/// <summary>
/// Returns the unitized sum of halfedge normals in the face.
/// </summary>
/// <returns></returns>
public static Vec3d GetNormal <V, E, F>(this HeFace <V, E, F> face, Func <E, Vec3d> getNormal)
where V : HeVertex <V, E, F>
where E : Halfedge <V, E, F>
where F : HeFace <V, E, F>
{
if (face.IsDegree(3))
{
return(getNormal(face.First).Unit);
}
else
{
return(face.Halfedges.Sum(getNormal).Unit);
}
}
/// <summary>
/// Returns the unitized sum of halfedge normals in the face.
/// </summary>
/// <returns></returns>
public static Vec3d GetNormal <V, E, F>(this HeFace <V, E, F> face, Func <V, Vec3d> getPosition)
where V : HeVertex <V, E, F>
where E : Halfedge <V, E, F>
where F : HeFace <V, E, F>
{
if (face.IsDegree(3))
{
return(face.First.GetNormal(getPosition).Unit);
}
else
{
return(face.Halfedges.Sum(he => he.GetNormal(getPosition)).Unit);
}
}