How do I fake a tethered object?

Scripting
1

I’m trying to create the idea of a tethered sphere. I have a simple scene with 3 spheres in a box (floor plane and four surrounding wall planes). One sphere is the Player and has a rigidbody component attached. The other two spheres are “tethered” to their positions, but in a way that allows them to “move out of the way” or give-way when the player collides with them, after which they ease back into their initial/target position.

I’m not good enough with physics, to know how to set this up. Does anyone have some pseudo-code for the process or steps for the script?

Here’s what I’m currently testing, and it seems to be doing nothing; though I suspect I’ve got conflicting forces happening here.

    protected void Update() {

        //increment timer once per frame
        currentLerpTime += Time.deltaTime;
        if (currentLerpTime > lerpTime) {
            currentLerpTime = lerpTime;
        }

        //lerp back into position!
        float perc = currentLerpTime / lerpTime;
        transform.position = Vector3.Lerp(startPos, endPos, perc);
    }

   void OnTriggerEnter(Collider other) {
       Debug.Log ("Trigger some movement!!");

      _thrust = 20f;
      _rb.AddForce(0,0, _thrust, ForceMode.Impulse);
 }
2

I would say look into the different joint components. Perhaps a spring or a hinge joint may serve your purpose.

3

Excellent, thanks Brathnann, the spring joint works flawlessly. OMG I’m so excited!!

4

You could, if you want to cheat expensive physics, also just measure the distance between the two objects each frame and if it goes past a threshold apply a force towards one another that scale up the further away it is.