CamRotor

using UnityEngine;

//Rotates camera with mouse while pressing the navigation key, or with pressing the middle mouse button
public class CamRotor : MonoBehaviour
{   
	public KeyCode navigationKey;
	public bool invertAxis = false;
	public float mouseSensitivity = 100f;
		
	private void LateUpdate()
	{
        	if(Input.GetKey(navigationKey) || Input.GetMouseButton(2))
            		RotateView();
	}
		
	private Vector3 camEulers;
	private Vector2 lastMouseAxis = Vector2.zero;
	private Vector3 mouseAxis;
	private Vector2 offset;
    	public void RotateView()
	{
		mouseAxis = new Vector3(Input.mousePosition.x - lastMouseAxis.x, Input.mousePosition.y - lastMouseAxis.y, Input.GetAxis("Mouse ScrollWheel"));

		// GetAxis() does not work with TeamViewer
		// TeamViewer provides virtual input but Unity expects hardware input
		// I have no idea what this means, I've read this on Unity forums, but this is the workaround:
		offset = (Vector2)mouseAxis; //teamviewer version
		//offset = new Vector2(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y")); //non-teamviewer version

		if(invertAxis)
		    offset *= -1f;

		camEulers.x += offset.y * mouseSensitivity * Time.deltaTime;
		camEulers.y -= offset.x * mouseSensitivity * Time.deltaTime;

		Camera.main.transform.localEulerAngles = camEulers;
	}
}