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Metal tape measures behave in a very interesting way. When they are held out horizontally, for some length, they bend, but when they bend, both segments around the bend stay absolutely strait and the bend forms a fairly tight crease. I've been trying to create something to this effect to create a simulated corn leaf (part of a larger plant), and got stuck. How can I make this effect (for the tape measure)?

My best result so far is this: enter image description here

Here is the blend file for testing:

Side note. I am only looking for a simulation solution. Not a rigging one.

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Plastic deformation & Stiff quads

enter image description here

I made several changes to the provided Blendfile to achieve this result.

I'll try to summerize them focusing on the most important ones in a qualitative way, as to make a simulation look good what matter is the "whole":

  • Stiff quads should be enabled. The option will add to the face a "skew resistance", as material elements in the real world have. This way we ensure that the tape has more chanches of keeping his shape
  • Springs strenght increased (almost 1). Metal have quite big elastic deformations compared to other materoals, but the deformation of the elements at the simulation's scale is almost none, so we should make the springs between the faces as rigid as we can.
  • Spring Damp lowerd (and Goal Dampening too). Arbitrary dampening factors usually kills the simulation features in favor of its stabilty. I would generally try to keep them as low as possible.
  • Some Bending resistance. As you already did, must be present in order to give some consistency to the structure.
  • High Plastic Deformation factor. This is probably the key of the whole simulation. While the other feature were all made to give resistance to the tape, this is what brings it to the "breaking point". If enabled, each polygon will keep the occured deformation. Step by step, the structure is falling, bending the wings of the truss toward the outside, lowering the momentum of inertia of the section in the area near the fixed part, till it became so little that the section cant' resist anymore and the section becomes a hinge.

Other minor changes:

  • Geometry of the object (shorter and more compact section)
  • Resolution of the object (less polygon to have more control upon them and faster baking time :P )
  • Mass of the Soft Body.
  • Initial rotation of the bar (15°) (to increase the folding visibility)
  • Post simulation modifier & Matcap... for "beauty's sake"

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I would animate a cube underneath your tape measure mesh. This would give you the tight crease that you are looking for. You may have to play the animation backwards depending on your intended effect. (Don't render the cube).

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  • $\begingroup$ "I am only looking for a simulation solution. Not a rigging one." - Animating a cube counts as a rigging one, The only thing I wish to animate is the tape, not extra objects. Besides, the tape is still going to flop around with the settings I currently have. $\endgroup$ – GiantCowFilms Jan 6 '16 at 20:37

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