# MDLMeshBufferMap An object that manages access to a memory buffer used for the data storage of a Model I/O mesh. ``` class MDLMeshBufferMap ``` ## Overview Typically, you do not create [`MDLMeshBufferMap`](/documentation/ModelIO/MDLMeshBufferMap) objects directly. Instead, you use classes supporting the [`MDLMeshBuffer`](/documentation/ModelIO/MDLMeshBuffer) protocol to manage mesh buffer memory shared with a rendering technology—for example, the class for rendering with Metal. A mesh buffer object vends a [`MDLMeshBufferMap`](/documentation/ModelIO/MDLMeshBufferMap) objects when you use the [`map()`](/documentation/ModelIO/MDLMeshBuffer/map()) method to gain temporary access to the shared memory. > Important: > When you use a mesh buffer’s ``doc://com.apple.modelio/documentation/ModelIO/MDLMeshBuffer/map()`` method, the buffer remains mapped for as long as that ``doc://com.apple.modelio/documentation/ModelIO/MDLMeshBufferMap`` object exists. Mapping a buffer may impose restrictions on a system. For example, a buffer in shared GPU memory may be unavailable for rendering while mapped, causing draw calls that use the buffer to fail until the corresponding ``doc://com.apple.modelio/documentation/ModelIO/MDLMeshBufferMap`` object is deallocated. ## Topics ### Creating a Buffer Map [`- initWithBytes:deallocator:`](/documentation/ModelIO/MDLMeshBufferMap/init(bytes:deallocator:)) Initializes a buffer map object to manage access to the specified memory. ### Accessing Buffer Data [`bytes`](/documentation/ModelIO/MDLMeshBufferMap/bytes) A pointer to the mutable memory managed by the buffer map. ## Relationships ### Conforms To [`Equatable`](/documentation/Swift/Equatable) [`Hashable`](/documentation/Swift/Hashable) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`CVarArg`](/documentation/Swift/CVarArg) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) ### Inherits From [`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class) --- 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)