I would like create a simple animation; Two spheres at a given distance each with a magnetic moment such that they are attractive. i.e. that when you simulate/animate, the spheres should come together, slowly at first and then rapidly. I imagine this should be possible with the physics engine.

I tried going to 'Physics' section for each object and create a 'Force' with a 'Point' shape, along with a 'Sphere' Falloff to the third power (Both Z). Also, reading through the manuals, it seems that both objects would need to be 'Soft Body' in order to interact with environmental forces, is this correct?

Overall, It doesn't seem that my program is working, and I would like to actually use the physics engine to create this interaction instead of just modeling the motion, if possible. Any and all help is greatly appreciated. Thank you!


1 Answer 1


I believe I found the path to start this sort of simulation/animation. I'm still working on it a bit.

If you want to create an object that has the appeal of attractive and repulsive forces, it seems that adding a 'force field' within the physics tab of the object does not result in the desired motion. I've found that if you have an object AND a force field separately (and make them have identical centroids), you can use the parent/child hierarchy to obtain the desired affect. The key is that the rigid body object must be the parent, so that the force field will follow the parent.

Shown is a picture of two cubes with force fields attached as children. The force field(s) were given the following values: Strength -> -5 (attractive), Fall Off Power (shape = sphere) -> 1, and also direction was set to 'Both Z'. Also, for the object, a Rigid Body Mass -> 0.01.

This has the beginning of the desired affect. Please feel free to add comments to this answer if you have any further insight into the matter. The next goal is to correctly add a north pole and south pole to the Magnet so one can simulate the desired effect under rotations, etc. Thank you.

Two Cubes (parents) with force fields (children)

  • $\begingroup$ I know I asked for sphere's initially and the answer uses cubes. It was just simpler to create, play with, and test. But should be the same concept. Thank you. $\endgroup$ Commented Dec 28, 2015 at 23:33
  • 1
    $\begingroup$ Kudos for staying within the Physics engine and trying to add multipole moments! $\endgroup$
    – uhoh
    Commented Dec 29, 2015 at 10:37

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