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looking to physically simulate a spinning top in Blender. I'm a moderately experienced Blender user, but not very familiar with its physics systems.

https://imgur.com/a/d0mI5A4

At the moment I have the (rigidbody) top spinning using the 'animate' property in the rigid body options, switching it on and off as I rotate the object 300 degrees in Z over 10 frames (similar to this method). Subsequently, the top spins, slows, stops - without wobbling or falling over, which is the behaviour I'm seeking.

Ideally, this should be physically simulated - I've found a few tutorials on replicating this behaviour through keyframed / curved animations and that's not what I'm looking for. I'm hoping to get something like this: https://www.youtube.com/watch?v=x3UEPaJXb6c Any ideas?

---EDIT---

So - my latest version of this project is available here. I've changed some of the settings for the Rigidbody World in the Scene Pane (physics steps to 1000, extended the length of time the physics is modelled for to cover the whole of my animation) and converted the rigidbody for the top to use Mesh for the Shape.

I've resized my top to be approx .36m in diameter, .246m in height.

If the top is placed directly on top of the surface of the 'floor', on 'play' it leaps a few meters into the air before landing, spinning, on the floor.

When the spin stops, the top still stands perfectly upright.

My top still doesn't wobble.

I've inspected some examples of this kinda of project with tops which spin and wobble without needing an initial angle, so it should be possible to achieve the goal of this project. I just can't seem to get it working.

Really would appreciate any help on this!

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  • $\begingroup$ it is possible the mesh is too perfect and won't fall, try ending the rotation half a degree to the side for it to fall falling $\endgroup$
    – J Block
    Commented Jun 29, 2019 at 18:20
  • $\begingroup$ @JBlock - Thanks for the advice, man. Since I initially posted, I've encountered example projects where the top doesn't have an initial angle and yet spins, wobbles, topples, stops just as I desire. Unfortunately, I can't seem to identify what the difference is between my project and the examples. Any ideas are appreciated! $\endgroup$
    – Reverend Speed
    Commented Jul 1, 2019 at 2:20
  • $\begingroup$ @cegaton - Fixed. Ultimately, I needed to upload the image using your dialogue, not try to link to a previously uploaded Imgur file. $\endgroup$
    – Reverend Speed
    Commented Jul 1, 2019 at 2:21
  • $\begingroup$ in blender 2.79 physics was calculated as imperfect but now in 2.8 for now it seams to be changed. $\endgroup$
    – J Block
    Commented Jul 1, 2019 at 4:38
  • $\begingroup$ As Fin notes below, I had moved the origin to the bottom of the spinning top as this was my usual procedure with characters in games. See his answer below for solution - I also had to move the COG to the box centre...! $\endgroup$
    – Reverend Speed
    Commented Jul 1, 2019 at 22:38

1 Answer 1

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The main issue is that in RB sims the center of gravity is assumed to be the origin point of the mesh, in your case you have set this to the lowest point of the mesh (the tip)... therefore perfect balance is achieved..

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