# Move rigid body gear using particles

So I was trying to make a particle simulation where the particles collide with a fixed gear that rotates when the particles collide with it.

# The gear

As you can see I have locked the locations of the gear and limited the rotation to the Y axis only in the transform locks in the object settings, I also added rigid body active and collide physics to it (collide because I need the particle system to collide with it).

# Without the particle system

The cubes are active rigid body objects that also have the same transformation lock settings as the gear, and the groundfloor is a passive rigid body. In this case we can clearly see that the gear rotates when colliding with the cubes

# Now with the particle system

I added a plane and added a particle system to with the particles set to object (Cube), as you can see the particles surely collides with the gear but the gear doesnt rotate like it did previously when the same thing was done with cubes.

# So how do I make the particles collide and rotate/move a rigid body object ?

• Possible duplicate of Is there a way to make particles behave like rigid body objects? Sep 9, 2017 at 3:36
• No, this question provides the solution as copying the properties to other rigid bodies or making the duplicated rigid bodies real. My question was to make the particle system MOVE the rigid body gear. Sep 9, 2017 at 9:32
• One answerer does stipulate they tried exhaustively to make particles react with rigid bodies directly. As a workaround dropping the particles over the animation produced by rigid bodies could probably look ok.? A request, could you post your blend please Sep 9, 2017 at 11:02

I was just looking into this over the weekend. I believe a recent tutorial on Vit Prochazka's youtube channel has the answer you seek. I'd love to try and explain it here, bit it is quite convoluted and it requires the Animation Nodes add-on.

Seems an elegant solution though, I hope it helps:

• Sure it's not just an animation nodes way to set up the "without the particle system" as shown in question? Oct 3, 2017 at 10:25
• The tutorial I linked shows how to use a particle emitter to emit rigid bodies... which I thought was the aim. Apologies if I have led you astray, but it does use the particle emitter (but the physics from the rigid bodies world). Cheers! Oct 6, 2017 at 8:07
• Strictly speaking it is just an animation nodes way to set up "without the particle system" except that it allows the rigid body objects to be emitted throughout the animation - rather than all having to exist on the start frame as shown in the question. That said, it would be better if the answer could include details of the steps needed to set this up rather than effectively being just a link answer. Jan 23, 2018 at 21:45
• Maybe, although I think it would just be trying to re-invent the wheel in this case... to write this process out here would be very lengthy and very time consuming, and the link provides all the info effectively. If someone wants to take a few hours to write it out, feel free. Or, just click the link... I'm sure you won't break a finger or anything in doing so. Feb 16, 2018 at 0:57