Bring back root reference in grid sensor#5300

Merged

dongruoping merged 8 commits intomainfrom

develop-grid-rootrefernece

Apr 23, 2021

Commits on Apr 20, 2021

bring back root reference
Ruo-Ping Dong
committed
docstring
Ruo-Ping Dong
committed
center the sensor around game object not root
Ruo-Ping Dong
committed
fix tests
Ruo-Ping Dong
committed

Commits on Apr 22, 2021

rename root reference to agent game object
Ruo-Ping Dong
committed
update scene
Ruo-Ping Dong
committed
also update internal names
Ruo-Ping Dong
committed
update migration guide
Ruo-Ping Dong
committed