walec=ParametricPlot3D[{ 1/2 (1+Cos[u]), 1/2 Sin[u],z},{u,0,2\[Pi]},{z,-1,1},Boxed->False,Axes->False,ColorFunction->ColorData["SolarColors"],(* PlotStyle->None, *)Mesh->{21,20}]; sfera=ParametricPlot3D[{Sin[\[CurlyTheta]]Cos[\[CurlyPhi]],Sin[\[CurlyTheta]]Sin[\[CurlyPhi]],Cos[\[CurlyTheta]]},{\[CurlyTheta],0,\[Pi]},{\[CurlyPhi],0,2\[Pi]},Boxed->False,Axes->False,PlotStyle->None,Mesh->{21,20}]; krzywaVivianiego=ParametricPlot3D[{a(1+Cos[t]),a Sin[t],2a Sin[t/2]}/.a->1/2,{t,-2\[Pi],2\[Pi]},PlotStyle->{Blue,Thick}];