ARKit-Example-by-Apple | Placing objects This example can be downloaded from applecom | Augmented Reality library

Help users recognize when your app is ready for real-world interactions. Tracking the real-world environment involves complex algorithms whose timeliness and accuracy are affected by real-world conditions. The FocusSquare class in this example project draws a square outline in the AR view, giving the user hints about the status of ARKit world tracking. The square changes size to reflect estimated scene depth, and switches between open and closed states with a "lock" animation to indicate whether ARKit has detected a plane suitable for placing an object. Use the session(_:cameraDidChangeTrackingState:) delegate method to detect changes in tracking quality, and present feedback to the user when low-quality conditions are correctable (for example, by telling the user to move to an environment with better lighting). Use specific terms a user is likely to recognize. For example, if you give textual feedback for plane detection, a user not familiar with technical definitions might mistake the word "plane" as referring to aircraft. Fall back gracefully if tracking fails, and allow the user to reset tracking if their experience isn't working as expected. See the restartExperience button and method in this example's ViewController class. The use3DOFTrackingFallback variable controls whether to switch to a lower-fidelity session configuration when tracking quality is poor. Help users understand the relationship of your app's virtual content to the real world. Use visual cues in your UI that react to changes in camera position relative to virtual content. The focus square disappears after the user places an object in the scene, and reappears when the user points the camera away from the object. The Plane class in this example handles visualization of real-world planes detected by ARKit. Its createOcclusionNode and updateOcclusionNode methods create invisible geometry that realistically obscures virtual content.