates high-quality real-time feedback of the segmented regions during the seeded growing …