API Reference › core-geometry› Polyface › PolyfaceQuery › DihedralAngleSummary

dihedralAngleSummary MethodStatic

Compute a number summarizing the dihedral angles in the mesh.

  • A dihedral angle is the signed angle between adjacent facets' normals. This angle is positive when the cross product normalA x normalB has the same direction as facetA's traversal of the facets' shared edge.

dihedralAngleSummary(source: PolyfaceVisitor | Polyface, ignoreBoundaries: boolean = false): number

Parameter Type Description
source PolyfaceVisitor | Polyface facets.
ignoreBoundaries boolean if true ignore simple boundary edges, i.e., allow unclosed meshes. Default is false.
See isConvexByDihedralAngleCount for comments about passing true when there are multiple
connected components.
* Return 0 if all dihedral angles are zero (and ignoreBoundaries === true). The mesh is planar.
* Otherwise, return 1 if all dihedral angles are non-negative. The mesh probably encloses a convex volume and
has outward normals.
* Otherwise, return -1 if all dihedral angles are non-positive. The mesh probably encloses a convex volume and
has inward normals.
* Otherwise, return -2. Also return -2 if a non-manifold condition was detected, or a facet normal could not
be computed. A non-manifold condition is a positive-length edge adjacent to more than 2 facets or (if
ignoreBoundaries is false) adjacent to exactly one facet.

Returns - number

Defined in

Last Updated: 30 October, 2025