Lagrange Release v6.49.0

Dependencies

• 📌 Update earcut to f25bc76 for Delaunay refinement.
• 📌 Update scikit-build-core to 1.1.0.

Build & CI

• 🐛 Repair nightly sanitizer presets: Fix test environments and GPU-driver leak handling
• 🏗️ Halve open-source Unix CI to 9 jobs; improve compiler caching: Retain ASan / TSan coverage; bound heavy dependency compilation.
• 🏗️ Keep Python CI on 3.13; omit pyexr tooling on 3.14.

Python Bindings

• 🐍 Expose chain_edges for directed and undirected edge chaining.
  • Required keyword-only directed flag selects the chaining mode.
  • Returns loops / chains; supports edge-index output and explicit loop closure.
• 🐍 Expose extension build mode through lagrange._ndebug: Reports whether the extension was compiled with NDEBUG.

Core Module

• 🎨 Add a Delaunay polygon-triangulation scheme: Lawson edge flips remove near-collinear earcut slivers; C++, Python, and JS/WASM.
• 🐛 Fix std::format formatter detection for join views: Remove libc++ include-order dependence and support its formattability probes.

Remeshing Module

• 🐛 Fix intermittent deadlock in remeshing_im: Synchronize optimizer requests to prevent lost condition-variable wakeups.

Occlusion Culling

• 🔥 Redesign remove_occluded around graded visibility measures.
  • Area-aware AO sampling and confidence-based early ray retirement.
  • Re-filter at a new threshold without retracing rays.
  • Breaking API changes for all facets functions; legacy instance functions deprecated.

Geodesic Module

• ✨ Add flip-to-geodesic engine GeodesicEngineFlip. (#1898)
  • Approximate point-to-point distances and paths via edge flips.
  • C++ and Python; optional geodesic::geometrycentral component.
  • Configurable path shortening and Algorithm::FLIP.

IO & Mesh Repair

• 🐛 Fix point-cloud loading with vertex stitching and attributes: Avoid assertion failures with stitch_vertices=true.
• 🐛 Avoid sliver triangles when resolving T-junctions: Use split_triangle for triangle meshes; retain polygonal-input fallback.
• ✨ Add PCD point-cloud read / write support.