# updateMappings(texture:heap:operations:) Updates multiple regions within a placement sparse texture to alias specific tiles of a Metal heap. ``` func updateMappings(texture: any MTLTexture, heap: (any MTLHeap)?, operations: [MTL4UpdateSparseTextureMappingOperation]) ``` ## Parameters `texture` A placement sparse [`MTLTexture`](/documentation/Metal/MTLTexture). `heap` [`MTLHeap`](/documentation/Metal/MTLHeap) you allocate with type [`MTLHeapType.placement`](/documentation/Metal/MTLHeapType/placement). `operations` An array of [`MTL4UpdateSparseTextureMappingOperation`](/documentation/Metal/MTL4UpdateSparseTextureMappingOperation) instances to perform. ## Discussion You can provide a `nil` parameter to the `heap` argument only if when you perform unmap operations. Otherwise, you are responsible for ensuring the heap is non-nil and has a [`maxCompatiblePlacementSparsePageSize`](/documentation/Metal/MTLHeapDescriptor/maxCompatiblePlacementSparsePageSize) of at least the texture’s [`placementSparsePageSize`](/documentation/Metal/MTLTextureDescriptor/placementSparsePageSize). When performing a sparse mapping update, you are responsible for issuing a barrier against stage `MTLStageResourceState`. You can determine the sparse texture tier by calling `MTLTexture/sparseTextureTier`. --- 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)