# physicalSize(layer:) Returns the dimensions, in pixels, of the area in the render target affected by the rasterization rate map. ``` func physicalSize(layer layerIndex: Int) -> MTLSize ``` ## Parameters `layerIndex` The index of the layer. ## Return Value The dimensions, in pixels, of the area in the render target affected by the rasterization rate map. ## Discussion Your render targets should be at least as large as the physical size returned by this method. Each layer may have different rasterization rates and therefore different physical size requirements. --- 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)