Sin[t]
takes values between -1
and 1
. If you want a whole circle you can multiply by Pi
:
With[{r = 1},
torus[{u_, v_}] := {(3 + Cos[u]) Cos[v], (3 + Cos[u]) Sin[v],
r Sin[u]}];
Show[ParametricPlot3D[torus[{u, v}], {u, 0, 2 \[Pi]}, {v, 0, 2 \[Pi]},
Mesh -> None],
ParametricPlot3D[torus[{Pi*Sin[t], 0}], {t, 0, 2 \[Pi]}],
Graphics3D[{Arrowheads[0.05],
Arrow[Tube@{torus[{Sin[2 \[Pi]*.49], 0}],
torus[{Sin[2 \[Pi]*.51], 0}]}]}]]
or else replace Sin[t]
with simply t
:
With[{r = 1},
torus[{u_, v_}] := {(3 + Cos[u]) Cos[v], (3 + Cos[u]) Sin[v],
r Sin[u]}];
Show[ParametricPlot3D[torus[{u, v}], {u, 0, 2 \[Pi]}, {v, 0, 2 \[Pi]},
Mesh -> None],
ParametricPlot3D[torus[{t, 0}], {t, 0, 2 \[Pi]}, PlotStyle -> Black],
Graphics3D[{Black, Arrowheads[0.05],
Arrow[Tube@{torus[{Sin[2 \[Pi]*.45], 0}],
torus[{Sin[2 \[Pi]*.51], 0}]}]}]]