Grasshoper equivalent for "Array along curve *on surface*"?

Hi friends,

So what is the Grasshopper equivalent for “Array along curve on surface”?

“Array along curve” is there but “Array along curve on surface” isn’t…

Am I missing something? (:

Thank you,



ArrayCrvOnSrf is a “high-level” or “compound command” that probably does a couple of different “lower-level” operations behind the scenes, whereas most Grasshopper components are more “low-level”, meaning doing - superficially speaking - less complex jobs, if that makes sense.
This means that if you break the problem down into smaller parts, you can probably easily replicate the behaviour in Grasshopper!

For instance, you obviously need a surface and a surface curve to start with, as well a third geometry to distribute.
You can divide the curve by count, length, or distance to get points defining a curve array. Then look for the closest point on the surface of each of these division points, and use the resulting uv-points to evaluate the surface. This will give you normals, planes/frames, etc.; all the informations necessary to place/orient a third geometry that you want to replicate along the curve on the surface.

Thank you @diff-arch, yes, as a programmer this was clear to me but my method was missing a step that you’ve mentioned so thanks again, I got it now!

I was also thinking/saying there could/should be a simple component for it :slight_smile:

If this means C# then I could post here an indicative start on that matter (but the main challenge is the management of coordinate systems [Planes] if you want to do a well “controlled” classic PlaneToPlane Transformation … like placing road sections in a given terrain etc etc).

Hi @PeterFotiadis, That was actually a reply to diff-arch’s “high/low level” explanation… but what you said is interesting as I’m mostly a C# programmer and also thought about that route… so I wouldn’t mind taking a look… Thank you :slight_smile:

Well … in order to avoid an abstract demo (solely for Academic purposes) provide some hints about what are you after: how you get the path (Curve) , what sort of animals you want to Transform (I assume using classic PlaneToPlane) and what is the final target.

I’m just experimenting for now :slight_smile: running spheres along a curve on a surface, getting the curve from Rhino…