Abstract: A system is disclosed for subdividing parametric patches for use in a computer graphics system to develop images. The system utilizes initial data, provided as by an interactive user, to represent control points for an initial patch from which the system rapidly computes control points for subpatches using parallel processors. The disclosed system is recursive so that each level of subdivision leads to greater refinement of an initial patch. In one embodiment, the processors in the system compute multiple control points, the grouping of processors exploiting patch symmetrical properties.

Abstract: This disclosure relates to a system and method for realizing asynchronous sequential circuits in a manner analagous to the stored state method for synchronous sequential circuits. The circuit is a stored state circuit including a memory and an output register with an input line and an input request line coupled to the memory and the output register having an output data line and an output acknowledge line. A pulse generator is coupled to the input request line so as to generate a timing signal, for transmission to the output register, a fixed period of time after receipt of a request signal on the input request line. A request signal will not appear on the input request line until a data signal on the input data line has stabilized. Furthermore, an acknowledge signal will not be generated until a signal on the output data line has stabilized.