# renderCallbacks A container that holds the view’s render callbacks. ``` @MainActor @preconcurrency var renderCallbacks: ARView.RenderCallbacks { get set } ``` ## Discussion Render callbacks are closures RealityKit calls at predefined times. You can use render callbacks to modify the results of RealityKit’s rendering. If you assign a function or closure to any of the contained callback properties, RealityKit calls that function or closure at a predefined time. Setting the `ARView/RenderCallbacks-swift.postProcess` property, for example, causes RealityKit to call the assigned function or closure every frame, after RealityKit renders the scene, but before it displays it. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)