DirectXMesh geometry processing library

https://go.microsoft.com/fwlink/?LinkID=324981

Copyright (c) Microsoft Corporation.

May 7, 2026

This package contains DirectXMesh, a shared source library for performing various geometry content processing operations including generating normals and tangent frames, triangle adjacency computations, vertex cache optimization, and meshlet generation.

This code is designed to build with Visual Studio 2022, Visual Studio 2026, or clang for Windows v12 or later, or MinGW. Use of the Windows 11 SDK (22000) or later is required for Visual Studio. It can also be built for Windows Subsystem for Linux using GCC 12 or later.

These components are designed to work without requiring any content from the legacy DirectX SDK. For details, see Where is the DirectX SDK?.

Directory Layout

• DirectXMesh\

  • This contains the DirectXMesh library.

The majority of the header files here are intended for implementation the library only (DirectXMeshP.h, scoped.h, etc.). Only DirectXMesh.h and DirectXMesh.inl are meant as a 'public' headers for the library.

• Utilities\

  • This contains helper code related to mesh processing that is not general enough to be part of the DirectXMesh library.
    • WaveFrontReader.h: Contains a simple C++ class for reading mesh data from a WaveFront OBJ file.
    • FlexibleVertexFormat.h: Contains helpers for working with Direct3D 9 style "FVF" codes.

• Meshconvert\

  • This DirectXMesh sample is an implementation of the meshconvert command-line texture utility from the legacy DirectX SDK utilizing DirectXMesh rather than D3DX.

This tool does not support legacy .X files, but can export CMO, SDKMESH, and VBO files.

• build\

  • Contains miscellaneous build files and scripts.

• skills\

  • Contains published CoPilot skills for use by developers.

Documentation

Documentation is available on the GitHub wiki.

CoPilot Usage

For CoPilot CLI assistance with using DirectXMesh, try:

winget install GitHub.Copilot
winget install GitHub.cli
gh skill install microsoft/directxmesh
copilot
/skills list

Notices

All content and source code for this package are subject to the terms of the MIT License.

For the latest version of DirectXMesh, bug reports, etc. please visit the project site on GitHub.

Release Notes

FOR SECURITY ADVISORIES, see GitHub.

For a full change history, see CHANGELOG.md.

• clang-format use for this project must match the version use by GitHub Super-Linter to pass the validation. VS 2022 and VS 2026 come with different versions, so to match use:

winget install --id=LLVM.LLVM --version 21.1.2
powershell -File build/Format.ps1 -LLVM

• The directxmesh_desktop_win10 and directxmesh_uwp NuGet packages are deprecated. The best way to integrate the latest DirectXMesh into your C++ project is using vcpkg.

• The CMake projects require 3.21 or later.

• Starting with the May 2026 release, the functions OptimizeFaces, OptimizeFacesLRU, OptimizeFacesEx, and OptimizeFacesLRUEx now take an nVerts parameter in order to validate the input indices. This is a breaking change.

hr = OptimizeFaces(indices, nFaces, adjacency, faceRemap, vertexCache, restart);

Must be updated to:

hr = OptimizeFaces(indices, nFaces, nVerts, adjacency, faceRemap, vertexCache, restart);

• Starting with the March 2025 release, Windows 7 and Windows 8.0 support has been retired.

• Starting with the June 2020 release, this library makes use of typed enum bitmask flags per the recommendation of the C++ Standard section 17.5.2.1.3 Bitmask types. This is consistent with Direct3D 12's use of the DEFINE_ENUM_FLAG_OPERATORS macro. This may have breaking change impacts to client code:

  • You cannot pass the 0 literal as your flags value. Instead you must make use of the appropriate default enum value: CNORM_DEFAULT, VALIDATE_DEFAULT, or MESHLET_DEFAULT.

  • Use the enum type instead of DWORD if building up flags values locally with bitmask operations. For example, CNORM_FLAGS flags = CNORM_DEFAULT; if (...) flags |= CNORM_WIND_CW;

• The UWP projects and the Win10 classic desktop project include configurations for the ARM64 platform. Building these requires installing the ARM64 toolset.

• When using clang/LLVM for the ARM64/AArch64 platform, the Windows 11 SDK (22000) or later is required.

• As of the October 2024 release, the command-line tool also supports GNU-style long options using --. All existing switches continue to function, but some of the - options are now deprecated per this table:

Support

For questions, consider using Stack Overflow with the directxtk tag, or the DirectX Discord Server in the dx12-developers or dx9-dx11-developers channel.

For bug reports and feature requests, please use GitHub issues for this project.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

Tests for new features should also be submitted as a PR to the Test Suite repository.

Code of Conduct

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.

Credits

The DirectXMesh library is the work of Chuck Walbourn, with contributions from Dr. Hugues Hoppe, Alex Nankervis, James Stanard, Craig Peeper, and the numerous other Microsoft engineers who developed the D3DX utility library over the years.

Thanks to Matt Hurliman for his contribution of the meshlet generation functions.

Thanks to Adrian Stone (Game Angst) for the public domain implementation of Tom Forsyth's linear-speed vertex cache optimization, and thanks to Tom Forsyth for his contribution.

Thanks to Andrew Farrier, Jon Martin, and Scott Matloff for their help with code reviews.

Thanks to Shawn Hargreaves and Nada Ouf for their continued support for this library.