The SwiftUI sample lacks relevant code, leaving us unsure how to reference images or model data. Could you please offer some guidance?
Well, to some extent, you should be looking for guidance from the people who make SwiftUI. We simply provide a way to create SwiftUI interfaces from within Unity, and anything you might want to do in SwiftUI is going to be entirely separate from Unity, which includes the way that images and models are handled. Typically, in Xcode/SwiftUI, images and models are included as resources in your Xcode project. Both images and models need to be provided in a form that SwiftUI can load (notably, for models, USD), which is not how they are imported in Unity.
As a specific example, let’s say you put an image (test.png) and a model (robot_walk_idle.usdz) into Assets/StreamingAssets in your project, which will make Unity include those files directly in the Xcode build (under Data/Raw).
Then you could modify the SwiftUI to load the image like this:
Image(uiImage: .init(named: "Data/Raw/test.png")!)
Or the model like this:
RealityView { content in
let entity = try! await ModelEntity(named: "Data/Raw/robot_walk_idle.usdz")
content.add(entity)
}