Abstract
This paper proposes the method of inputting a planar log-aesthetic curve with compound-rhythm by use of four control points. The log-aesthetic curve does not exhibit any undulations of curvature since its curvature monotonically increases or decreases and it is suitable to be used for practical product design. The input methods by use of control points presented so far can generate only one log-aesthetic curve and it is not capable enough to represent characteristic lines of industrial products. We show that the compound-rhythm log-aesthetic curve made up of two log-aesthetic curve segments connected with G^3 continuity has an enough expression ability to represent character lines of cars by illustrating practical design examples.
