Abstract: A device for generating parallel and perspective projections of 3-D voxel-based images, viewed along arbitrary viewing directions. The method involves using retrieval parameters to retrieve voxels of the 3-D voxel-based image from discrete 3-D voxel space. Then, the 3-D voxel-based image is viewed along an arbitrary viewing direction specified by viewing parameters in a manner independent of the retrieval parameters. Apparatus is also provided using a 3-D voxel-based image viewed along an arbitrary viewing direction specified by viewing parameters in a manner independent of the retrieval parameters. Apparatus is also provided utilizing a 3-D memory storage device organized in accordance with a 3-D skewed memory storage scheme, and providing for conflict-free retrieval of voxel-based retrieval rays along a retrieval direction of the memory storage device.