How do I UnrollSrf command add details. Then make 3d back in original place?

I’m designing the basic shape of something. Then I’d like to unroll developable surface. Add quite a few lines like zip, window webbing flagstitch positions, then place it back onto the 3d model with all these curve lines in place.

Can anyone tell me how to do this, or maybe if there’s a different way which will achieve the same result?

Also I only have Rhino 4.


Hi James,
Check out the command Flowsrf.(not sure if exactly this but the tool is Flow Along Surface)
It allows for geometry to be mapped from one surface (the unrolled for you) to another surface (your original).


Thanks Willem,
I’ve tried it out and it works perfectly!

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Hi James - you may get better results in some cases this particular process (UnrollSrf used as a base for FlowAlongSrf back to the original) if you unroll using UnRollSrfUV.

UnrollSrf_FlowAlongSrf.3dm (70.6 KB)


Hi Pascal,

Thanks for the additional info. I remembered there had been issues brought up about this but did not remember UnrollSrfUV. I think this could be clarified in the help @margaret UnrollSrf should have a mention about UnrollSrfUV and some elaboration on comparison between the 2 commands?

This is a good example of cluttered commands and functionality. Why not add a switch in UnrollSrf to get UV to remain. Why in the first place can it not remain?

Then there is Smash Squish and the 2 versions of UnrollSrfs…
V6 should have this more condensed and may I opt for a single dialog/toolset to flatten geometry.
Imagine a flatten dialog where one can choose between the 4 different approaches, including settings for tolerances and comprehensible feedback of resulting deviations.
I know from a coding perspective UnrollSrf and Smash are miles apart, yet for a users these are very similar and when combined in a single GUI it’s much easier to explain about differences and tackle ignorance.



Hi Willem-
Oringally, in V5, there was only UnrollSrf- this was changed, a lot, from the V4 UnrollSrf to make it more accurate and reliable. Included in this change was the change to how UV is handled- as I understand it, this was a necessary change.
What we learned was that a good number of users had been using UnrollSrf, in V4, in this FlowAlongSrf workflow, and they howled, understandably enough… so V4’s UnrollSrf was reinstated, asap, as UnrollSrfUV. So, that is the series of events as I remember - I do not recall if we discussed making KeepUVs a command line option in the newer UnrollSrf but this seems dangerous since the results, in terms of unrolling accuracy, may very well be worse. So there we are… I agree that it is a bit messy.


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Hi @pascal

Do you know if its possible to script UnrollSrfUV in Rhino Common as could not find it as option, either as part of UnrollSrf or on its own. As would be useful to script both in rhino and in Grashopper. @DavidRutten and chance of seeing an unrollSrf and or squish component in Grasshopper anytime soon please.

Being able to set where you are unrolling too instead of the default 0,0,0 would be really useful too

Thanks Matt

I totally agree, more of this:

and less of this:

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