MergeCrv Tutorial on V7 WIP

This is part one showing how powerful history can be with MergeCrv and CurveThroughPolyline. I plan on recording more demos as I can.

Shank Template Files Using MergeCrv and CurveThroughPolyline:

Shank-Loft-YMirror.3dm (142.4 KB)
Shank-Sweep1-TopBottomBlend.3dm (186.3 KB)

The toolbars and plugins that were discussed:

Original feature request:


Thanks Eric!

Eric, looks like you work hard to make this software work better for you. Also nice that you share your ideas and methods.I keep a lookout for your posts because of how you work with this software. Great work! —-Mark

Hey Eric,

I’d like to +1 your feature request for a Rhino tool to array tapered objects spaced with a consistent gap, with History. It would be even better if it could work along a curve on a surface as well.

As you noted, Rhino currently can’t array tapered objects, and can’t distribute objects along a curve and/or on a surface. Armadillo can do both, but doesn’t have Rhino History.

This kind of tool would be a HUGE benefit! Even if the spacing isn’t perfect, if it’s History enabled, then we can tweak the parent objects and fix any odd spacing issues on the Children.

Great video! It’s fascinating to see what you’re doing with the “universal shank” idea.

Pete, Mark, Mike,

Thanks for chiming in on the McNeel forum. It’s important I’m not the only one from the jewelry forums talking about our workflows here. Parts 2 and 3 with more novel uses are coming after Christmas.

@pascal, all the comments from the other forums and YT mention better tools for stone layouts. The major issue revolves around controlling the reference frame for space morphs.

I talked to @dale a good bit last year trying to figure out how to control the surface parameterization for FlowAlongSrf. That would be optimal, but it’s extremely difficult.

I have a new plan I will detail soon, but it feeds a surface normal into _Flow. That’s what @Jarek is doing with Armadillo.

Rhino FlowAlongSrf mapping base UVN to target UVN:

Armadillo creating a target plane using point on curve + nearest surface normal, then orienting plane to curve normal:


I went ahead and wrote it up.

1 Like

Christmas miracle for a Christmas delivery. I saved at least an hour on a last-minute request to change a flat band into a cathedral shank with trellis head.

Took less than 60 seconds to update the universal shank, but now the shank has really inconsistent parameterization and is a terrible FlowAlongSrf target…

…but the new history enabled rebuild ( RH-56271) fixed that issue in another 60 and gives me all the history I need to make further tweaks.

Rebuild DeleteInput=No

And there’s even some MergeCrv (RH-45817) goodness hidden in the trellis head.


On top of being incredibly grateful, I’m also incredibly optimistic. As soon as we get RH-56171 we will be able to use this workflow again in the same file for the matching band. And RH-56357 will give the same full history tree for easy modifications.