public void TestFindContactsOnPlane()
        {
            Areas.Plane3 plane = new Areas.Plane3(
                new Vector3(15.0f, 15.0f, 15.0f),
                -Vector3.Backward
                );

            LineContacts contacts = new Line3(
                new Vector3(15.0f, 15.0f, 0.0f), Vector3.Backward
                ).FindContacts(plane);

            Assert.AreEqual(
                15.0f, contacts.EntryTime,
                "Direct orthogonal contact to plane detected"
                );

            contacts = new Line3(
                new Vector3(15.0f, 15.0f, 30.0f), -Vector3.Backward
                ).FindContacts(plane);
            Assert.AreEqual(
                15.0f, contacts.EntryTime,
                "Direct orthogonal contact to plane from backside detected"
                );
        }
    public void TestFindContactsOnPlane() {
      Areas.Plane3 plane = new Areas.Plane3(
        new Vector3(15.0f, 15.0f, 15.0f),
        -Vector3.Backward
      );

      LineContacts contacts = new Segment3(
        new Vector3(15.0f, 15.0f, 0.0f), new Vector3(15.0f, 15.0f, 30.0f)
      ).FindContacts(plane);
      Assert.AreEqual(
        0.5f, contacts.EntryTime,
        "Direct orthogonal contact to plane detected"
      );

      contacts = new Segment3(
        new Vector3(15.0f, 15.0f, 30.0f), new Vector3(15.0f, 15.0f, 0.0f)
      ).FindContacts(plane);
      Assert.AreEqual(
        0.5f, contacts.EntryTime,
        "Direct orthogonal contact to plane from backside detected"
      );

    }