APR 26 2018: Fixed gl_instanceID as mat4[] array index related Adueno 330 GPU bug
Mar 22 2018: Fine tuned some algorithms
Jan 02 2018: Fixed minor bugs. Added light source visual.
Dec 29 2017: Minor bug fix.
Nov 9 2017: Minor bug fix.
Oct 15 2017: Minor bug fix.
July 16 2017: Minor bug fix.
June 21 2017: Complete re-write from scratch. Will NOT play with previous versions. Fighter jet model added. More responsive Bluetooth connection.