Feature-preserving based on Extended Marching Cube algorithm.   Carving, filling, and painting operations via 3D mouse or force feedback device, PHANToM.   Arbitrary graver shape imported from mesh.   Sharp features under low resolution of volume data. Our system applies Extended Marching Cube algorithm, which preserves sharp features. (Left) Result rendered by original Marching Cube algorithm. (Right) Result rendered by Extended Marching Cube algorithm. Our system provides arbitrary graver shapes imported from mesh..     Stereo display on a spherical display device, the Vision Station.   Realistic force simulation with force feedback device. Our system works with the PHANToM (a force feedback device) and the Vision Station (a spherical display device) running in stereo mode.   A fast interface to construct prototype of models for a 3D model retrieval system with more than 10,000 models from WWW.   Can modify existing 3D models imported from mesh data for post-processing.     K.-L. Perng, W.-T. Wang, M. Flanagan, and M. Ouhyoung. "A real-tme 3d virtual sculpting tool based on modified Marching Cubes". ICAT 2001.   L. P. Kobbelt, M. Botsch, U. Schwanecke, and H.-P. Seidel. "Feature-sensitive surface extraction from volume data". SIGGRAPH 2001.   T. Galyean and J. Hughe. "Sculpting: An interactive volumetric modeling techniques". SIGGRAPH 1991.