public static double OpeningAngleD(NGonsCore.geometry3Sharp.mesh.DMesh3 mesh, int eid)
{
Index2i et = mesh.GetEdgeT(eid);
if (et[1] == NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID)
{
return(double.MaxValue); // boundary edge!!
}
Vector3D n0 = mesh.GetTriNormal(et[0]);
Vector3D n1 = mesh.GetTriNormal(et[1]);
return(Vector3D.AngleD(n0, n1));
}