References wblut.geom.WB_Vector.addSelf(), wblut.hemesh.HE_Face.getHalfedge(), wblut.hemesh.HE_Halfedge.getNextInFace(), wblut.hemesh.HE_Halfedge.getVertex(), wblut.geom.WB_Vector.normalizeSelf(), wblut.hemesh.HE_Vertex.xd(), wblut.hemesh.HE_Vertex.yd(), and wblut.hemesh.HE_Vertex.zd().