adds two small wrinkles 414 and 420 adjacent to wrinkles 412 and 413 respectively by producing two sets of polygons p 22 and p 23 and p 24 and p 25 respectively fig2 through fig3 e illustrate the method of determining the muscle movement of upper arm ua fig2 illustrates the content of area 308 of ram 206 fig2 area 308 stores the muscle movement generating software which administers the muscle movement of upper arm ua as described in details hereinafter fig2 illustrates the concept of the present invention as described in fig2 arm ar of an object human being is composed of hand hd lower arm la joint jt and upper arm ua when arm ar is bent muscle m bulges and thereby increases the thickness of upper arm ua fig2 illustrates the method of generating the muscle movement the most convenient way to generate the muscle movement is to have the muscle m composed with a plurality of polygons in the example described in fig2 muscle m is composed of polygons p 42 p 43 p 44 and p 45 polygons p 46 and p 47 are part of upper arm ua but not part of muscle m as illustrated in fig2 ram 206 fig2 includes area 309 area 309 stores a plurality of data which are necessary to produce the muscle movement of upper arm ua fig2 illustrates the content of area 309 fig2 of ram 206 area 309 includes two types of data i e the data representing the angle of joint jt fig2 produced.