4.2.1

Bug Fixes

• Fix non-terminating Delaunay meshing (and unbounded memory growth) when a
  3D point coincides with a camera center. Observations without a viewing
  direction are skipped and the ray walk is bounded.
• Fix GPU memory leak in LoMa matching by upgrading ONNX Runtime to 1.30.0.
• Fix darkened 3D point colors after track merging by treating black as
  "not yet colored" in Reconstruction::MergePoints3D.
• Fix the hash-map backend being derived from the build machine's Boost
  version, which made same-source builds ABI-incompatible and could corrupt
  memory. The backend now defaults to STD and mismatches are reported
  at configure time.
• Restore legacy bundle-adjustment behavior in the global mapper, fixing a
  regression introduced in 4.2.0. The inner L2 retriangulation refinement
  additionally keeps camera poses and intrinsics fixed, optimizing only 3D
  points, so triangulation outliers can no longer corrupt the cameras.
• Fix LO-RANSAC local optimization running below the estimator sample
  minimum.
• Fix CUDA illegal memory access in image rotate/transpose/flip kernels for
  large images by computing pitched row offsets in size_t.
• Fix PoissonRecon binary PLY corruption and crashes caused by inconsistent
  endianness initialization across translation units.
• Honor TwoViewGeometry.min_inlier_ratio consistently in the
  uncalibrated, forced-homography, and rig estimation paths.
• Clear payloads of DEGENERATE two-view geometries during verification
  and skip UNDEFINED/DEGENERATE pairs when loading the database
  cache, so rejected pairs no longer flow into the mappers.
• Prefer reference sensor poses when converting database images to rig
  frames, avoiding inconsistent shared rig poses.
• Fix dropped THROW_CHECK messages with recent glog versions and unify
  full-precision text stream configuration.
• Fix a race condition in download-cache directory creation during parallel
  downloads.
• Fix the image triangulator progress counter.
• Fix missing pycolmap method-chaining overrides and NumPy stub annotations.
• Keep at least one panorama rendering worker.
• Fix builds without OpenMP, add missing header includes, fix a member
  initialization order warning, and discard unused future return values in
  the image undistorters.