def vertices
      vertices = Array.new(4)
      vertices[0] = base_point
      vertices[1] = base_point+u_vector
      vertices[2] = base_point+u_vector+v_vector
      vertices[3] = base_point+v_vector
      return vertices
    end
def vertices
      vertices = Array.new(4)
      vertices[0] = base_point
      vertices[1] = base_point+u_vector
      vertices[2] = base_point+u_vector+v_vector
      vertices[3] = base_point+v_vector
      return vertices
    end
[Output]
  return vertices of rectangle as Array of Vector3.