v0.2.0

[huangziwei]

This PR introduced compute_contact_stats() to skeliner.pair, which computes the following stats of the contact sites:

• Per-side (stats_A, stats_B), for each patch:

  • extent_long, extent_short (float): 2D in‑plane extents after projecting the patch’s face centroids to a best‑fit plane. Units are mesh units (e.g. nm if your mesh is in nm).
  • aspect (float): extent_long / max(extent_short, eps). Higher ⇒ more elongated; ~1 ⇒ round.
  • roundness (float): 4π·Area2D / Perimeter2D² of the 2D convex hull of projected face centroids. In [0,1] for convex shapes; 1 ⇒ perfect disk.
  • faces_count (float): number of faces in the patch on that side.
  • normal_dispersion (float): 1 − ||Σ(area·n)/Σ(area)||. 0 ⇒ uniform normals (planar/smooth); higher ⇒ more curvature/fragmentation.

• Pair-wise (stats_pair), for each patch:

  • area_mean (float): from contacts.area_mean (units from contacts.meta['unit']).
  • seed_count (float): number of original seeds mapped to this patch.
  • normal_opposition_dot (float): dot( n̄_A, n̄_B ), where n̄_* are area‑weighted mean normals per side. Range [-1,1]; ≈−1 indicates strongly opposed surfaces, ≈+1 same direction, ≈0 orthogonal.

these stats can be used in filter_contact_sites() to filter out the undesirable patches.

---

This update marked the completion of the scope of the contact sites detection. So we bump skeliner to v0.2.0, as now skeliner can do two things: skeletonize a mesh (v0.1) and find contact sites between two meshes (v0.2).