zeux/meshoptimizer

meshoptimizer is a C/C++ library of algorithms for the data side of real-time 3D rendering: reordering and compressing vertex and index buffers, simplifying meshes, and building clusters for modern rasterization and ray tracing. It targets graphics programmers and engine/tooling developers working with glTF or custom geometry formats, not people looking for a point-and-click mesh editor. The header is C-compatible even though the implementation is C++, so it can also be reached from other languages via FFI, a Rust crate, or a JavaScript package for some algorithms documentation.

What it changes in a workflow

The library organizes its work as an ordered core pipeline: indexing (removing redundant vertices), vertex cache optimization, optional overdraw optimization, vertex fetch reordering, vertex quantization, and index filtering, with optional shadow indexing. Order matters — for example vertex fetch optimization must run on the final index buffer, and shadow indexing after the other vertex/index optimizations pipeline docs. After this, lossless vertex and index codecs are intended to be fed already-optimized and quantized data; feeding unoptimized meshes yields poor compression ratios compression docs.

Simplification is the other major path. meshopt_simplify returns a new index buffer that reuses existing vertices; variants add attribute-aware error weighting, allow collapsing across attribute seams (permissive mode), or update vertex positions in place — the latter overwrites the original vertex buffer, so it must be copied first if the original mesh is still needed simplification docs.

Clusters, mesh shaders and ray tracing

For meshlet-based pipelines, the library builds and partitions clusters for mesh shading or clustered ray tracing, and provides dedicated meshlet and point-cloud codecs plus position-exponent helpers for DXR2-style compressed encoding clusterization docs. Clustered ray tracing is documented as reducing performance for static geometry versus a traditional BLAS, with its benefit being the ability to update individual clusters for deformation or hierarchical LOD ray tracing section.

Requirements and limits

• Build with CMake or by adding only the needed src/*.cpp files; releases are also packaged for several Linux distributions, vcpkg and Conan, and a current release branch is available on GitHub installing.
• The bundled gltfpack command-line tool optimizes glTF files; the npm build is noted as less efficient and without texture compression compared with native binaries gltfpack.
• Non-experimental APIs keep source, binary and behavioral compatibility across updates, but algorithm output is not guaranteed identical; experimental APIs may change or be removed experimental APIs.
• Encoded data from older versions decodes with newer ones, and newer encodes can decode on older versions when format versions are pinned; meshlet data carries no embedded version header versioning.
• Custom allocators must throw or abort on out-of-memory — the README explicitly says malloc is not safe for this contract memory management.
• MIT licensed; the README asks for attribution in user-facing documentation license.

HotRepo's take

Daily-board observations exist for 2026-07-10 through 07-12 and 2026-10-30 (7,985 to 8,718 stars), but the sample is too sparse to call a trend; the project has existed since 2016 regardless repository.