FlowAlongSrf on right spot


I’m trying to project a srf on another srf and try to have it on the same spot as when I do it with a crv.
Hope the following the pictures say more than my words :).

On the first picture you can see a dupborder and projected it on the top surface. I would like to project the bottom surface on it on the same spot. The second is a topview where the underlaying surface should “land”.

Is it possible to project it? I tried flowalongsrf but it will be stretched or on the wrong place.

Anyone an idea?

Well, to get a “projected” surface as you want, I think the workaround is to project the surface border to the other surface (as you did with the curve above) then use the curves to trim/split a copy of the surface projected to… This could probably be automated (at least partially). That would give you the correct shaped projected surface - but, its underlying structure would not be same as the original surface you wanted to project.

Other than that, AFAIK it’s not currently possible to project surfaces onto other surfaces in Rhino (yet).


What I do is meshoutline the top srf then planarsrf the curve and flowalongsrf but it get stretched etc and when I trim it it doesn’t flow alongside the surface.

What you mean with project a copy on the surface?

Don’t know if the attached example helps explain?


ProjSrfExample.3dm(539.8 KB)

step 1 and 2 works but how do you copy the srf on the place of the trimmed opening?

maybe my question was wrong but now you create holes on the projected places but I want to move the surface itself on the other projected surface :slight_smile:

Oke I’m getting close now :stuck_out_tongue: I projected the meshoutline of the to projected srf.
Split the top object.
Dupborder the to projected srf and planarsrf
Then flowalongsrf. Almost perfect :slight_smile: but getting close :slight_smile:

Hi Jordy,

It sounds like you could use Pascal’s ProjectObject script.


IMO, ProjectObject is by far the most useful deformation tool in Rhino.


@jim Exactly what I need. Works excellent.
@Helvetosaur Thank you for your help.

Hi Jordy, You dont need Scripts or extracted borders:

  1. Just flatten a Copy of Your target Surface
  2. Use _FlowAlongSrf with the copied Surface, Object and Target Surface. Done.

@JanRuben How do you flatten the surface exactly the same size as the curved one?

I did this simply with the _SetPt command with options “Z” only and World Coordinate System. This method won’t work in all cases but will work in this particular one where you have no overhangs. So your Referencesurface will have a similar UV-Space as the Targetsurface: Note the uneven spaced Isocurves…

Yeah that works the same xD Same result so maybe even easier.

Thanks all

I just happened to do a video on this last night:

Covers the flow along aspects.

@jim, thanks. I’m excited to play with Pascal’s script. I use a half dozen of them but missed that one.

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Got the flowalongsurface part in vb.net script but want to trim the sides automatically and keep the mid part (see pic):

So I meshoutline the big surface. Is there an easy trim function in VB.net or should I use split because I cant find anything about a trim function in Geometry.Transform. Anyone can give me some tips about this?

Oke got somethings. I’ll just split, selboundary with inverseselection and delete :slight_smile: