Adds the point_to_dual_quaternion function that converts a point into its dual quaternion representation.

PiperOrigin-RevId: 413173797

Author: G4G

tensorflow_graphics/geometry/transformation/dual_quaternion.py

@@ -429,5 +429,35 @@ def conjugate_dual(
     return tf.concat((quaternion_real, -quaternion_dual), axis=-1)
 
 
+def point_to_dual_quaternion(
+    point: type_alias.TensorLike,
+    name: str = "dual_quaternion_conjugate") -> tf.Tensor:
+  """Converts a 3D point to its dual quaternion representation.
+
+  Args:
+    point: A TensorLike of shape `[A1, ..., An, 3]`, where the last
+      dimension represents a point.
+    name: A name for this op that defaults to "point_to_dual_quaternion".
+
+  Returns:
+    The dual quaternion representation of `point`.
+  """
+  with tf.name_scope(name):
+    point = tf.convert_to_tensor(value=point)
+
+    shape.check_static(
+        tensor=point,
+        tensor_name="point",
+        has_dim_equals=(-1, 3))
+
+    ones_vector = tf.ones_like(point)[..., 0:1]
+
+    return tf.concat(
+        (ones_vector,
+         tf.zeros_like(point),
+         ones_vector,
+         point), -1)
+
+
 # API contains all public functions and classes.
 __all__ = export_api.get_functions_and_classes()

tensorflow_graphics/geometry/transformation/tests/dual_quaternion_test.py

@@ -367,6 +367,34 @@ def test_conjugate_dual_preset(self):
     self.assertAllEqual(x_real, y_real)
     self.assertAllEqual(x_dual, -y_dual)
 
+  @parameterized.parameters(
+      ((3,),),
+      ((None, 3),),
+  )
+  def test_point_to_dual_quaternion_dual_exception_not_raised(self, *shape):
+    self.assert_exception_is_not_raised(
+        dual_quaternion.point_to_dual_quaternion, shape)
+
+  @parameterized.parameters(
+      ("must have exactly 3 dimensions", (4,)),)
+  def test_point_to_dual_quaternion_exception_raised(self, error_msg, *shape):
+    self.assert_exception_is_raised(
+        dual_quaternion.point_to_dual_quaternion,
+        error_msg, shape)
+
+  @flagsaver.flagsaver(tfg_add_asserts_to_graph=False)
+  def test_point_to_dual_quaternion_preset(self):
+    points = test_helpers.generate_preset_test_translations()
+    dual_quaternions = dual_quaternion.point_to_dual_quaternion(points)
+
+    ones_vector = tf.ones_like(points)[..., 0]
+    zeros_vector = tf.zeros_like(points)
+
+    self.assertAllEqual(dual_quaternions[..., 0], ones_vector)
+    self.assertAllEqual(dual_quaternions[..., 1:4], zeros_vector)
+    self.assertAllEqual(dual_quaternions[..., 4], ones_vector)
+    self.assertAllEqual(dual_quaternions[..., 5:8], points)
+
 
 if __name__ == "__main__":
   test_case.main()

tensorflow_graphics/geometry/transformation/tests/test_helpers.py

@@ -264,3 +264,11 @@ def generate_random_test_axis_angle_translation():
   random_angle = np.random.uniform(size=tensor_shape + [1])
   random_translation = np.random.uniform(size=tensor_shape + [3])
   return random_axis, random_angle, random_translation
+
+
+def generate_random_test_points():
+  """Generates random 3D points."""
+  tensor_dimensions = np.random.randint(3)
+  tensor_shape = np.random.randint(1, 10, size=(tensor_dimensions)).tolist()
+  random_point = np.random.uniform(size=tensor_shape + [3])
+  return random_point