# Tubes on spiral - Graphics 3D

Now I am working on something like this:

helix[a_, b_][t_] := {a*Cos[t], a*Sin[t], b*t}
listept1 = Table[helix[1, 0.35][t], {t, 0, 4 Pi, .25}];
listept2 = Table[helix[0.25, 0.35][t], {t, 0, 4 Pi, .25}];
mapdecalgarde = Map[{0, 0, 0.5} + # &, {listept1}, {2}];
exterieurSup1 = Map[{0, 0, 0.1} + # &, listept1];
mapdecalgarde1 = Map[{0, 0, 0.5} + # &, listept1];
Listedepointgardecorps1 =
Flatten[{{mapdecalgarde1}, {exterieurSup1}}, 1];
ptsGarCor1 = Transpose[Listedepointgardecorps1];
ligneGardeCor1 = Map[Line, ptsGarCor1];
barriere = Graphics3D[{Opacity[0.25], RGBColor[1, 3, 0], Tube[ptsGarCor1]}]


and simple rods I want to substitute with this particular shape:

Graphics3D[{CapForm["Round"], Tube[{{0, 100, 0}, {100, 300, 0}, {300, 300, 100}}, 40]},  Boxed -> False, PlotRange -> All]


in this orientation:

so it freely rotates around (let say) Z direction where XY plane alongside the twofold symmetry axis.

• What is your question exactly? – march Sep 23 '15 at 22:48
• How to substitute ordinary rods with bent-core rods (on spiral)? – ATomek Sep 23 '15 at 23:15
• Your helix[ ] lacks the definition – Dr. belisarius Sep 23 '15 at 23:50
• I have edited the code and added definition of helix[] (which I have previously forgot to include). – ATomek Sep 23 '15 at 23:58
• Like this? – Michael E2 Sep 24 '15 at 0:03

Are you wanting the kinks to point directly away from the z-axis? If not I'll remove this answer.

carat[{{x_, y_, z1_}, {x_, y_, z2_}}] :=
Translate[
Rotate[Translate[
Tube[{{x, y, z1}, {x + (z2 - z1)/4 Sqrt[3/7], y, (z1 + z2)/2}, {x, y, z2}},
(z2 - z1)/10], {-x, -y, 0}], π + ArcTan[x, y], {0, 0, 1}], {x, y, 0}]

Graphics3D[{CapForm["Round"], Opacity[0.25], RGBColor[1, 3, 0],
carat /@ ptsGarCor1}, Boxed -> False]


• I want to recreate something like this Link – ATomek Sep 24 '15 at 10:02
• @ATomek as far as I can tell, that's what I think my solution does. – Chip Hurst Sep 24 '15 at 15:44