This was a walk thru of the tool

Supports compositing, Particle emitters and positional audio 

Tried to follow along, but Xcode beta did not include Reality Composer Pro (Yet) and when I went to download additional tools, it was not there – and Safari crashed on me. 

Uses .usda format for the project, and packages it as a Swift Package..

You can use Object capture to add items into Reality Composer Pro.

Nice to see that they support WASD for movement around the scene…gamers will feel comfortable with this navigation.

Excellent discussion on Particle Emitter creation, along with performance implications.

Grouping objects into other objects is key for authoring both audio, particle emitters and objects.

There are three audio types. Spacial, Ambient and Channel

Work with Reality Composer Pro content in Xcode session should be reviewed to see how to add this to your code.

Statistics tab is needed to understand the performance implications of your model.  Simplifying your model can help reduce triangles.

Explore materials in Reality Composer Pro should also be reviewed to understand model transitions.