Lagrange Release v6.43.0

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