| 摘要 |
PURPOSE:To speed up the retrieving speed of the title system by correctly calculating intersections of primitives and a gaze vector by accessing the minimum number of primitives even when the number of the primitives is large when three-dimensional data are calculated as intersections. CONSTITUTION:A world coordinate system is previously divided into plural rectangular parallelopiped bodies and a 1st table indicating the connecting relations between each rectangular parallelopiped body W' and a 2nd table indicating the relation between each rectangular parallelopiped body and the primitives contained in the body by defining the primitives by using relative addresses from a reference point P0 of each body are prepared. At the time of calculating intersections of the glance vector and primitives, another rectangular parallelopiped body connected to the currently noticed body is specified by referring to the 2nd table when the currently noticed body is retrieved and to the 1st table when the body to be retrieved next is retrieved. Therefore, the retrieving speed is improved. |
