unity 3d mouselook script help, weird issue

Question

I'm coming back to Unity after a year or two of busy college and I'm having to relearn everything I've forgotten. One thing I cant seem to get right is this basic mouselook script I wrote. Here is the code:

    float x;
    float y;
    public float sensitivity = 75.0f;
    public float maxVerticalAngle = 75.0f;
    public Rigidbody Character;

    void Awake()
    {
        Vector3 euler = transform.rotation.eulerAngles;
        x = euler.x;
        y = euler.y;
    }

    // Update is called once per frame
    void Update()
    {
        x += Input.GetAxis("Mouse Y") * (sensitivity * Time.deltaTime);
        y += Input.GetAxis("Mouse X") * (sensitivity * Time.deltaTime);
        x = Mathf.Clamp(x, -maxVerticalAngle, maxVerticalAngle);

        //apply this just to the camera and it works
        transform.rotation = Quaternion.Euler(-x, y, 0.0f);

        //apply x changes to camera and y changes to parent rigidbody capsule and it no longer works correctly
        transform.rotation = Quaternion.Euler(-x, 0.0f, 0.0f);
        Character.transform.rotation = Quaternion.Euler(0.0f,y,0.0f);
    }

Okay, now at the end is where my problem occurs. Let me explain a little: if I apply the quaternion with both x and y changes to the rotation then it works smoothly and the camera rotates on both axes. If, however, I apply the change in x to the camera to allow looking up and down, and I apply the change in y to the rigidbody capsule I have as a parent to the camera the script is attached to then I get a weird problem. The camera rotates up and down smoothly, but the capsule twitches and only rotates a few degrees. If, however, I comment out the line where I apply changes to the camera rotation then the parent capsule rotates normally now.

TL;DR Camera is child to a capsule. When applying rotational changes to the camera and rigidbody one line after the other, the camera rotates fine, but the rigidbody does not. If I comment out the camera's rotation changes then the rigidbody rotates fine again.

I think the problem may be that I'm rotating a parent object to the camera and I'm using mouse movement to rotate the rigidbody. I'm unsure though. Please help.

If you want to recreate what I've done, then child a camera to a capsule and apply the script. Add the capsule to the rigidbody in the script and comment out this:

//apply this just to the camera and it works
transform.rotation = Quaternion.Euler(-x, y, 0.0f);

Edit: Thank you for the help. If you need more info, then please ask!

Answer 1

If you want to rotate the camera up & down relative to its rigidbody parent then set its localRotation property instead of rotation.

By setting the rotation field directly to an orientation with no yaw, you're telling Unity you want it to make a compensating rotation that undoes the parent's yaw so the camera can keep looking toward the world forward direction. Since you do this before applying more yaw to the parent, you still see one frame's worth of yaw after this compensation is applied, leading to the stuttery appearance of only rotating a few degrees.