# MDLMeshBuffer The general interface for managing storage of vertex and index data used in loading, processing, and rendering meshes. ``` protocol MDLMeshBuffer : NSCopying, NSObjectProtocol ``` ## Overview Model I/O creates buffers using an allocator that you specify when loading mesh data from a file with the [`MDLAsset`](/documentation/ModelIO/MDLAsset) class or generating meshes with the [`MDLMesh`](/documentation/ModelIO/MDLMesh) class. You can also create buffers using an allocator method such as [`newBuffer(with:type:)`](/documentation/ModelIO/MDLMeshBufferAllocator/newBuffer(with:type:)). The allocator you choose determines the concrete class of a mesh buffer and thus its storage mechanism—for example, the MetalKit class allocates objects, which share storage with Metal buffers for use in rendering. ## Topics ### Working with Data in a Buffer [`fill(_:offset:)`](/documentation/ModelIO/MDLMeshBuffer/fill(_:offset:)) Writes the specified data into the buffer. [`map()`](/documentation/ModelIO/MDLMeshBuffer/map()) Provides direct, read-only access to the buffer’s contents. [`length`](/documentation/ModelIO/MDLMeshBuffer/length) The data size of the buffer, in bytes. ### Inspecting a Buffer [`allocator`](/documentation/ModelIO/MDLMeshBuffer/allocator) The allocator object that created the buffer. [`zone`](/documentation/ModelIO/MDLMeshBuffer/zone) The memory pool from which the buffer was created. [`type`](/documentation/ModelIO/MDLMeshBuffer/type) The type of data contained in a buffer. ### Constants [`MDLMeshBufferType`](/documentation/ModelIO/MDLMeshBufferType) Options for the content of a mesh buffer, used by the [`type`](/documentation/ModelIO/MDLMeshBuffer/type) property and by [`MDLMeshBufferAllocator`](/documentation/ModelIO/MDLMeshBufferAllocator) methods for creating buffers. --- 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)