Check for AR platform support with the internal ArSystem class of Amazon Sumerian

AnchorPositioning.js

// Amazon Sumerian AR System
// -------------------------------------------------------------------
// Retrieve the ArSystem of Amazon Sumerian. Note that this is only
// available if running on a platform that supports AR.
// So, you can't really test your code on the PC.
this.arSystem = this.internalWorld.getSystem('ArSystem');
if (!this.arSystem) {
	// No AR system is found - cancel further initialization.
	// This usually happens on the computer so far. For testing,
	// you can remove the return statement and continue execution
	// to get a bit farther.
	console.log("No AR system found");
	return;
}
console.log("Initializing AR anchoring");