1. An apparatus for processing three-dimensional graphic images, said apparatus comprising: a first input part inputting a first two-dimensional graphic image; a second input part inputting a second two-dimensional graphic image; and a three-dimensional graphic image generating part generating a three-dimensional graphic image based on the first two-dimensional graphic image and the second two-dimensional graphic image, wherein the first two-dimensional graphic image is determined as a plan shape and the second two-dimensional graphic image is determined as a cross-sectional shape.