CGALmesh
Restricted Delaunay Triangulation (RDT)

CGALmesh is based on Delaunay refinement and uses the notion of restricted Delaunay triangulation to:

 

Definition of RDT

Point set sampled on a smooth curve (1-manifold) Delaunay triangulation and Voronoi diagram of point set The Delaunay triangulation restricted to the manifold
is the set of Delaunay faces whose dual voronoi faces
have a non-empty intersection with the manifold

 

Sampling theorem for RDT

If the sampling of the manifold is dense enough:
  • the RDT is homeomorphic to the manifold
  • the Hausdorff distance between the manifold and the RDT is small
  • normals, curvature and areas of the manifold can be estimated from the RDT.

 

Delaunay Refinement and RDT

The Delaunay refinement is tuned to satisfy the sampling condition
  • An RDT facet is considered bad if
    • either too big
    • or too far from the manifold
    • or too badly shaped
  • Each RDT facets has a surface Delaunay ball, i.e., a circumball empty of sampled points and centered on the manifold
  • Each bad RDT facet is refined by inserting the center of a surface Delaunay ball.