PURPOSE: To detect an adjacent state, etc., of each triangle with regard to an arbitray triangle group, and to generate a vertex train of high arithmetic processing efficiency, in the case of displaying the face of a solid, etc., by a triangular mesh, in a computer graphics.

CONSTITUTION: With regard to a triangle group to be plotted, a number is given to each triangle, and its adjacent relation is detected, respectively S1. Subsequently, by connecting the adjacent angles, a one-stroke writing-like Hamilton path is retrieved S4, and one piece of triangle train is determined. A vertex train following a vertex of each triangle is derives in order of this triangle train, and it becomes a triangular mesh.