(* this is an animation sequence of a torus whose radius increases
until it becomes a sphere. it first generates the frames, then animates
them *)

(* load additional packages required *)
<</usr/local/math/Packages/Graphics/ParametricPlot3D.m
<</usr/local/math/Packages/Graphics/Animation.m

(* create and animate frames *)
Animate[
a = i ;
b = 1 - i ;

p1 = ParametricPlot3D[{(b + a Cos[alpha]) Cos[theta], (b + a Cos[alpha]) Sin[theta], a Sin[alpha]}, {theta,0,2 Pi}, {alpha, 0, 2 Pi}] ;

Show[ Graphics3D[ {EdgeForm[ ], p1[[1]]} ], Boxed -> False] ,
{i, .1, .9, .05}]