Chris Colefax wrote:
>To avoid confusion I think it helps to use the word 'tangent' when you're
>talking about a vector tangential to the curve

Tangent, yes that's the word. I couldn't remember it.

>Now, given the example you posted to .binaries and your description of your
>goal I would say the method you're using (inverse kinematics) is quite
>suitable.

I'll use Mike Williams' + Peter Popov's methods, but now with your
suggestion I'll give my original idea another try as well. I'll then see
which works best.

>To avoid kinking perhaps you could apply an extra constraint to
>each link which checks the angle it forms with the links around it, eg.
>given three sphere centres (P1, P2, and P3) you could calculate the cosine
>of the angle using:
>
>   vdot (vnormalize (P2 - P1), vnormalize (P3 - P2))
>
>To stop the kinking you want this to be as close as possible to -1 (the
>cosine of 180 degrees), so in addition to being pulled by the endpoints and
>tangents and being forced to be separated by a certain distance, the
spheres
>also try to form a straight line (or as close as possible given the other
>constraints).

I understand you so far, i.e. how to find out how much the curve is bended
on a given point.
However, to me the problem is how to straighten out the curve. I mean, I can
see that I want to get the cosine of the angle as close as possible to -1,
but it is how to accomplish this that is the problem.

Has you any ideas as to how to accomplish it?

Greetings,

Rune

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