Dependencies

• 📌 Add support for Eigen 5
• 📌 Update vcpkg baseline to move to OpenVDB 13

New Module: serialization2

• ✨ New serialization2 module for SurfaceMesh, SimpleScene, and Scene
  • Uses cista for zero-copy deserialization and zstd for optional multi-threaded compression
  • Does not require the full dependency set of lagrange::io
  • API: serialize_mesh / deserialize_mesh / save_mesh / load_mesh (and scene equivalents)
  • Suggested file extensions: .lgm (SurfaceMesh) and .lgs (Scene / SimpleScene)
  • Cross-type deserialization via allow_scene_conversion and allow_type_cast

Core Module

• ✨ Add mesh_bbox() utility to replace unsafe Eigen 5 iteration patterns
• ✨ Add compute_facet_facet_adjacency() — supports non-manifold meshes; returns a compressed CSR AdjacencyList; non-manifold edges (3+ incident facets) produce complete clique connections
• ✨ Add opt-in corner attribute support to uv_mesh_ref and uv_mesh_view
• 🐛 Avoid welding invalid values in weld_indexed_attribute

Scene and IO Modules

• 🐛 Map missing OBJ indices (normals, UVs) to invalid attribute values instead of crashing
• 🐛 Fix WASM/Emscripten test failure by forcing embedded images for binary glTF

BVH Module

• ✨ Add compute_uv_overlap for detecting overlapping triangles in UV space

Raycasting Module

• ✨ Add compute_local_feature_size

Polyddg Module

• ✨ Helmholtz-Hodge decomposition for 1-forms on polygonal meshes
  • Decomposes into exact (gradient), co-exact (divergence-free), and harmonic parts
  • VEM-stabilized inner products for consistent differential operators
  • Saddle-point solver for the co-exact part; dim(harmonic) = 2g for genus-g surfaces
• ✨ Hodge decomposition for vertex vector fields with n-rosy support

Subdivision Module

• ✨ Add adaptive tessellation based on chordal deviation: new max_chordal_deviation option, mutually exclusive with max_edge_length
• 🐛 Fix subdivide_mesh with zero subdivision levels

Texproc Module

• ✨ Precise alpha carving with threshold interpolation
• 🐛 Fix ambiguous marching squares case and add bilinear alpha sampling

Python

• 🐛 Allow extract_submesh to accept list or tensor for selected_facets
• 🐛 Fix Python submodule imports
• 🎨 Move OpenVDB initialization to the volume module

Miscellaneous

• 🐛 [polyscope] Fix registration of 4-channel vector/color attributes
• 🎨 [polyscope] Use categorical data type for integer scalar attributes
• 🐛 [volume] Add support for meshes with >4-vertex facets in voxelization

Dependencies

• 📌 Update spdlog to 1.17.0
• 📌 Update gl3w to fix link issues on Linux
• 📌 Add support for Embree 4, now the default

Python

• 🚨 Rename Lagrange Python package to adobe-lagrange to improve compatibility with internal releases while avoiding PyPI collision
  • Before: uv pip install lagrange-open
  • After: uv pip install adobe-lagrange
  • Import name unchanged (import lagrange)
  • Redirection packages ensure transitions to the latest versions
• 🐛 Fix hierarchical logging in Python

Core Module

• 🎨 Broadcast constant value attributes in map_attribute
• 🐛 Fix issues with weld_indexed_attributes
• 🐛 Fix double-flip bug in facet reorientation for orient_outward

Scene and IO Modules

• ✨ Add Scene to SimpleScene conversion functions
• 🐛 Fix node indexing bug in save_gltf when using explicit root nodes
• 🐛 Skip non-triangle primitives in load_scene_gltf, load empty placeholder mesh
• 🐛 Fix FBX load issue with duplicate attribute names
• 🐛 Account for geometry transforms and scale inherit mode in load_fbx
• 🐛 Fix image size assert in load_gltf

Remeshing Module

• ✨ New remeshing_im module wrapping Instant Meshes

Polyddg Module

• ✨ Shape operator for discrete curvature computation

BVH Module

• ✨ Add mesh-to-mesh distance evaluation
  • New bvh::compute_mesh_distances for per-vertex distance
  • Add bvh::compute_hausdorff and bvh::compute_chamfer metrics
  • Python bindings available

Raycasting Module

• ✨ New RayCaster class for SurfaceMesh
  • Construction: add_mesh(), add_instance(), add_scene()
  • Modification: update_mesh(), update_vertices(), update_transform()
  • Support visibility, intersection and occlusion filters
  • Distance queries: closest_pointN(), closest_vertexN()
  • Ray queries: castN(), occludedN()
• Refactored projection functions to support SurfaceMesh:
  • Can project either vertex positions or attributes such as colors
  • project_closest_point(), project_closest_vertex(), project_directional()
• Python bindings available

TexProc Module

• ✨ Mesh with alpha mask to SDF conversion
• 🐛 Apply regularization consistently to LHS and RHS (filtering + stitching)

Miscellaneous

• 🏗️ Chainload WindowsToolchain for vcpkg on Windows
• 🐛 Support empty inputs in mesh subdivision
• 🎨 Unify index buffer in polyscope mesh viewer example
• 🎨 Expose grid background value in Python bindings
• 🎨 Update default rendering setting for large point clouds

Dependencies

• 📌 Update Eigen to 3.4.1
• 📌 Update ufbx to v0.21.2
• 📌 Downgrade Entt to v3.15.0 due to type matching issues
• 📌 Switch pcg-cpp repo source with WinARM support
• 📌 Update OpenVDB to 13.0.0

Infrastructure

• 🐛 Numpy 2.4.0 compatibility fix
• 🏗️ New trigger to build python wheel for PRs
• 🏗️ Fix doc build failures
• 🏗️ Auto extract version from git tags

Scene and IO Modules

• 🎨 Add scene_to_meshes and simple_scene_to_meshes
• 🎨 Add option to triangulate mesh during saving
• 🎨 Allow saving scenes with invalid URI to OBJ with warnings
• 🐛 Fix target axis and units when loading FBX models
• 🐛 Load empty images when failed to load FBX textures
• 🐛 Proper attribute usage for tangent/bitangent attributes from FBX

Core Module

• 🎨 Faster per-vertex component computation (~23% faster)

BVH Module

• ✨ Add remove_interior_shells support for removing non-intersecting interior shells

TexProc Module

• 🎨 New graphical demo for texture stitching

Subdiv Module

• 🎨 Add compute_sharpness helper function

Volume Module

• 🎨 mesh_to_volume updates:
  • New Unsigned signing mode
  • Update winding number signing
  • Bug fix in quad-to-tri tessellation
• 📝 Update example demos
  • New voxelize_gui and grid_viewer examples
  • New register_grid.h utility for visualizing VDB grids with Polyscope in examples
  • Rename voxelize_mesh -> voxelize_cli and support additional input/output files
• 🎨 Add NanoVDB support in demos/Python bindings
• ✨ New Grid class wrapping OpenVDB grids (CPU only)
  • .to_mesh() and .from_mesh() for converting between mesh <-> SDF grid (float or double)
  • .save(), .to_buffer() and .load() for serialization (supports NanoVDB and compression)
  • Grid properties: .bbox_index, .bbox_world, .num_active_voxels
  • .world_to_index() and .index_to_world() to apply coordinate transforms
  • .sample_trilinear_*() to sample points in parallel
  • .resample(), .densify(), .redistance() and .offset_in_place() utility methods

Minor release to fix Python documentation issues.

Dependencies

• 📌 Updated oneTBB to 2022.3.0 and oneMKL to 2025.3.0
• 📌 Updated spdlog from 1.15.1 to 1.16.0
• 📌 Updated fmt from 11.1.4 to 12.0.0
• 📌 Updated EnTT from 3.13.2 to 3.16.0

Core Module

• ✨Added compute_uv_area function
• 🎨 compute_edge_is_manifold can now compute a per-edge attribute indicating manifoldness
• 🎨 Added support for inverting normal/bitangent attributes when flipping facets
  • orient_outward will now flip normal/bitangent attributes
• 🐛 Fixed infinite loop issue in earcut triangulation

Python Bindings

• 🐍 Added python bindings for:
  • compute_edge_is_oriented
  • compute_vertex_is_manifold
  • compute_edge_is_manifold
• 🐍 Added python bindings for SurfaceMesh::foreach_* functions
• 🎨 Improved meshstat.py: added orientation check, non-manifold count, facet stats

Primitive Module

• 🎨 Now open source!

IO Module

• 🏗️ Silenced IO warnings in unit tests
• 🎨 Added quiet option for saving meshes

Texproc Module

• 🎨 Added option to regularize the stiffness matrix in texture filtering and stitching
• 🎨 Added option to clamp output values in texture filtering / stitching / compositing
• 🎨🐍 Exposed options to C++ examples and python bindings
• 🐛 Fixed non-deterministic __randomize option in texture stitching
• 🏗️ Made unit tests single-threaded to ensure reproducibility, and changed to stricter tolerances

Polyscope Module

• ✨ New dedicated module to facilitate interop with Polyscope
  • Register explicit structure:
    • register_edge_network
    • register_mesh
    • register_point_cloud
  • Infer structure type from mesh connectivity:
    • register_structure
  • Create or update Polyscope attribute based on Lagrange's:
    • register_attribute

Infrastructure

• 🏗️ Compilation fixes for Xcode 26
• 🏗️ Fix CMake sanitizer setup for MSVC
• 📌 Update earcut.hpp dependency to f36ced7
• 📌 Update cpptrace to 1.0.4
• 📌 🐛 Update PoissonRecon dependency to fix a memory allocation bug

Core Module

• 🎨 Add overload to SurfaceMesh::delete_attribute to accept id as input

IO Module

• 🐛 Throw error when saving float/double texture to glTF file
• 📖 Add explicit warning when loading glTF without explicit stitching behavior
• 🎨 Add new LoadOptions::quiet to silence IO related log messages
• 🎨 Update STL mesh load to not stitch vertices by default for consistency with other formats

Solver Module

• ✨ Add support for Spectra-based sparse eigenvalue solver
  • [generalized_]selfadjoint_eigen_[largest|smallest]() in C++
  • lagrange.solver.eigsh() in Python (follows a similar API to scipy.linalg.eigsh())

Texproc Module

• 🐛 Fix out-of-bound access in rasterization code
• 🐛 Add checks to ensure number of channels consistency
• 🐍 Update texture_from_multiview.py to accept list of render images + ensure output uses .exr
• 🐛 Fix vertical flip in geodesic_dilation code introduced in v6.38.0
• 🐛 Fix image transpose issue in Python bindings
• 🐍 Add geodesic_dilation.py demo

Geodesic Module

• ✨ New geodesic module to compute single-source and point-to-point geodesic distance
  • Added GeodesicEngine[...] class for repeated computation
  • Choice of algorithm between DGPC, MMP and Heat
  • Two methods available: single_source_geodesic() and point_to_point_geodesic()

Polyddg Module

✨ New polyddg module that implements most of the operators from this paper:

De Goes, F., Butts, A., & Desbrun, M. (2020).
Discrete differential operators on polygonal meshes.
ACM Transactions on Graphics (TOG), 39(4), 110-1.

Documentation

• 📖 Docstring updates for scene module
• 📖 Update voxelize_mesh example code to read/write .vdb files
• 📖 Fixed typos and grammar in comments with Copilot

Python Bindings

• 📌 Updated scikit-build core to 0.11.6
• 📌 Updated sphinx and autoapi
• 🏗️ Set upper-bound to Python <3.14 due to nanobind uncertainty
• 📖 Fixed generated Sphinx documentation due to refactored stub files

Full Changelog: v6.38.0...v6.39.0

Infrastructure

• 🏗️ New CMake option LAGRANGE_PROPAGATE_WARNINGS
• 📌 Update Catch2 to v3.10.0
• 📌 Update WindingNumber to v0.3.15
• 🏗 Enable \Z7 flag in MetaBuild for debug build

Core module

• 🏗️ Replace M_PI with lagrange::internal::pi
• ✨ Add compute_facet_circumcenter
• ✨ Add compute_facet_vector_area
• 🐍 Add SurfaceMesh.edges in python binding
• 🎨 Update point_triangle_squared_distance and point_segment_squared_distance to be dimension independent

IO module

• 🐛 Bug fix in directory creation when saving obj file

Texproc module

• 🐛 Add check for flipped UV triangles
• 🗑️ Cleanup geodesic dilation code

BVH module

• 🎨 Refactor AABB as a stand-alone class
• 🎨 Add support for TriangleAABBTree
• 🎨 Update EdgeAABBTree
• 🎨 Add python binding for TriangeAABBTree and EdgeAABBTree

Documentation and other updates

• 📌 Update Doxygen and CSS version
• 📌 Update website dependency
• 💄 Update code format for the entire repo
• 📖 Improve texproc documentation
• 🏗️ Add explicit ref to Doxygen comments
• 🏗️ Remove doxygen autolink
• 📖 Update python doc strings
• 🐛 Fix python stub generation

Infrastructure

• 🏗️Improved DLL copies with CMake. This fixes some Jenkins failure cases.
• 🏗️Improved code-coverage.cmake. Prevents overwriting job pools configurations for downstream projects, improves cross-platform support, and adds configuration options.
• 🏗️Run patchelf on downloaded MKL to prevent linking issues.
• 🐛Fixed ODR issues.
• 📌Updated MshIO to v0.1.0
• 📌Updated miniz from 2.2.0 to 3.0.2

Core Module

• 🎨Improved stability in remove_duplicate_vertices(), it now keeps vertices order if possible

Python Bindings

• 🏗️Moved all nanobind includes to a single file <lagrange/python/binding.h> to avoid potential ODR violations.
• 📖Updated pyproject.toml to have urls.documentation and urls.repository
• 📌Updated nanobind to v2.9.2. This adds support for in-place updates to dicts, lists, etc., such as my_dict["key"] += 1

Scene Module

• 🐛To fix a mutable element issue in python bindings, changed Scene types from std::vector<T> to lagrange::SafeVector<T> which is an alias for
  • std::vector<std::shared_ptr<T>> when compiled for python bindings
  • std::vector<T> otherwise, unchanged from before
• 🎨Updated Scene::far_plane to be optional
• ✨Added camera matrix utilities in <lagrange/scene/scene_utils.h>
  • Eigen::Affine3f camera_view_transform(const Camera& camera, const Eigen::Affine3f& world_from_local)
  • Eigen::Projective3f camera_projection_transform(const Camera& camera)

Solver Module

• ✨New solver module! It manages dependencies across platforms and provides aliases for solver wrappers. Currently contains <lagrange/solver/DirectSolver.h>

Texture Signal Processing

• ✨New texproc module! It provides texture-space operations such as filtering (smoothing, sharpening), stitching, compositing.

Infrastructure

• 🏗️ Add export macros for filtering module
• 🏗️ Minor CMake cleanups
• 📌 Update cpptrace to 1.0.3 and removed StackWalker

Core Module

• 🎨 New is_closed() function for SurfaceMesh
• 🎨 Support degenerate polygons in compute_weighted_corner_normal()
• 🎨 Support for indices shared across vertices in weld_indexed_attribute()
• 🐛 Fix out-of-bound bug in split_edges() for 2D meshes

IO Module

• 🎨 Added save_simple_scene_obj()
  • Supports multiple nodes and instances
• 🎨 Added save_scene_obj()
  • Supports uvs, materials, and multiple nodes and instances
• 🏗️ Changed io tests to write to a designated output directory (build/tmp)
• 📖 Improved Python documentation in io and scene
• 🎨 New scene_convert example

BVH Module

• ✨ New weld_vertices() function for SurfaceMesh

Volume Module

• 🎨 Added sample_vertex_normal() to sample normals from VDB grid

Infrastructure

• 🏗️ Add existence check in get_data_path and get_data_folder for loading unit test assets

Core and IO modules

• 🎨 Indexed attribute support for saving in MSH format
• 🐛 Throw exception for unsupported format in load_scene and load_simple_scene
• 🐛 Bug fix in split_triangle
• 🐛 Bug fix in map_attribute
• 🎨 Add centroid-fan support in triangulate_polygonal_facets
• ✨ New split_facets_by_material function

Filtering module

• 🎨 Support smoothing of multi-channel attribute