Computer readable program product, method of image processing and image processing system

A computer readable program product for storing a game program making the computer:

• draw a game character comprised of a plurality of polygons including non-planar quadrilateral polygons designated as either concave or convex,
• judge whether a non-planar quadrilateral polygon, divided into two triangular planes with a straight line connecting a pair of facing vertexes forming a ridge line, is formed in a concave or convex shape about the ridge line when changing and drawing the form of the game character in response to an input operation of a player,
• change the ridge line to a straight line connecting the other pair of facing vertexes of the non-planar quadrilateral polygon when it is judged that the non-planar quadrilateral polygon,is not formed in a designated shape,
• divide the non-planar quadrilateral polygon by the changed straight line to generate two independent triangular polygons, and
• draw the game character based on polygons comprising the generated triangular polygons.

A method of image processing comprising:

• drawing a game character comprising a plurality of polygons including non-planar quadrilateral polygons designated as either concave or convex,
• judging whether a non-planar quadrilateral polygon, divided into two triangular planes with a straight line connecting a pair of facing vertexes forming a ridge line, is formed in a concave or convex shape about the ridge line when changing and drawing the form of the game character in response to an input operation of a player,
• changing the ridge line to a straight line connecting the other pair of facing vertexes of the non-planar quadrilateral polygon when it is judged that the non-planar quadrilateral polygon is not formed in a designated shape,
• dividing the non-planar quadrilateral polygon by the changed straight line to generate two independent triangular polygons, and
• drawing the game character based on polygons comprising the generated triangular polygons.

An apparatus comprising a computer for controlling a program and a program product storing a program for making the computer control the game, wherein said program makes the computer:

• draw a game character comprised of a plurality of polygons including non-planar quadrilateral polygons designated as either concave or convex,
• judge whether a non-planar quadrilateral polygon, divided into two triangular planes with a straight line connecting the pair of facing vertexes forming a ridge line, is formed in a concave or convex shape about the ridge line when changing and drawing the form of the game character in response to an input operation of a player,
• change the ridge line to a straight line connecting the other pair of facing vertexes of the non-planar quadrilateral polygon when it is judged that the non-planar quadrilateral polygon is not formed in a designated shape,
• divide the quadrilateral polygon by the changed straight line to generate two independent triangular polygons, and
• draw the game character based on polygons comprising the generated polygons.