TransformBy旋转对象

   Dim L1 As New DatabaseServices.Line(P1, P3)
   
   Dim angle As Double = New DatabaseServices.Line(ppr1.Value, ppr2.Value).Angle - Math.PI / 4

   Dim vector As New Geometry.Vector3d(0, 0, 1)

   Dim Matrix3d As Geometry.Matrix3d = Geometry.Matrix3d.Rotation(angle, vector, ppr1.Value)

   L1.TransformBy(Matrix3d)