Simulating curved folding without planar quads?

[zoster (Andrei Raducanu)]

Hey all!
I know this is a bit specific, but I was wondering if there is a more advanced way to simulate curved folded designs (not necessarily in Grasshopper) that doesn’t use the rigid origami quads method, and therefore ruling lines that have to be implemented before the folding process, but rather something more close to real life, where you have the folding curves, pull on some points on the surface and the shape emerges (and the ruling lines are basically defined by the movement, not set beforehand).
Thanks a lot!

(maybe @DanielPiker knows some tricks, sorry to tag you like that)

[encephalon]

do you have any kind of example? right now i might be misunderstanding that completely.

if you want something simple non grasshopper like, you can use loft with history. the more curves you integrate the more control you have. you can use EditPtOn instead of PointsOn to get a more direct feeling if you wish.

[DanielPiker]

It’s true that predefining the ruling lines limits the folding.
Lots of curved folding actually relies on the ruling directions changing as it folds, which the planar quads method can’t capture.
Using a triangulated mesh as a shell can sometimes be a better way. See these threads on this:

Tessellation Origami

One tricky thing about curved folding origami is the interaction of the mesh edge directions and the ruling lines (paper stays very close to a developable surface, so the curvature in one direction will be zero). If you know the ruling directions, you can model curved fold origami as thin planar quads. (See this paper: http://graphics.stanford.edu/~niloy/research/folding/folding_sig_08.html) However, what makes it tricky is that the direction of these ruling lines often isn’t obvious from the …

Plywood Strips twisting and bending simulation

Hi Sotiris, Sorry @agakorz14 I missed this discussion the first time around. For an initially flat strip like this where the thickness is very small in relation to the width, the deformed shape should closely approximate a developable strip. There is unlikely to be significant in-plane bending or stretching. If we are just considering the shape it bends/twists into for a certain combination of end positions/orientations, and it is not significantly affected by self weight, then this shape doe…

[DanielPiker]

or this one:

Hinge component

I realise this isn’t exactly what you were asking about, but thought I’d share the example anyway as others might find it useful: _ curvecrease_example.gh (19.2 KB)

edit - I just realised that example is from before TriRemesh and using the buggy old remesh. Here it is with that bit updated:
curvecrease_example.gh (21.3 KB)

[zoster (Andrei Raducanu)]

Hey, Daniel! Thank you for the great references, I waited to reply after I actually had some time to read them and test the linked definition. My understanding is that the definition you linked along with the video, doesn’t use Rabinovich’s angular constraints. Am I wrong? I see it only uses a plastic and a “normal” hinge component (alongsiode the EdgeLengths goal). Do you perhaps have one where these are implemented? (the video seems to show something that uses an orthogonal geodezic net, though curvecrease_example.gh uses a triangulated mesh. If you have the time to clear it up a bit, it would be greatly appreciated!

Thanks again!

[DanielPiker]

Hi @zoster

The curvecrease.gh example is using the triangulated mesh+hinges approach, but if you look in the ‘plywood strips’ link in the post above, there is a definition there which shows the use of the non planar quad mesh with angle constraints like in the IGL papers.

[zoster (Andrei Raducanu)]

Thank you! don’t know how I managed to miss it…
I am guessing one that can adopt creases as well is not yet developed.