実は一本のリングなのだ。 c=1.0 x(u_,v_) = cos(u_)* (c + sin(v_)* cos(u_) - sin(2* v_)* sin(u_) / 2) y(u_,v_) = sin(u_) *(c + sin(v_)* cos(u_) - sin(2* v_) *sin(u_) / 2) z(u_,v_) = sin(u_) *sin(v_) + cos(u_)* sin(2* v_) / 2 -π≦u_≦π、-π≦v_≦π…