Construction advice and tips needed! Help!



Hello Discourse Mcneel Community!

I was handled a file (.pdf attached) and tasked to create a 3D model of it.

If there is any one with recommendation and tips to how I should go about using the construction lines to build it into a 3D model using Rhino3D. I tried building it but the construction lines are really confusing me and when I am extruding it and I can’t seem to get it into a full solid model.

I have a few images on how the example should look like. Would appreciate if anyone could give me advice to it. Thank you

JN02039_Ryman Skinny FSDU - Die Lines.pdf (15.9 KB)


pictureframe command would be useful to create your outline curves


No need to use picture frame, you can import the pdf into Rhino, as you already did. Don’t try to start by making it a solid. My workflow would be to create surfaces for each individual panel, and fold them up using Rotate3D . Then I would use OffsetSrf with the option “solid” to give it some thickness. You should realise that folds in sheet material are notably difficult to mimic, how the material behaves is dependant on thickness, consistency of the material, indentation of the fold line etc. But for thin materials I think my method is sufficiently close.
To create a surface you will need a closed and planar curve to begin with. Since the curves are imported from a 2D file, Planar is guaranteed, however Closed is a different matter, which is also why you did not succeed in creating a solid.

  • select all lines and change the property “color” to “by layer”, to give a clear indiction of which layer they belong to.
  • select all lines and Explode
  • create two more layers “construction” and “surfaces”, and give them contrasting colors.
  • select the curves that define a single panel (as a minimum, more is ok), right-click on layer “construction” and choose “copy objects to this layer”
  • make construction the active layer
  • make Default invisible
  • work the curves such that they connect to or intersect with each other. Now this is easier said than done. I use connect and go around the circumference to connect all curves. There may be some lines that are overlapping, so I use CurveBoolean to generate a new closed curve with the original lines as boundaries. While this new curve is still selected I use PlanarSrf to create a surface.
  • move the surface to layer “surfaces”, you can simply change the “Layer” property of the surface.
  • Fold the surface in position with Rotate3D. Most if not all of the folds are 90 deg., so the easiest is to open the Perspective viewport with “Ortho” on. Pick the surface(s), pick two points on the fold and rotate.
  • select all curves on layer Construction and delete those.
  • repeat as before :slight_smile:

Note that there seem to be some fold lines missing on the little tabs.



yes @maxz is correct, apologies I didn’t notice the PDF, and if you are folding this in sheet metal be mindful of bend allowance, there’s a whole bunch information out there around this, one example you can find here


True, but that example deals with sheets of material with a consistent density. When you are talking corrugated cardboard or foamboard (foam with paper on both sides) it becomes a different story. And there is half-cuts and indentation to consider…



yes and different again if you are line bending acrylic sheets, the bend allowance all depends on the material of choice


@yzk.evs Did you get anywhere with this? I am a bit puzzled as to why you were tasked with this as the pictures demonstrate that the real thing already exists? I sounds a bit like 'reversed engineering", but not quite. In that case your task would have been to build a 3D model from the real thing, and work out the cutting and folding patterns…



it worked! Thank you @maxz and @milezee for the detailed explanatory! I am a new(noob) to Rhino. Once again, thank you :smiley: