boundary A boundary of trimmed or natural surfaces is defined by a clean contour.


clean contour A clean contour is a set of curves or surface edges, joined, ordered, eventually trimmed,
with G0, G1 or G2 continuity constraints.
curves They may be created through:
  • sketches on meshs,
  • smoothing of scans,
  • blending of curves,
  • canonic recognition (line, circle),
  • accuracy selecting.


scans They can be obtained by:
  • the identification of feature points (boundaries, sharp edges, breaks in curvature, inflection lines),
  • sketches on meshs.
segmentation This operation defines zones on the cloud of points through:
  • curvature criteria,
  • normal criteria (isoslope, outlines),
  • feature recognition (sphere, cylinder, plane, cone),
  • threshold of distance deviation from a given surface,
  • It may include scans or curves.
  • It may be automatic, manual or both.