A morphology model using shape-transformation rules defined for inner states of parts

This paper presents a method to describe the complicated shapes of artificial creatures and simulate their growth. In this method each virtual creature is assumed to be composed of several primitive parts such as spheres, cylinders, and its growth from a single part is described. At any step of the growth of the virtual creature, each part has its own "current inner state" which is changed repeatedly by pre-defined transformation rules. The transformation rules are classified into three categories: division, stretch and growth. By applying these transformation rules to the initial single part repeatedly, complicated shapes like animals are generated. In this paper, the basic scheme of the proposed method is described and several generated shapes are demonstrated.