For humanoid characters, we can use the IK approach. To do so, follow these steps:

1. Make sure to check the IK Pass option in the Animator Controller's layer properties.
2. Create a new script and call it CharacterLookAtIK.cs.
3. Create a void OnAnimatorIK(int layerIndex) function in that script. This function is called in the IK Pass after all animations are evaluated.
4. In that script, we use the SetLookAtPosition() and SetLookAtWeight() functions on the Animator component. We use a public Transform target variable to set the look at position and a public float weight variable to set the weight of the look at. We also use the Vector3.SmoothDamp() method to damp any sudden changes in the position of our target:

        targetPosition = Vector3.SmoothDamp(targetPosition, 
        target.position, ref dampVelocity, dampTime); 
        anim.SetLookAtPosition(targetPosition); 
        anim.SetLookAtWeight(weight); 

5. Save the script and assign it to the character.
6. Assign the Target game object to the Target field in the script's Inspector. Make sure to set the Weight field to 1.

7. Play the game and move the Target game object to see the result (you can do it in the Scene View).
8. To turn the look at on and off smoothly, interpolate the weight value in time using the Mathf.Lerp() function.