Script For Middle/average Between 2 Curves

[jenn7]

hi guys,
bit rusty with MEL..

I have 2 curves each with their own path/direction, they are offset by an amount so there is a clear space between them.

I need a third curve to be created that is exactly in the middle of the 2 curves which are existing.

Any ideas?

thanks
J

[ewerybody]

Do you always have equal amounts of CVs on the curves?
Then I'd say copy one of the curves, browse the CVs, create an average value for each pair and assign it to the according new CVs.

This would be most exact. If you have different numbers of CVs you can loop through the curvePoints by a discrete amount of times but creating CVs on the average would not result in an exact curve... Would creating EPs work on a curvePoint avarage? Probably more.. but EPs are bitchy..

[jenn7]

thanks for your response.

no different amount of CVs per curve, but yes I didnt think of this method.

When you say loop through curve points what do you mean exactly, Im not following?

cheers
J

[ewerybody]

If you have 10 CVs on a Nurbs curve you can query any number of curvePoints via float in the range of 0-10 giving you the exact position of a point on the curve.
So if you have 2 curves, one with 11 and another with 18 CVs you could query 5.5 and 9 to get the positions for an average point at 50%...
So you would have to decide how many times you want to sample the curvePoints.

But don't bother you don't have the problem if you have the same number of CVs.

[joojaa]

QUOTE
no different amount of CVs per curve, but yes I didnt think of this method.

Then you can just loft and take the middle parameter and copy it to curve and hide surface. This has a advantage that you can now use history if you change originals the middle one follows, and you an easily do 2/3 from this curve to that curve things too.

[jenn7]

thanks guys it seems a bit more manual than i had hoped, was hoping a neat little script could do it. I try what you have suggested..

J

[joojaa]

QUOTE(jenn7 @ 05/13/09, 03:50 PM) [snapback]307690[/snapback]
thanks guys it seems a bit more manual than i had hoped, was hoping a neat little script could do it.

Aumm... Since you didnt ask for code it is assumed you ask for a procedure. Manual is the same thing as script. If you dont know how to do it manually you dont know how to script it. Thus telling how to do it manually is equal to telling how to script it.

Mel can not as a rule do anything, asside fro very fringe developper tools*, you can not do manually. So yes this is a prcedure you put into a script if you so wish.

*even so one should refrain from treating maya as a database even when one can do so. There's a clean division of labour in maya

[ewerybody]

QUOTE
Any ideas?
.. in the mel forum sounded like you want an idea how to do it ;]

scripting such a thing is a matter of some minutes if you are familar with loops and arrays.
don't wanna give it a try?

[jenn7]

thanks guys, its just im a bit rusty with code, need to jump back in. Yes, and im always analyising what manual procedures im doing with regard to MEL.

thanks!

[joojaa]

CODE
{
  $selected=ls -sl -dag -type nurbsCurve -tl 2;
  $loft=loft -autoReverse 1 -ch 1 -u 1 -c 0 -ar 1 -d 3 -ss 1
              -rn 0 -po 0 -rsn true $selected[0] $selected[1];
  duplicateCurve -ch 1 -rn 0 -local 0  ($loft[0]+".v[0.5]");
  setAttr ($loft[0]+".intermediateObject") 1;
}

[ewerybody]

Wow sweet! Works even like a charm with much different numbers of CVs