Unity HeadLook

HeadLook.cs

using UnityEngine;

public class HeadLook : MonoBehaviour
{
    [Header("Configs")]
    [Range(0.0f, 1.0f)]
    public float headLookWeight;

    private Animator animator;
    private Vector3 lookAtPosition;
    private Camera mainCam;

    private void Awake()
    {
        animator = GetComponent<Animator>();
        mainCam = Camera.main;
    }

    private void Update()
    {
        Vector3 camForward = mainCam.transform.forward * 10;
        // Yaw
        lookAtPosition.x = camForward.x;
        // Clamp pitch from horizon to up
        lookAtPosition.y = Mathf.Clamp(camForward.y, 0.0f, 1.0f);
        lookAtPosition.z = camForward.z;
    }

    private void OnAnimatorIK(int layerIndex)
    {
        Transform head = animator.GetBoneTransform(HumanBodyBones.Head);
        // Default weights apply to head only
        animator.SetLookAtWeight(headLookWeight);
        animator.SetLookAtPosition(head.position + lookAtPosition);
    }
}