Closest Point On A Curve

[klingon]

I have 3D curve and an external point.
I need to determine the (X,Y,Z) of the point on the 3Dcurve that is the nearest to my extarnal point.
Is there a way to obtain that ?

Many thanks
Marco

[imasters]

Hi Marco,

The maya devkit comes with the source for an example plugin called closestPointOnCurve. If you compile this up it will give you a command and a dg node that do exactly what you want.

Cheers,

Ian.

[klingon]

Thanks for fast reply.
What do I need to compile? I don't have VisualStudio.

Marco

(I'm on Maya7 - Win2000)

[imasters]

Difficult for me to help you there because I'm linux based and it's a long while since I did any plugin dev on windows. However, there are 2 options.

www.gooroos.com do their own free version of the closest point on curve plugin that you can download.

A quick search on the highend API forum revealed this tutorial on compiling maya plugins on windows without vc http://forums.cgsociety.org/showthread.php?t=227419

Beyond that I can only suggest browsing the highend maya API forum, there looks to be plenty of advice on compiling without visual studio.

Hope you get it going.

Ian.

[joojaa]

One does not need to compile this node. because it comes with the bonus tools package precompiled in older mayas.

And maya 7 has this node already built in, no need to compile. Infact the devikit example is slower than the incore version.

[klingon]

And maya 7 has this node already built in, no need to compile

How can I create/use this ClosestPointOnCurve node?
In doc I've found a closestPointOnSurface node but nothing similar for curves.

Marco

[imasters]

Load the plugin closestPointOnCurve.mll in the plugin manager.

Create a closestPointOnCurve node:

CODE
closestPointOnCurve -name cpocNode -inPosition 1 2 3 yourCurveNode;

This will return the name of the new closestPointOnCurveNode. You should also be able to set your input point in the node's attrbibute editor.

You can then use the command in query mode to get info from the node:

CODE
closestPointOnCurve -q -position cpocNode;

Will return the closest point on the curve.

You can also use these other query flags.

-normal
-tangent
-paramU
-distance

Ian

[joojaa]

Ahh yes i misread (didnt notice the manual comment that its not part of main install, i use the manual as a scarpbook for my comments too so i allways add all new nodes there so when i do search i se no difference). But yes you can use closest point of surface for same effect...

All you do is make a curve duplicate it loft between the curves and use closest point on that surface. its a bit ureliable whan they are absolutely top of eachother so move the other curve someway by 0.0001 or something. this would still yeld you with acceptabble precicion for most jobs.

but yes download the bonus tools package its compiled ready there along with uber usefull closest point on mesh node. go to www.alias.com.

[klingon]

Wonderfull!!
Just downloaded the BonusTools from www.alias.com.
It works great, clean and straight to my need.

Thanx a lot again
Marco