Tween along curve

Dale at mcneel wrote this cool script for tweening down a curve.

make a path, make a start curve and a different shaped end curve and >poof< tween along a curve!

command ‘ArrayCrvTween’

download and drag and drop to a rhino window to load-


enjoy! ArrayCrvTween.rvb(4.2 KB)

Here is a permanent link:

Greetings Kyle, @theoutside and @dale

This is intriguing but I am wondering if you can give us an example of how to use it?

Thank you.

Off the top of my head, start with a circle at one end of a curve and a rounded rectangle at the other end of a curve, tween along curve between them and then loft the result with history…use it to make a cool handle for a tool or something like that. adjust the curves in between to sculpt the loft with history- can use to to create a smooth shape that would be tough to lay out by hand-

thank you

Thanks so much for this script. I’m having some difficulty tweening correctly, hopefully, one of you may be able to troubleshoot with me. I’m attempting to tween the two blue rectangles along the orange curve. It’s subtle, but as you can see, the blend is not correct. Am I missing something obvious here?


Can you post your 3dm file?

– Dale

If the shape doesn’t change what would be the reason to use tween vs array?

Dunno if you use Grasshopper, but Pufferfish has components for tweening along curves.

Tween along (9.2 KB)

Sure thing! File attached. My rationale for a tween is to ensure the shape hits a specific position on the other side of the curve. You can see that ArrayCrv “freeform” is not giving me the result I need. Is there another way?

And yes I do use Gasshopper! I will check it out, thanks. Assumed this could be solved easily in Rhino…

ArrayCrvTween_vs_ArrayCrv.3dm (277.0 KB)

Pufferfish is great! I was able to fix it simply by rebuilding the path curve. :grimacing: Although, I don’t really know what was wrong with the original curve to begin with. Perhaps this was why I was getting weird results with ArrayCrvTween. Thanks for the help.

EDIT: The new path curve does not seem to solve it on the rhino side, still getting the same results with ArrayCrv and ArrayCrvTween.

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