OrientToSurface, OrientToCurve Direction

Hello All,

I want to Copy a bunch of objects to a surface (elipse) and I want them to point to the middle.
As you van see they are oriented perpendicular to the curve (in this example I am using curves, I guess the same principles apply), but I need the to point to the center of the elipse.
How can this be done?

Many thanks, Robert

Use the command _Flow and/or FlowAlongSrf.

You can use the command _ArrayCrv too but you’ll have to draw a base curve the same length as the ellipse you’d like it to be copied along.


Many thanks Andy,

Wow so many commands/options in Rhino, very impressive.
Probably in this case its not going to do me good.
I need to copy several instances of Prongs with irregular intervals to a surface like in the picture.
Any other idea?

Kind regards, Robert

Maybe use ArrayCrv

select your object.
Select your curve
Say how many items.

Or do they need to be aimed at the exact center?

Hi Robert - Orient, Copy=Yes, Scale=No, I think, is what you are after. Snap the target points to the curve (Near or Point OSnap if you have your irregular locations marked) and to the center of the ellipse.


Many Thanks gentlemen for helping :slight_smile:

I did a screencapture of what I’m after, I am following a tutorial on Digital Tutors and this is the way the instructor is doing it.

But as you can see the prongs don’t orient in the right way, I actually just realized that they should not point to the center of the ellipse, but perpendicular to the path that they are snapping to.

Many thanks, Robert

Hi Robert- he’s using OrientOnSrf - the object is oriented so that the original’s Cplane Z direction is mapped the the surface normal. For rotation, the vector between the two reference points is mapped to the target surface U direction if no rotation is specified.


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Thanks Pascal,

The video is not from the DT instructor but its me trying to make it work.
As you can see they are not alligned correctly.

Kind regards, Robert

Yeah, you may need to set Rotation to Prompt and snap to a point in the center of your ellipse. Start with the prongs aligned to X or Y and set your reference point at the mid between the centers and along X or Y as looks best. That direction will determine how the default rotation is on the surface - it will align to U on the target surface. If your surface’s UV is ‘around’ then I’d think either U or V will align ‘radially’ . Post your file if you like, I’ll take a look.


Many thanks Pascal, I included the file at the bottom, and will have another play with your suggestions.
I also have two other issues if you don’t mind :wink:

In the image below you can see some weird shading artifacts, it seems as if the edges are off or overlapping, but I cannot find anything like that?

And then I have a problem with this surface, for what I remember it was quite alright in the beginning but something as happened to it along the way. Any suggestion on a way of fixing?

Again many thanks for helping, its very much appreciated.
Regards, Robert

Ring_01 014.3dm (7.4 MB)

Hi Robert - plain old Orient will work fine here since the target surface is planar. Here’s what I’d do:

  1. Get the two curves that define that top surface on screen and the prongs, hide everything else.
  2. Use CrvSeam to line up the seams of the curves to a Quad (Osnap)
  3. TweenCurves to create a mid curve between the two, unless you have one already someplace.
  4. Use AreaCentroid to mark the center of the curve.
  5. Orient with Copy=Yes and Scale=No, Set the target points on that mid curve and the center point from step 4.

Does that do what you want?
The tweaky surfaces are a differnet matter… I’ll see if I cn back track and suggest a different process.

Thanks Pascal :slight_smile:

Well it did more or less what I wanted in my initial post, except that the surface is not planar.

But as i mentioned in the post with the screencapture, they will need to be perpendicular to the ellipse like the green ones.

I will investigate this further of course; maybe I could draw guide from the ellipse perpendicular to it and oriented to the plane.

Of Course for other suggestions I am all open :slight_smile:

Regards, Robert

I see … I assumed the file you posted had the surfaces you are working with. If it is not a planar surface, OrientOnSrf and set Rotation to Prompt - snap the rotation to a center marker.