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I was following a tutorial for making a realistic chain where you use Rigid Body Physics to make a chain fall on a plane. I'm trying to use this technique in one of projects, but I can't get it to work. I tried doing the tutorial in a new project and it still didn't work.

I am using torus objects and duplicating them to make a chain. I select all of the objects and go to the "Physics" tab in the Tool Shelf (T menu) and press "Add Active". I then go to the "Change Shape" drop down and choose "Mesh". When I play this it takes forever to simulate, and about 4 frames in, the links in the chain start to separate as they fall. I want them to stay together (which works fine when I do this in a new project using only the chain mesh).

enter image description here

TARDIS Maker
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Josh Firicano
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    Have you applied the scale with [Ctrl]+[A]? Also try scaling everything up (and then applying the scale again). – PGmath Aug 23 '15 at 00:50
  • What does the scale do? I just selected all the links in the chain and pressed Ctrl+A and the pressed scale. After that I chose add active, then changed the shape to mesh and they still fell apart :( Thanks for your comment though. Something is going on here because this works fine when I do it in a new project. When I add it to this project it just doesn't work and I can't find out why. – Josh Firicano Aug 23 '15 at 00:58
  • See here for more on applying scale. Did you try scaling up the chain links? – PGmath Aug 23 '15 at 01:00

2 Answers2

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Try making your chain links dramatically bigger. Blender has a problem with small objects with rigid body physics. Hope this helps!

Ray Mairlot
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jo99blackops
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  • WOW that worked. That really sucks though because it looks ridiculous with chains that large. Thank you for figuring this out though. – Josh Firicano Aug 23 '15 at 01:00
  • You just need to move your camera farther away and also zoom out your view alot. When working with Rigid Body, get ready to make everything on a larger scale. :) – jo99blackops Aug 23 '15 at 01:02
  • P.S. Please mark my answer as your answer if it worked :). – jo99blackops Aug 23 '15 at 01:03
  • I actually found a work around. I just scaled the chain back down after it fell. Thanks so much for the info! – Josh Firicano Aug 23 '15 at 01:03
  • I'm glad it worked! – jo99blackops Aug 23 '15 at 13:14
  • I find that you can simply set suitable Unit Scale; Go to Properties Editor - Scene Properties - Units and set Unit scale to e.g. 0.001. I was able to create ball and chain scene where the length of the chain is about 42 mm and a single chain link has measurements around 4x3x0.5 mm. I did have to increase the Rigid Body World "Steps per second" to around 200-300 to get the simulation work perfectly, though. – Mikko Rantalainen Oct 20 '20 at 14:02
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Your links are scaled way down. Most likely, if you apply scale it will work much better for you. I had the exact same problem until I simply applied the scale to every object that was interacting with each other. Simulations in Blender work best and most accurately when scale is set to 1. You may not even have to scale everything up so big that it looks ridiculous.

jfriend
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