RealityKit

RealityKit is a high-level augmented reality and 3D rendering framework developed by Apple for building AR experiences on Apple devices. Designed to work in concert with ARKit, RealityKit provides a Swift API for rendering, animation, physics, and spatial audio, enabling developers to create immersive content without managing low-level rendering details.

The framework uses an entity–component system. Scenes are composed of entities, each of which can hold multiple components that define behavior and appearance. Common components include ModelComponent for 3D geometry, Material components such as SimpleMaterial and PhysicallyBasedMaterial, CollisionComponent and PhysicsBodyComponent for physics simulations, AnimationComponent for playback of animations, AudioComponent for spatial sound, and LightComponent or CameraComponent to influence lighting and perspective. RealityKit relies on USDZ assets and can also work with Reality Composer-created content (.reality) loaded into a scene. At runtime, ARView serves as the primary rendering surface, integrating ARKit's world tracking with RealityKit's scene graph to render AR scenes over the camera feed.

RealityKit emphasizes photorealistic rendering, real-time lighting, and realistic physics, enabling features such as dynamic shadows, environment lighting, and interactive animations. Developers can build scenes programmatically or compose content in Reality Composer and import it into RealityKit projects. It is intended for iOS and iPadOS apps, and is commonly used for games, product visualization, education, and interactive demonstrations that leverage augmented reality.

See also: ARKit, Reality Composer, USDZ.