# postProcess(context:) A method where you can implement postprocess effects. ``` nonisolated mutating func postProcess(context: borrowing PostProcessEffectContext) ``` ## Discussion RealityKit calls this method after rendering the main scene, but before it is drawn on the screen, ideal for performing screen-space effects or drawing overlays. When registering a post processing effect, the callback function needs to encode the modified frame buffer to the context’s [`targetColorTexture`](/documentation/RealityKit/PostProcessEffectContext/targetColorTexture), or nothing renders. An empty implementation might look like this, which copies the [`sourceColorTexture`](/documentation/RealityKit/PostProcessEffectContext/sourceColorTexture) directly to the [`targetColorTexture`](/documentation/RealityKit/PostProcessEffectContext/targetColorTexture): ```swift func postProcess(context: borrowing PostProcessEffectContext) { // Post processing with no effect. let blitEncoder = context.commandBuffer.makeBlitCommandEncoder() blitEncoder?.copy(from: context.sourceColorTexture, to: context.targetColorTexture) blitEncoder?.endEncoding() } ``` --- 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)