SetDirectory["C:\\drorbn\\AcademicPensieve\\2012-04"]

s1[t_] := 1+0.5(1-t)(1+t); s2[t_] := 1-0.25(1-t)(1+t);
tilt[t_] := 0*0.5(1-t)(1+t);
p1[t_] := {1.25t, 0, -0.3Sin[π t]}; p2[t_] := -p1[t];
Ring[p_, s_, tilt_] := Tube[
Table[
p+s{Cos[θ]Cos[tilt], Sin[θ], Cos[θ]Sin[tilt]},
{θ, 0, 2π, 2π/72}
], 0.24s
];
Rings[t_] := Graphics3D[{
Red, Ring[p1[t], s1[t], tilt[t]],
Blue, Ring[p2[t], s2[t], tilt[t]]
},
ViewPoint -> {0,-3,1.5}, Boxed -> False, ImageSize -> 480
];
Export[
"FlyingRings.png",
Table[
Rasterize[Rings[t], RasterSize -> 480],
{t, -1,1,1/3}
] // GraphicsColumn
]