title: Rotate object relative to its current rotation
body: <p>I have this script which makes a cube move around and rotate like a plane, But I want it to rotate relative to its current rotation.</p>
  <pre class="lang-cs prettyprint-override"><code> int movementSpeed = 2;
      public float rotspeed = 3f;
      public Rigidbody force;
      void FixedUpdate()
      {
          force.AddForce (transform.forward * Time.deltaTime * movementSpeed, ForceMode.VelocityChange);
  
          if (Input.GetKey(&quot;d&quot;))
          {
              force.AddTorque(0, rotspeed, 0, ForceMode.VelocityChange);
          }
          if (Input.GetKey(&quot;a&quot;))
          {
              force.AddTorque(0, rotspeed*-1, 0, ForceMode.VelocityChange);
          }
          if (Input.GetKey(&quot;w&quot;))
          {
              force.AddTorque(rotspeed, 0, 0, ForceMode.VelocityChange);
          }
          if (Input.GetKey(&quot;s&quot;))
          {
              force.AddTorque(rotspeed * -1 , 0, 0, ForceMode.VelocityChange);
          }
      }
  </code></pre>
  <p>If i were to rotate my plane upward, and then press &quot;a&quot; or &quot;d&quot; i would want to rotate it just left or right, but instead it attempts to rotate as if i were upright.</p>