title: swift sphere combine star data
body: <p>i want to build a stargazing app. And now i already built a sphere and cover it with a star map (based on celestial coordinates).
  ( <a href="https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=3895" rel="nofollow">https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=3895</a> )</p>
  
  <p>now i have a json file which has the star catalog from YBS. (also based on celestial coordinates). 
  ( <a href="http://tdc-www.harvard.edu/catalogs/bsc5.html" rel="nofollow">http://tdc-www.harvard.edu/catalogs/bsc5.html</a> )</p>
  
  <p>i want to combine the data with star map, wishing the map to show the name of Constellation whenever my camera node turn to that place. but i don't know how to combine data and sphere. since the sphere will rotate due to user's latitude and time. The star data's coordinates also have to change. </p>
  
  <p>Does anyone has suggestions?</p>