Why still no Blend Surface in GH?

Just wondering… If it’s a matter of specifying edge indices, you already have to do that with Fillet Edge.

I don’t know whether this helps, but it’s available in RhinoCommon:


You need to pass it lots of arguments. My guess is that that’s probably why it’s not in Grasshopper yet, but who knows! There’s lots of functionality that I use that only exists in the API (and Rhino), and that hasn’t been “externalised” as GH components. You can always do your own, quick, custom components with scripting (Python, C#, VB, ect.).

Actually, the Rhino Blend Surface has even more functionality than the above, things like “influence factors”, for the surface edges, unless the domains are somehow being mapped into those.
Right now, I loft or Sweep 2 Rails through a series of tangent curves to get a blended surface, which requires finding surface normals and curve tangents, taking cross products, and making sure all the points and vectors are aligned properly. It almost never goes smoothly on the first try, usually because of the tangent vector orientations, so it’s not worth putting in a cluster…

My current workaround:

blend surface demo.gh (137.5 KB)
BTW, the Align Curve Seam component comes from Pufferfish


Yes, it seems like the first slider refers to the normalised domain of the first edge and the second one to the one of the second edge to blend to.
Position, Tangency, Curvature are also covered by the continuity0 and continuity1 arguments.
To me it seems to be pretty much all there. Some functionality might need some extra lines of code.

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