8-03 Construct the torus using the command "plot3d"

> restart;

> r:=3+cos(t):

> x:=r*cos(s):

> y:=r*sin(s):

> z:=sin(t):

> a:=plot3d([x,y,z],t=0..2*Pi,s=0..2*Pi,scaling=constrained,grid=[30,50]):

> a;

> with(plottools);

> vrml(a,"c:/8-03.wrl",background_color=white);

>