Editing three-dimensional vertex data with undo facility

A three-dimensional configuration editing apparatus for interactive editing of a three-dimensional object displayed on a screen, comprising:

• instruction receiving means for receiving an instruction;
• shape information storing means for storing shape information in a plurality of data cells defining a present shape and restoration information needed to restore the present shape as it was immediately before most recent editing, said shape information storing means having
• a pointer for a list of one or more of the data cells which are newly created by the most recent editing,
• a pointer for a list of one or more of the data cells which have existed even before the most recent editing, and
• a pointer for a list of one or more of the data cells which are not necessary any more to define the present shape of the three-dimensional object because of the most recent editing, and each one of the data cells including
• a present value storing part for storing information regarding the present shape,
• a preceding value storing part for duplicating information currently stored in the present value storing part immediately before the most recent editing or undo processing and storing the restoration information therein, and
• a pointer for forming a list indicating linkage between the data cells;
• shape displaying means for displaying the present shape;
• editing means for editing the present shape stored in said shape information storing means in accordance with the instruction received by said instruction receiving means;
• undo preparing means for storing, during editing and undo processing, most recent editing in accordance with information stored in said shape information storing means.

A method of editing three-dimensional objects displayed on a computer screen in an interactive manner, comprising:

• storing positions of vertices of polygons arranged in three-dimensional space, each polygon having n sides and corresponding vertices connected by straight lines in at least one adjacent polygon;
• displaying a perspective view of the polygons to form a three-dimensional object;
• processing an editing instruction regarding at least one selected polygon forming the three-dimensional object to display a circumscribing rectangle of the at least one selected polygon and to enable interactive editing of the circumscribing rectangle;
• and
• updating said displaying of the polygons affected by the interactive editing of the at least one selected polygon.