A direct 3-D shape modeling system

A newly developed 3-D shape modeling system based on constructive solid geometry (CSG) is described, in which a direct and interactive shape modeling process is supported. This feature is realized by a voxel model for real-time set operations, and a volume scanning display for the direct visualization of the voxel model, besides the CSG model for data structure management. The set operations on the voxel model can be executed as simple bit calculations, and therefore, the voxel data for the set object can be created in real time. The volume scanning display is a suitable device for presenting the voxel data. There is not need for intensive calculations to display the set objects. The volume scanning display can provide exact 3-D images without goggles or glasses. The concept should be useful in an actual modeling environment