Formula Spring

Some Helixes are just to hard to make with the helix-spline.
Here is a formula-spline to make a helix that is more compact at the ends.

Formula Spring

Follow up:

The formula has 3 components to define the shape followed by two to define the upper and lower limit (Tmin and Tmax) and the samples.
X(t)=100 * sin(t * pi)
Y(t)=300 * tanh(0.08 * t)
Z(t)=100 * cos(t * pi)
Tmin=-17
Tmax=17
Samples=300 or more

In the X and Z the 100 defines the diameter.
In the Y the 300 defines the hight and the 0.08 defines how compact the ends are.

Many more formulas on the fantastic site of Jürgen Meier

Enjoy! And please post your comments or suggestions for new tutorials.
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2005-08-23 — Formula — 3 feedbacks » —

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3 comments

Comment from: dhumbert [Visitor] : 2005-09-07 @ 10:18

Bonjour,
très bonne initiative : enfin, on peut comprimer les bouts du ressort. Ce type de proposition est très pédagogique : on regarde, on essaie et on s'approprie.
merci pour tous ceux qui n'ont plus qu'un lointain souvenir des cours de maths.DH

Comment from: Prografx [Visitor] : 2006-04-15 @ 23:51

I'm not sure if this "Leave a comment" section is for comments only, or can include
questions. But here's goes:
I have looked at all the examples here, and on the Jürgen Meier site, but have not
been able to find a formula that unwinds the helix. Specifically, what I'm tryng to
do is unwind a helix in specific places. For example, a full twist on both ends, but
unwound in the middle. This will be used in a animation for a DNA strand.

Thanks.

Comment from: Itsmil [Visitor] : 2009-01-10 @ 13:59