title: Translate Unity units of measurement?
body: <p>In Unity one can use Raycasting to calculate various measurements. Examples such as diameter, thickness of a wall, and width. One way to do this is by capturing a users mouse click on an object and using RaycastHits to capture the location of the mouse click on the object and than casting additional rays depending on the measurement desired.</p>
  
  <p>Seen below:
  Thickness of the walls clicked is .0098, .0096, and .0072. Width is .0615, .0611, and .060. Diameter is .0475.</p>
  
  <p>Though these measurements are (believed to be)  executed and calculated correctly it's unclear how the results translate to real world units of measurement.</p>
  
  <p>This is best demonstrated and shown in the fourth image. Checking the same diameter in other CAD programs, such as NX, the diameter is 0.4210" or inches. Thickness and width were calculated as well at .075244" and .252872" respectively.</p>
  
  <p>So than, <strong>how do the results in Unity</strong>, (results produced using Vector3.Distance to calculate the distance between two points) <strong>translate to real world units of measurement</strong>?</p>
  
  <p>Googling the subject yields a common answer: Unity's measurements are "game units" and can be used however desired. While I grasp this, I don't understand how to accomplish the translation of "game units", or whatever Unity's units of measurement truly are, to the measurement results I can see in CAD programs.</p>
  
  <p>Results (CAD x Unity):
  Thickness: .075244" x .0098, .0096, and .0072. 
  Width: .252872" x .0615, .0611, and .060. 
  Diameter: 0.4210" x .0475</p>
  
  <p>(note1: model scales are identical in Unity and external CAD program.)</p>
  
  <p>(note2: the slight variation in thickness and width results from Unity measurements coming at angles where the CAD program is measuring distance between the two planes, i.e. .009x and .06x.)</p>
  
  <p>(note3: ignore the incorrect labeling of Width in the second visual as 'Thickness' and the inch labeling in all of the Unity visuals, ", as both incorrect).</p>
  
  <p><a href="https://i.stack.imgur.com/N1CMK.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/N1CMK.gif" alt="thickness"></a>
  <a href="https://i.stack.imgur.com/vSGtV.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vSGtV.gif" alt="width"></a>
  <a href="https://i.stack.imgur.com/sd68C.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sd68C.gif" alt="diameter-unity"></a>
  <a href="https://i.stack.imgur.com/7MM8S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7MM8S.png" alt="diameter_cadprgm"></a></p>