Transform.position is being changed, but character is not moving back to it when told

Question

I'm trying to make a respawn point for my car to jump back to if it presses a button. I can see, using the Print() lines, that all the variables are correct and the methods are being triggered when expected.

But the car doesn't go back to the spawnpoint like I want it to. The velocity part seems to take effect and work ok, but the rotation and position part does nothing.

I tried several different variations of this code (ie. GetComponent<> and setting a public player variable (even though I am already in the player with this script)).

Like I said I tried making a public Player and setting the transform p and r on that. I also tried GetComponentByParent<Transform> and setting like that. I've tried a few other variations of that too. And I get the same results.

Here is the bit of code I think is relevant, if you actually need to see more please let me know.

public void OnTriggerExit(Collider other)
{
    if (other.gameObject.tag == "RespawnTrack")
    {
        print("respawn point added upon Trigger Exit");
        recordedTransformAtRespawnTrack = transform;
        recordedVelocityAtRespawnTrack = rb.velocity * 0.25f;
        print("rotation was: X,Y,Z=" + recordedTransformAtRespawnTrack.rotation.x + " , " + recordedTransformAtRespawnTrack.rotation.y + " , " + recordedTransformAtRespawnTrack.rotation.z);
        print("position was: X,Y,Z=" + recordedTransformAtRespawnTrack.position.x + " , " + recordedTransformAtRespawnTrack.position.y + " , " + recordedTransformAtRespawnTrack.position.z);
    }
}

public void CheckToRespawnCar()
{
    if (isRacing)
    {

        if (CrossPlatformInputManager.GetButtonDown("Jump"))
        {
            print("RESPAWN TRIGGERED BY PRESSING BUTTON");

            transform.position = recordedTransformAtRespawnTrack.position;
            transform.rotation = recordedTransformAtRespawnTrack.rotation;

            rb.velocity = recordedVelocityAtRespawnTrack;

        }

    }
}

Answer 1

What you are doing is making a reference to the transform object rather than a copy of it's values.

So when you copy the values later you're actually copying the current values as recordedTransformAtRespawnTrack points at transform.

C# makes a distinction between class (referenced objects) and struct (by-value objects).

Transform is a class. Which are referred to (using "pointer"). a=b; creates a copy of the reference (the "pointer") to the object.

Vector3 and Quaternion are structs. Which are copied. a=b; copies the values of the object.

This:

        transform.position = recordedTransformAtRespawnTrack.position;
        transform.rotation = recordedTransformAtRespawnTrack.rotation;

Is the same as this:

        transform.position = transform.position;
        transform.rotation = transform.rotation;

You need to save position and rotation themselves:

Vector3 savedPosition = Vector3.zero;
Quaternion savedRotation = Quaternion.identity;

public void OnTriggerExit(Collider other)
{
    if (other.gameObject.tag == "RespawnTrack")
    {
        print("respawn point added upon Trigger Exit");
        savedPosition = transform.position;
        savedRotation = transform.rotation;
        recordedVelocityAtRespawnTrack = rb.velocity * 0.25f;
        print("rotation was: X,Y,Z=" + recordedTransformAtRespawnTrack.rotation.x + " , " + recordedTransformAtRespawnTrack.rotation.y + " , " + recordedTransformAtRespawnTrack.rotation.z);
        print("position was: X,Y,Z=" + recordedTransformAtRespawnTrack.position.x + " , " + recordedTransformAtRespawnTrack.position.y + " , " + recordedTransformAtRespawnTrack.position.z);
    }
}

public void CheckToRespawnCar()
{
    if (isRacing)
    {

        if (CrossPlatformInputManager.GetButtonDown("Jump"))
        {
            print("RESPAWN TRIGGERED BY PRESSING BUTTON");

            transform.position = savedPosition;
            transform.rotation = savedRotation;

            rb.velocity = recordedVelocityAtRespawnTrack;

        }

    }
}