Help with upside-down rotation

Questions & Answers
1

TL;DR Here’s a video of the issue around the 0:05 mark : https://www.youtube.com/watch?v=YtqWx68WJpQ

I’m just trying to iron out some of the issues I’ve been running into lately. Not quite sure why the object does a rotation at specific angles, as if it’s avoiding crossing certain values or something.

The way I have it set up is that there’s a parent which controls the magnetic forces, normal rotation, and other rigidbody forces. On Awake(), a prefab containing the car model and collider is instanced at the origin of the parent.

I’m also running a Cinemachine camera…not sure if that would have any effect on things.
If you have any thoughts about this, I’d be happy to hear it!

EDIT:
Okay, so I have a few functions that handle rotations:

void Update()
{
        //Turning Input
        if (Input.GetAxis("Horizontal") != 0)
        {
            int dir = Input.GetAxis("Horizontal") > 0 ? 1 : -1;
            float amount = Mathf.Abs((Input.GetAxis("Horizontal")));
            Steer(dir, amount);
        }

        currentRotate = Mathf.Lerp(currentRotate, rotate, Time.deltaTime * rotSpeed); rotate = 0f;
}

void FixedUpdate()
{
        CheckMagnet();

        AlignToGround();

        Turning();
}

void Turning()
{
    //add torque relative to the currentRotate value
        rb.AddTorque(transform.up * currentRotate * Time.deltaTime * rotSpeed);
    }

public void Steer(int direction, float amount)
    {
    //calculate angle from current angle in the left or right direction
        rotate = (steer * direction) * amount;
    }

void CheckMagnet()
{

    //Set the mask layer
        mask = 1 << LayerMask.NameToLayer("TrackMask");
    //Check if there is a track beneath the player
        magnetized = Physics.Raycast(transform.position, -transform.up, out magHit, magnetRange, mask);

    //Shoot four rays downwards in four directions
            Physics.Raycast(transform.position + (transform.up * .1f) + (transform.forward * groundCheckDistance), -transform.up, out hitF, magnetRange, mask);
            Physics.Raycast(transform.position + (transform.up * .1f) + (transform.forward * -groundCheckDistance), -transform.up, out hitB, magnetRange, mask);
            Physics.Raycast(transform.position + (transform.up * .1f) + (transform.right * -groundCheckDistance), -transform.up, out hitL, magnetRange, mask);
            Physics.Raycast(transform.position + (transform.up * .1f) + (transform.right * groundCheckDistance), -transform.up, out hitR, magnetRange, mask);

    //Calculate the average of the raycast hit normals
                Vector3 avNorm = (hitF.normal + hitB.normal + hitL.normal + hitR.normal) / 4f;
    //Store the rotation
                rotateToRoad = Quaternion.FromToRotation(transform.up, avNorm) * transform.rotation;
    }

void AlignToGround()
{
    //If there is track beneath the player
        if (magnetized)
        {
    //move rigidbody to the hover height
                rb.MovePosition(Vector3.Lerp(rb.position, transform.up * hoverHeight + magHit.point, hoverSpeed));
    //rotate to the surface normal
                rb.MoveRotation(Quaternion.Lerp(rb.rotation, rotateToRoad, alignSpeed));
        }
        else
        {
    //Fall with normal gravity and orient self
            rb.MoveRotation(Quaternion.Slerp(rb.rotation, Quaternion.LookRotation(rb.velocity.normalized, Vector3.up), 0.025f));
            rb.AddForce(Vector3.down * fakeGravity, ForceMode.Acceleration);
        }
}
2

That strange wobble is from camera, the cinemachine can follow the player in any options I think. Try adjust the parameters of the cine camera or simply try add your camera as a child of the player without the cinemachine component or parent it and just dismark the follow option.

3

(To note, I don’t have experience with the Cinemachine camera, so this perspective doesn’t take it into consideration)

On first impression, I suspect that you’re getting strange results from angular velocity as you apply your local rotation change through torque. On flat ground, you would see expected results, in that you would ease rotation toward the local right or left facing.

However, this breaks down when your pitch (X-axis rotation) changes, and the angular velocity is no longer aligned to your current flat-level axis. Your rotation from torque, especially when changing orientation rapidly in a loop, can then interfere with your expected rotation. You “correct” most of this by using Rigidbody.MoveRotation(), but that doesn’t negate the angular velocity; it just hides most of its influence.

You may want to consider re-orienting your angular velocity before applying the new steering torque, since you’re already forcing your rotation before letting torque handle the rest. I’m not in a position to verify this code at the moment, but it would be about as simple as:

// in AlignToGround()
rb.angularVelocity = rotateToRoad * rb.angularVelocity;