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So I have customized this chain that I'm looking forward to animate. I have seen a bunch of videos of how others make it and followed every possible lead: Increased scale, increased mass of some links, increased steps per second (300), assigned material mesh, even played with gravity...

i've spent 3 whole days on trying to improve it but it still doesn't work, as the second link always tends to break, or, the whole chain falls off its anchored hook (active-non-dynamic). Suspicious of my chainlink, i tried to mix it with regular toruses, and individually they work! But when hooked together, they split.

SO! I can only assume that the chainlinks are too thin, which doesn't really make much sense to me.. Attaching pics below. Any hints? Pllleeeeeeeeaaaaaase!!![aaaaand there goes the second link snapping. it's the only one showing problems, everything else seems falling peacefully (and yes I tried increasing the mass to 5oog; and the steps per second at 280 as you see next...]2[waaa not working omg kill me]6

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  • $\begingroup$ Could you provide the .blend? It is hard to guess what could cause these problems. Maybe it is caused by the gaps in the links. I'd try to simulate with a closed object and than substitude it with the custom links. $\endgroup$
    – yann
    Commented Aug 31, 2017 at 4:16
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    $\begingroup$ Your links seem to have scale values. Select your objects, hit Ctrl+A and apply the scale. Play with lower margin values, because your objects are quite close to eachother. Make sure, that in the resting position, none of the objects are intersecting or almost touching, they need a little distance. Don't increase the simulation steps to super high values, the problem is definately somewhere else. $\endgroup$
    – yann
    Commented Aug 31, 2017 at 4:31
  • $\begingroup$ oh of course yann, here is a link to the actual .blend doc drive.google.com/open?id=0B_etny9LYl5uRldzQ3pqbV9BcTg $\endgroup$
    – Edgar Mosa
    Commented Aug 31, 2017 at 17:04

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enter image description here

I looked at your file and made out some problems.

  1. Scale was not applied. For any kind of simulation, you would want your scale values to be 1, 1, 1, so after you scaled an object in object mode, hit CtrlA and choose 'scale' to apply it.
  2. The objects were very large. In the scene tab choose a unit system (metric or imperial) to get an idea of the overall scale of your objects. Once I got them ready for simulation (step 3), they were falling very slow, because they had to travel several meters.
  3. Keep your topology clean. Something went quite wrong with your objects, the topology is completely messed up. It also is very dense, that caused your long simulation times. (The numbers of verts are for the whole scene)

enter image description here

  1. The collision margin was way too high. That caused the links to "jump off" as soon, as the simulation started.

What I couldn't fix is the jittering. To make it work somehow, I dialed down the gravity influence of the rigid body world, but that cannot be the solution. Could anyone take a second look at the files and explain, why the jittering is happening? Also: the solver somehow has problems with the uppermost hook. I removed the rigid body collision from that one and placed some cylinders. Whenever you can, I would recommend to use the collision primitives in the rigid body settings. That is unfortunately not possible for your animation, because the objects intersect with eachother.

Here is the (partially) fixed .blend:

I hope this brings you a bit closer to your goal.

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  • $\begingroup$ Oh yeah the links look a lot better! I tried to Add Modifier>Decimate the original link to simplify the mesh and thats why I ended with such a weird topology. How did you fix it? Also, I tried to animate your file, and again, the second link keeps snapping from the top.. The bottom piece is moving weirdly in your gif but I guess that may have to do with the origin not being in its center of mass? $\endgroup$
    – Edgar Mosa
    Commented Sep 1, 2017 at 16:40
  • $\begingroup$ I used bézier curves to recreate the shapes. Then I beveld them (beveling curves isn't related to beveling in meshes, it adds thickness to the curve) and converted them to meshes (alt-C). This gives you very nice and even quads. $\endgroup$
    – yann
    Commented Sep 1, 2017 at 16:45
  • $\begingroup$ I see, that's also how I made them, I just added way too much resolution to them at first. Thanks so much for this! But still, on your new file the piece keeps snapping on the second link, even after checking all your steps.. $\endgroup$
    – Edgar Mosa
    Commented Sep 1, 2017 at 17:02
  • $\begingroup$ What do you mean by snapping? Does it break again? It is all in all very shaky, I hope we didn't already reach the limitation of blenders rigid body system. I hope someone else will have a look at the files, maybe i missed something. $\endgroup$
    – yann
    Commented Sep 1, 2017 at 17:12
  • $\begingroup$ That is really odd. I uploaded the exact same file I made the GIF from. $\endgroup$
    – yann
    Commented Sep 1, 2017 at 17:37

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