This script drives the Extended UI prefab.
The Holoplay that this extended UI will paint to
The Unity canvas to be drawn
The camera that produces the background image underneath the UI
When true, the background of the UI will be a flat version of what Holoplay is capturing. This background will update as Holoplay Capture also updates. When set to false, the UI's background will stop following the Holoplay Capture's camera settings.