Spring around torus 2

Author:
Thijs
It seems to me that the contraction of Yugemaku's string alternates from left to right. I've tried to imitate this, but I haven't quite succeeded. History: post - Juan Carlos' Spring Around Torus Setup: R = 7 r_{Torus} = 1 r_{Spring} = 2 A = 0.33 ω = 1 n = 12 t = Slider(0, 2 pi, 0.01, 1, 160, true, true, false, false) Tx(φ,θ) = (R + r_{Torus}*cos(θ)) * cos(φ) Ty(φ,θ) = (R + r_{Torus}*cos(θ)) * sin(φ) Tz(φ,θ) = r_{Torus} * sin(θ) Torus = Surface((Tx(φ,θ), Ty(φ,θ), Tz(φ,θ)), φ,0,2π, θ,0,2π) f(t) = (1 - A*cos(ω*t))^8 + 2 F = Integral(f) F2π(t) = F(t) * 2π/F(2π) Sx(φ) = (R + r_{Spring}*cos(n*φ)) * cos(F2π(φ+2t) - F2π(2t) + t) Sy(φ) = (R + r_{Spring}*cos(n*φ)) * sin(F2π(φ+2t) - F2π(2t) + t) Sz(φ) = r_{Spring}*sin(n*φ) Spring= Curve((Sx(φ), Sy(φ), Sz(φ)), φ,0,2π)