Migrate tensorflow_graphics/math to Python 3.

PiperOrigin-RevId: 359327706

tensorflow_graphics/math/feature_representation.py

@@ -16,6 +16,7 @@
 from __future__ import division
 from __future__ import print_function
 
+from six.moves import range
 import tensorflow as tf
 
 from tensorflow_graphics.util import export_api

tensorflow_graphics/math/interpolation/tests/trilinear_test.py

@@ -13,8 +13,13 @@
 # limitations under the License.
 """Tests for trilinear interpolation."""
 
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
 from absl.testing import parameterized
 import numpy as np
+from six.moves import range
 import tensorflow as tf
 
 from tensorflow_graphics.geometry.representation import grid

tensorflow_graphics/math/interpolation/tests/weighted_test.py

@@ -13,8 +13,13 @@
 # limitations under the License.
 """Tests for google3.third_party.py.tensorflow_graphics.interpolation.weighted."""
 
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
 from absl.testing import parameterized
 import numpy as np
+from six.moves import range
 import tensorflow as tf
 
 from tensorflow_graphics.math.interpolation import weighted

tensorflow_graphics/math/optimizer/levenberg_marquardt.py

@@ -35,6 +35,7 @@
 from __future__ import division
 from __future__ import print_function
 
+from six.moves import zip
 import tensorflow as tf
 
 from tensorflow_graphics.util import export_api

tensorflow_graphics/math/optimizer/tests/levenberg_marquardt_test.py

@@ -13,8 +13,13 @@
 # limitations under the License.
 """Tests for the Levenberg Marquardt optimizer."""
 
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
 from absl.testing import parameterized
 import numpy as np
+from six.moves import zip
 import tensorflow as tf
 
 from tensorflow_graphics.math.optimizer import levenberg_marquardt

tensorflow_graphics/math/spherical_harmonics.py

@@ -18,6 +18,7 @@
 from __future__ import print_function
 
 import numpy as np
+from six.moves import range
 import tensorflow as tf
 
 from tensorflow_graphics.math import math_helpers