Restrict import of ops from Pointclouds

Summary: Move to a local import for calculating pointcloud normals, similar to _compute_face_areas_normals on Meshes.

Reviewed By: theschnitz

Differential Revision: D24695260

fbshipit-source-id: 9e1eb5d15017975b8c4f4175690cc3654f38d9a4

pytorch3d/ops/points_normals.py

@@ -20,7 +20,7 @@ def estimate_pointcloud_normals(
     Estimates the normals of a batch of `pointclouds`.
 
     The function uses `estimate_pointcloud_local_coord_frames` to estimate
-    the normals. Please refer to this function for more detailed information.
+    the normals. Please refer to that function for more detailed information.
 
     Args:
       **pointclouds**: Batch of 3-dimensional points of shape

pytorch3d/structures/pointclouds.py

@@ -2,7 +2,6 @@
 
 import torch
 
-from .. import ops
 from . import utils as struct_utils
 
 
@@ -890,7 +889,7 @@ class Pointclouds(object):
         them to the internal tensors `self._normals_list` and `self._normals_padded`
 
         The function uses `ops.estimate_pointcloud_local_coord_frames`
-        to estimate the normals. Please refer to this function for more
+        to estimate the normals. Please refer to that function for more
         detailed information about the implemented algorithm.
 
         Args:
@@ -908,6 +907,7 @@ class Pointclouds(object):
           [1] Tombari, Salti, Di Stefano: Unique Signatures of Histograms for
           Local Surface Description, ECCV 2010.
         """
+        from .. import ops
 
         # estimate the normals
         normals_est = ops.estimate_pointcloud_normals(