Patent ID: 7015917

Claim:
A curved surface subdivision apparatus comprising: a subdivision level determination unit operable to determine the number of subdivisions for a curved surface; a work memory unit operable to hold control point information that defines a shape of the surface, as well as an intermediate result and a final result of a series of subdivision processing; a subdivision processing operation unit operable to read first control point information from the work memory unit, generate second control point information, and write the second control point information into the work memory unit, said first control point information being control point information about a sequence of control points that align in one of a first axis direction and a second axis direction of the surface before the subdivision processing, said second control point information being control point information about a sequence of control points which are newly generated as a result of the subdivision processing; and an operation control unit operable to determine first memory addresses and second memory addresses, said first memory addresses specifying an area of the work memory unit where the first control point information is stored, said second memory addresses specifying an area of the work memory unit where the second control point information is to be stored; wherein the subdivision processing operation unit writes, under control of the operation control unit, the second control point information into the area of the work memory unit specified by the second memory addresses, over the first control point information which is stored in the area of the work memory unit specified by the first memory addresses, said first memory addresses being a subset of said second memory addresses, and wherein the operation control unit compares the respective numbers of subdivisions in the first axis direction and the second axis direction of the surface, and controls an operation of the subdivision processing operation unit so that the last subdivision processing is executed in one of the first and second axis directions with a smaller number of subdivisions, and the immediately preceding subdivision processing is executed in the other one of the axis directions.