Holding Fractured Rigid Body Objects Together

Support Particles and Physics Simulations
#1

I’ve been working with the newly integrated bullet physics in 2.66 (who hasn’t?), and I’ve come across a problem. Whenever I fracture a mesh using the cell fracture addon, I can’t figure out how to hold the objects together until they are affected by the force of another object and/or force field.

I’ve already tried out the Bullet Constraints addon, but that doesn’t work out (the objects squirm around before they are torn apart by another object, and when they are torn apart by another object, the pieces stick together and react in an almost jello-like fashion, no matter how high I set the Break Threshold).

I’ve also tried turning off the gravity, since I can always animate it. That didn’t work, either. And of course, reducing the mass of the objects to its minimum causes them to slowly float upwards.

Any suggestions? I read through some of the topics in this section of the support forum before posting, so I hope I didn’t miss the same question being asked previously. Help is greatly appreciated!

#2

Under the physics-panel of the rigid body you can use “Enable Deactivation” and “Start Deactivated”. You can then animate “Enable Deactivation” so that it is checked until your bullet is right before your rigid body.
Here’s also a tutorial on shattering glass with the exact same method:

#3

Start deactivated works!
-Thanks

#4

You should take a look at the blender cookie tutorial for using the cell fracture addon. It explains how to do everything from shattering the cup to the fluid simulation. it also covers how to composite it so that it shows the unfractured object exactly until the other object shatters it.

Link: http://cgcookie.com/blender/2012/12/05/breaking-objects-cell-fracture-add-on/

#5

Great! Thank you so much, everyone! I found exactly what I was looking for :smiley: