(1). Field of the Invention
This invention generally relates to providing a method for graphically selecting a sub-volume (a subset of the original volume) within a larger volume containing three-dimensional data. The tool uses state of the art graphical user interface (GUI) technology for manipulating the selected sub-volume. The processing might include but is not limited to route planning, managing mine placement, target search planning, off-board sensor management, counter detection avoidance management, oceanographic/atmospheric surveillance and weapon trajectory planning. In addition, this software engineering tool would be a useful addition to any computer aided design (CAD) program. In particular, it is a method and device for detecting coordinates of and computing a volume of a selected and/or manipulated sub-volume.
(2). Description of the Prior Art
Earlier methods for selecting a sub-volume include the computation of the sub-volume corner coordinates and the editing of the data in a tabular or spread sheet format. This can be a time consuming method which introduces errors. Another alternative is the virtual reality technique of walking or flying through the data to a point which gives an equivalent view to the inventive method. This alternative, however, does not permit an accurate and systematic sub-volume by sub-volume search capability.
The following patents, for example, disclose some selection and manipulation of a sub-volume: U.S. Pat. No. 4,766,556 to Arakawa; U.S. Pat. No. 4,812,829 to Ebina et al.; U.S. Pat. No. 5,067,167 to Berger; U.S. Pat. No. 5,414,801 to Smith et al.; U.S. Pat. No. 5,432,984 to Funaki; and U.S. Pat. No. 5,471,569 to Katoh. However, none of these patents disclose a method for selecting a sub-volume using a mouse.
Specifically, the patent to Smith et al. presents a method for viewing elements of a three-dimensional space by changing the viewpoint and viewing angle using a mouse and function keys. This is often called the "fly through method." This approach is exactly the approach the present invention replaces with a more efficient, more precisely controlled, and more user friendly method. The inventive approach selects the sub-volume directly, thereby avoiding the necessity of picking the viewpoint and viewing angle. The inventive method of selecting the sub-volume boundaries is completely new and not included in the Smith et al. patent. Further, the clipping operation described in Smith et al. is two-dimensional whereas the present technique is three-dimensional.
The patent to Berger discloses a method for rotating three-dimensional images and does not provide a method for selecting three-dimensional sub-volumes. Instead, Berger permits the selection of different viewpoints via rotation.
Regarding each of the patents to Ebina et al., Katoh, Funaki, and Arakawa, there are disclosed various techniques for pointing to and selecting objects in a three-dimensional space, and do not permit the selection of a sub-volume of three-dimensional space. Further, the present inventive method of using the mouse for selecting the sub-volume is not described in, any of the above patents.
It should be understood that the present invention would in fact enhance the functionality of the above patents. The described and claimed technique of sub-volume selection would serve as an additional component involved in the process of three-dimensional object selection. It would be used prior the selection of the objects and would make the operation simpler and more efficient.