title: What is the difference between Point.OrientationMode ESTIMATED_SURFACE_NORMAL and Point.OrientationMode INITIALIZED_TO_IDENTITY?
body: <p>After I read the following document, the information I get is an orientation mode of the feature point is <code>ESTIMATED_SURFACE_NORMAL</code> if it is on textured surfaces, otherwise it is <code>INITIALIZED_TO_IDENTITY</code>.<br>
  But I expect the feature point to be detected because it is on textured surfaces, so I'm a bit confused about the detailed differences between the two orientation modes.  </p>
  
  <p>In addition, when we hit these feature points, are we not able to determine in advance what their orientation mode is?</p>
  
  <hr>
  
  <p><em>Attempt to estimate the normal of the surface centered around the hit test. Surface normal estimation is most likely to succeed on textured surfaces and with camera motion.</em></p>
  
  <blockquote>
    <p>public static final Point.OrientationMode <strong>ESTIMATED_SURFACE_NORMAL</strong>
    Point orientation will follow the behavior described in getHitPose().`</p>
    
    <p>public static final Point.OrientationMode <strong>INITIALIZED_TO_IDENTITY</strong>
    Point orientation is initialized to identity but may adjust slightly over time.</p>
  </blockquote>