# flush() Applies all changes from the current automatic transaction. ``` class func flush() ``` ## Discussion SceneKit automatically calls this method at the end of each pass through the run loop, regardless of the run loop mode. If your app does not have a run loop, you must call this method explicitly. If the current transaction has any nested transactions that are still animating, SceneKit waits to commit the current transaction’s changes until those transactions complete. > Note: > If possible, avoid calling ``doc://com.apple.scenekit/documentation/SceneKit/SCNTransaction/flush()`` explicitly. By allowing ``doc://com.apple.scenekit/documentation/SceneKit/SCNTransaction/flush()`` to execute during the run loop, your app achieves better performance, atomic screen updates are preserved, and transactions and animations that work from transaction to transaction continue to function. --- 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)