mjhjmtu

This question follows from the example below

Mapping StreamPlot onto spherical surfaces

When I'm trying to remove the arrows I cannot get the 3d graphics:

sp = StreamPlot[Cot[θ] Cos[ϕ], -Sin[ϕ], ϕ, -π, π, θ, 0, π, 
 StreamColorFunction -> Hue, 
 StreamScale -> None, ImageSize -> 200];

sp3d = Graphics3D[
 sp[[1]] /. 
 Arrow[z_] :> 
 Arrow[z /. x_Real, y_Real :> Cos[x] Sin[y], Sin[y] Sin[x], 
 Cos[y]], ImageSize -> 200];
Row[sp, sp3d, Spacer[5]]

The result is below. Any idea how to get the 3d graphics without the arrows?

You can also post-process the graphics objects sp and sp3d from the accepted answer in the the linked q/a (1) to change Arrows to Lines or (2) to change the Arrowheads directive to Arrowheads[0]:

sp = StreamPlot[Cot[θ] Cos[ϕ], -Sin[ϕ], ϕ, - π, π, θ, 0, π, 
 StreamColorFunction -> Hue, ImageSize -> 200];
sp3d = Graphics3D[sp[[1]] /. Arrow[z_] :> 
 Arrow[z /. x_Real, y_Real :> Cos[x] Sin[y], Sin[y] Sin[x], Cos[y]], 
 ImageSize -> 200];

Row[sp, sp3d /. Arrow -> Line, Spacer[5]]

Row[sp, sp3d /. Arrowheads[_] :> Arrowheads[0], Spacer[5]]

same picture

The sp output includes a GraphicsComplex, so the arguments of the primitives are indices into the GraphicsComplex and not coordinates. Also, your StreamPlot uses Line primitives instead of Arrow primitives. So, a corrected version would be:

Graphics3D[
 ReplaceAll[
 Normal[sp][[1]],
 Line[z_]:>Line[z/.x_Real,y_Real:>Cos[x] Sin[y],Sin[y] Sin[x],Cos[y]]
 ]
]

Note that Normal modifies the colors, so an alternative is to transform the GraphicsComplex:

Graphics3D[
 ReplaceAll[
 sp[[1]],
 x_Real,y_Real:>Cos[x] Sin[y],Sin[y] Sin[x],Cos[y]
 ],
 ImageSize->400
]

The latter method is identical to @Jason's now deleted answer.