METHOD AND DEVICE FOR EXPRESSING GRAPHIC PRIMITIVE AND COMPUTER SYSTEM

摘要

PURPOSE: To obtain a device and method for suitably and speedily performing a patch level test. ;CONSTITUTION: At first, the perpendicular line function of a patch is calculated by using the control point of a polygonal or Bezier-shaped rational patch. The vector of the perpendicular line function is used for constituting floating conical by using the projecting outer-shell characteristic. The floating conical is converted within space and cut by two parallel flat faces perpendicular to the axis lines of the conical. A volume facing a front side and a volume facing a rear side are constituted from this information. Then the volumes are used for obtaining information concerning the patch capable of improving the processing speed of the patch. Operation taking time for calculating the perpendicular line function and the floating conical is implemented in constituting the patch. Consequently whether the patch faces the front or rear side is judged through the use of the same conical of a perpendicular line with respect to views after the same patch, to sufficiently reduce processing time.;COPYRIGHT: (C)1994,JPO