Abstract:

For some data sources, a voxel-based representation can provide much more informative data visualization than the surface-based representation of conventional computer graphics. For example, the image data from a 3D Magnetic Resonance Image (MRI) scan consists of a wealth of information about internal structure, function, and anatomy. Using volume rendering with appropriate preprocessing, all of this information can be effectively presented to the attending physician or radiologist. In contrast, surface models derived from the MRI data discard internal structure, cannot be used to represent objects with poorly defined edges or surfaces, and are sensitive to segmentation errors. In this paper, we propose the use of a voxel-based data representation not only for visualization, but also for modeling objects and structures derived from volumetric data. The paper describes work in progress towards demonstrating the utility of a voxel-based format for modeling physical interactions between virtual objects. Data structures are presented that help to optimize storage requirements and preserve object integrity during object movement. An adaptation to volume rendering algorithms is discussed that enables objects to be rendered individually and then combined in a final compositing step. Finally, algorithms and prototype systems are presented that use a voxel-based format to model physical interactions between objects. These physical interactions include collision detection and avoidance of object interpenetration, haptic, or tactile, exploration of virtual objects using a force feedback device, and object deformation.