Moving my character/camera makes environnement jerky

Question

I'm learning to make a Tilebased game with Unity and for that I use the Zelda alttp assets. I just have Tiles, a Camera and a moving Character with a rigidbody2D and a CircleCollider.

When the Camera follows the Character, the scene feels Jerky.

Info:

• The Camera uses the 2D Pixel Perfect package.
• The Character is moving via Rigidbody2D.MovePosition() in the FixedUpdate Method:

code:

void Update()
{
    float yInput;
    float xInput;

    #region yMovement
    if (Input.GetKey(keyMoveTop))
    {
        if (Input.GetKey(keyMoveBot))
        {
            yInput = 0f;
        }
        else yInput = 1f;
    }
    else if (Input.GetKey(keyMoveBot))
    {
        yInput = -1f;
    }
    else yInput = 0f;
    #endregion

    #region xMovement
    if (Input.GetKey(keyMoveLeft))
    {
        if (Input.GetKey(keyMoveRight))
        {
            xInput = 0f;
        }
        else xInput = -1f;
    }
    else if (Input.GetKey(keyMoveRight))
    {
        xInput = 1f;
    }
    else xInput = 0f;
    #endregion

    //Walking
    isWalking = Input.GetKey(keyMoveWalk);
    moveDirection = Vector2.ClampMagnitude(transform.right * xInput + transform.up * yInput, 1f);
}

private void FixedUpdate()
{
    _rb.MovePosition(_rb.position + moveDirection * (isWalking ? walkSpeed : runSpeed) * Time.fixedDeltaTime);
}

You can see the problem here: https://youtu.be/MA2zZPME5X4

Edit: Added all my movement code

Answer 1

Cameras are very sensible to anything that does not move them perfectly smoothly. The camera should be updated in an Update or LateUpdate. One way to handle cameras is to adjust variables in a FixedUpdate, and to move the camera in the (Late)Update based on the given variables. Moving the player in a FixedUpdate with the camera being parented to will cause flickering.

The reason why is because FixedUpdate does not align with the frame rate. Update and LateUpdate however do, which is why these are the ideal moments to move your camera.

Many people like to attach their cameras to the player, but I'd discourage from doing so. Cameras should have their own, controlled moving patterns unrelated to the arbitrary movements of the player, otherwise you risk all sorts of flickering issues like this including a loss of camera quality in general.