RealityKit and Objective-C?

With what's currently available with the first Xcode-11-Beta, and iOS/iPadOS 13 Betas, can we write Objective-C code that uses RealityKit?


When I use Xcode 11 Beta to create an "Augemented Reality App", chosing "Objective-C" and "RealityKit", when it builds, it gives the error:

"Experience.rcproject: No Swift version specified. Set RCPROJECT_CODEGEN_SWIFT_VERSION to preferred Swift version. (in target 'ARTest1')"


Where would I add this "RCPROJECT_CODEGEN_SWIFT_VERSION"?


I removed the "Experience.rcproject" file from the build, and it will build, but then it crshes when running on deivce with:

"*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIViewController 0x107e04850> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key arView.'"


I don't see any kind of RealityKit.framework to add to the Build Phases / Link Binary With Libraries section in Xcode that might potentially resolve this.


I tried creating a "Single View App" using Objective-C and hand-adding an ARView to my main storyboard. When I control-drag it into the ViewController's .h, it adds the IBOutlet @property, but the build complains:

"ViewController.h:14:40: Unknown type name 'ARView'; did you mean 'UIView'?"


I can't find what to #include that defines ARView.


Is this a losing battle? Will it only work with Swift? If so, is Objective-C support on the roadmap, with an ETA?

Thanks!

Ed

Replies

You can find "RCPROJECT_CODEGEN_SWIFT_VERSION" in build settings, but I don't think that it'll work with objective c.