rigidbody.MovePosition is not behaving as it should

Questions & Answers
1

Hi

I am working on a moving platform that needs to carry a rigidbody object. I figured rigidbody.MovePosition would work great but apparently not. This is my code:

rig.MovePosition(newPos * moveSpeed * Time.deltaTime);

newPos = Vector3. moveSpeed = float.
Doesn’t matter if I put this in Update or FixedUpdate, it gives the same result currently. (Yes, I know I should put it in FixedUpdate) So the newPos is set to 10, 0, 3 but it moves to approximately 1.6, 0, 0.5. I have no idea why. There is nothing in the code that sets it to do this.

Now for the rigidbody settings:

  • Use gravity = false
  • Is Kinematic = true
  • Interpolate = Interpolate
  • Collision Detection = Discrete

Can someone tell me what’s wrong and why it does this?

Thanks in advance!

2

Vector3 newPos = new Vector3(10.0f, 0.0f, 3.0f);
float speed = 5.0f;

void FixedUpdate(){
    if(rig.position.x <= 10){
    Vector3 direction = (newPos - transform.position).normalized;
    rig.MovePosition(transform.position + direction * speed * Time.deltaTime);
    }
}
3

I’ll hazard a guess your moveSpeed is set to 10?

Take newPos.x and assuming you are running at 60FPS

1/60 = 0.016666 = Time.deltaTime

10 * 10 * 0.016666 = 1.6666

For newPos.z

3 * 10 * 0.016666 = 0.49998

You need to specify your current position and add some distance to it. The other answers deal with this but you didnt get an explanation.

4

If Your Rigidbody has parent ,then the parents scale should be (1,1,1). And even if it’s parent is scaled, if you use Rigidbody.MovePosition(10,0,0) it will move rigidbody 10 meters in world space you just gonna see different values in Inspector, because of scaled parent.