Determines whether the reference image is valid.
- iOS 13.0+
ARKit considers certain images invalid for image tracking (for example, an image that's all white). Call this function on a reference image you create programmatically to make sure ARKit can track it, before passing it in to your session's
You only need this function when you create a reference image programmatically, because Xcode performs this validation for you when you create a reference image in an asset catalog.