function VertexNode(point) {
    this.point = point;
    this.prev = null;
    this.next = null;
    this.face = null; // the face that is able to see this vertex
  }
function VertexNode(point) {
    this.point = point;
    this.prev = null;
    this.next = null;
    this.face = null; 
  }
function VertexNode ( point ) { this . point = point ; this . prev = null ; this . next = null ; this . face = null ; // the face that is able to see this vertex }
A vertex as a double linked list node.
A vertex as a double linked list node .