Locking local rotation but keep Parent's rotation

Howdy All,

I’ve got a problem I’ve tried two different solutions on and neither work.

I have this Aerotrim, which is like a human gyroscope. Mine has two rings that each spin on a different local axis, but should also spin in relation to their parent ring.

aerotrim.jpg

120f5005d2d840de7bcb651987db4f3865b0538b.jpeg

In the image we have the stand which is locked. This first ring (outer ring) in from the stand rotates on it’s local X Axis. The inner ring in rotates on it’s local Z Axis.

The inner ring is a child of the outer ring.

That all works, but the inner ring should be locked to the rotation of the outer ring so when the outer ring spins, the inner ring sticks with it. You’ll see a nub at the top of the inner ring. this should always be in the mesh of it’s parent ring. Think of the nub as a hinge.

My first attempt at this was importing a skinned mesh with bones, but I could never get the physics system to play nice.

Any help would be great.

-Sterling

Is this what your after?

ezgif.com-video-to-gif.gif

Crude but thats how i did it if it is.

DevilsD,

You’ve got the general idea, and your suggestion works, but once Physics is employed, it goes to hell. I may have to revisit what I want to do, conceptually. Try it with physics and walk into it. But you’ll need three rings. Lock the outer ring. Limit middle to spin on X and inner to spin on Z.

BTW, if you’re the same DevilsD from YouTube, thanks again for the kind words.

-Sterling

You need to attache the different rings using rotational joints. Do not attempt to set the rotation of the objects manually.
Instead, if you want to spin a particular ring, apply a torque/force to it using physics, and otherwise let the joint/body/physics simulation figure out where things go.

Thanks jwatte, I’ll try that.

Cheers,

Sterling

Yeah im the same guy :slight_smile:

I didnt realize you wanted to simulate physics with this as well.

Doing physics on something like this is going to complicate things quite a lot. I have done some ******** around with creating gear systems and a working clock in unreal using pure physics but it’s certainly quite a headache and prone to failure