Why do Constraints move?

I was reading over the documentation on Constraints for 2019.3b, and nowhere in the Aim or LookAt Constraints did it mention that the game object physically moves, only that it rotates. Yet if I have a rigidbody component attached to a gameobject with a separate constraint component, the gameobject moves towards the constraint component source. If I remove the rigidbody component, then it simply rotates to face the gameobject as expected.

If adding a rigidbody causes a LookAt or Aim constraint to move toward the game object, I’m curious why this isn’t mentioned in the documentation? Or if someone could kindly explain to me what I might be doing wrong or not understanding, as I’m new to Unity.


@heronww ·

Hello. Did you or anyone find the answer?
I have the same question here.
I guess the reason is rigidbody can’t apply with constrains because one is using force system and the other is manipulating transfom directly. But I really don’t know it’s true or not.

Hi mate. Don’t meant to dishearten you but I ended up concluding that Unity is currently suffering from a catastrophic amount of feature creep where there’s too many features, too many ambitious roadmaps, not enough documentation, too many bugs and too much “magic”. I’ve decided I’ll return in a couple years and see if they can scale back the feature creep and just focus on releasing a core, suitable game engine instead that’s designed for making games.