Unfolding with Compound Transforms

Cross posted here.

UPDATED TO WORK WITH VERSION 0.8.0010

Lately, in some of my work I have been investigating unfolding complex forms with Grasshopper. The newest release of Grasshopper enables the use of Compound Transformations, which makes it possible to quite efficiently unfold strips of planar surfaces. In the past I have had to use pepakura or other similar utilities to perform the unfolding outside of Rhino, or alternately a slow faux-recursive method where I essentially unfold one segment of the polysurface at a time.
Below are a few definitions making use of this new capability.

The first, here (unfold_surface_strips.ghx), simply takes a list of surfaces that adjoin each other at an edge and unfolds them flat.

The second (triangulated_surface_strip_tool.ghx) utilizes the same processes in the first to unfold a triangulated version of an input surface. Strips can be evaluated in the U or V direction.

Finally, with the right settings on the same definition (setting V divisions to 1 and U divisions to some high number) it can be used to substitute for the UnrollSrf command in Rhino with a high degree of accuracy. This is an improvement in efficiency and accuracy over my earlier Unroll definition.

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Comment by tiqué on June 17, 2012 at 11:19pm: Andrew can you please also tell how to put name tags and angle tags on the same unfold pattern.

Comment by Derenik Baghramian on February 3, 2012 at 12:08pm: I have some surface like this.i want to unfold it ho i can do it?

Comment by Derenik Baghramian on February 3, 2012 at 12:08pm

Comment by Ken Sit on November 21, 2011 at 4:50am: hi andrew,

thanks for the script. I'm a little lost as to how you operate the script. I've been trying to unfold a surface that's already separated into different strips like pepakura but having no results out of it. could you please give some direction has to how to operate the script?

thanks.

Comment by RWNB on May 30, 2011 at 10:54am: thanks for sharing!

Comment by Andrew Heumann on May 29, 2011 at 8:46am: hmm, it shouldn't matter where you download from; my blog links to the exact same place for the download. In any case I'm glad you got it working. My definition allows you to unfold a sequence of surfaces in any order you specify; if you don't care about the order and just want it to unfold an entire polysurface, the adapted version of Steve Baer's python script will do the trick very efficiently.

Comment by Archieboy on May 29, 2011 at 4:33am: thx, andrew, I think I download it at the wrong place, I tried the one on your blog and it is working succesfully. It is exactly what I'm looking for. thx!

Comment by Archieboy on May 29, 2011 at 4:15am: Hi Andrew, this window pops up when I tired to open your first unroll polysurface script. And I can open your second script perfectly. I'm using Rhino 4 sr9 and GH 0.8.0010. And for the second question, is this a joined polysurf or a series of srfs which you have to select them one by one in sequence? All I want to do is to unroll a polysrf, say a tetrahedron, if I use unroll command in rhino, it will unroll every single srf, however, I want to do something similar to your first post, linking adjacent srf together and then I can fold them later on.

Comment by Andrew Heumann on May 29, 2011 at 3:21am: sorry, archieboy, can you be more specific? On my machine the first definition opens without problem. What issue are you experiencing? I'm also not sure I understand your second question - this definition will unroll a polysurface, if perhaps not quite as automatically as the Rhino command. If you have Rhino 5 and python, you should check out Steve Baer's script here... it currently handles only a single surface at a time but can be easily adapted to work on polysurfaces (just remove the "[0]" after breps in line 8)

Comment by Archieboy on May 29, 2011 at 1:45am: There is something wrong happen to me when I tried to open the first script. Do you also have some suggestions on unroll polysurface?