# Rigidbody on limbs pulls character all over

Discussion in 'Physics' started by ShaunUnity, Sep 13, 2019.

1. ### ShaunUnity

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Dec 8, 2017
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I'm making a game where two teams of AI fighters attack each other with swords and shields. All the fight moves are controlled by an animation.

I wanted to use physics on the sword and shields - meaning, I want the shields to actually block sword blows. But when I attach kinematic rigid bodies to the weapons and the characters start moving their limbs it makes the characters move all over the place like the weight of the weapons is pulling them from side to side.

I was under the impression that setting a rigidbody to Is Kinematic would prevent this.

2. ### kdgalla

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Mar 15, 2013
Posts:
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It should. Do you they have colliders that are overlapping? That could also cause unwanted movement.

3. ### ShaunUnity

Joined:
Dec 8, 2017
Posts:
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As in colliders on the same character, yes. There is a non-kinematic box collider on the main body that the shield passes through from time to time.

4. ### kdgalla

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I thought of something else, did you turn off "use gravity" on your rigidbodies? I would have thought kinematic rigidbodies would ignore gravity but I'm not sure.

5. ### ShaunUnity

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Dec 8, 2017
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Yep. Gravity is off on the weapons.

6. ### kdgalla

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Mar 15, 2013
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Going back to the colliders- if you set them to "trigger" does that solve the problem?

Generally if you have objects with overlapping non-trigger colliders and they both have rigidbodies then they will constantly register a collision, causing them to move. On the otherhand, if you have two objects with overlapping non-trigger colliders and you have one rigidbody on a parent object then the two colliders will act as a "compound collider" which might be what you want. I don't remember how it works for kinematic rigidbodies, though.

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