some pointcloud typing

Summary: Make clear that features_padded() etc can return None

Reviewed By: patricklabatut

Differential Revision: D31795088

fbshipit-source-id: 7b0bbb6f3b7ad7f7b6e6a727129537af1d1873af

pytorch3d/structures/pointclouds.py

@@ -5,7 +5,7 @@
 # LICENSE file in the root directory of this source tree.
 
 from itertools import zip_longest
-from typing import Sequence, Union
+from typing import List, Optional, Sequence, Tuple, Union
 
 import numpy as np
 import torch
@@ -240,7 +240,9 @@ def __init__(self, points, normals=None, features=None) -> None:
         if features_C is not None:
             self._C = features_C
 
-    def _parse_auxiliary_input(self, aux_input):
+    def _parse_auxiliary_input(
+        self, aux_input
+    ) -> Tuple[Optional[List[torch.Tensor]], Optional[torch.Tensor], Optional[int]]:
         """
         Interpret the auxiliary inputs (normals, features) given to __init__.
 
@@ -323,24 +325,26 @@ def __getitem__(self, index) -> "Pointclouds":
             Pointclouds object with selected clouds. The tensors are not cloned.
         """
         normals, features = None, None
+        normals_list = self.normals_list()
+        features_list = self.features_list()
         if isinstance(index, int):
             points = [self.points_list()[index]]
-            if self.normals_list() is not None:
-                normals = [self.normals_list()[index]]
-            if self.features_list() is not None:
-                features = [self.features_list()[index]]
+            if normals_list is not None:
+                normals = [normals_list[index]]
+            if features_list is not None:
+                features = [features_list[index]]
         elif isinstance(index, slice):
             points = self.points_list()[index]
-            if self.normals_list() is not None:
-                normals = self.normals_list()[index]
-            if self.features_list() is not None:
-                features = self.features_list()[index]
+            if normals_list is not None:
+                normals = normals_list[index]
+            if features_list is not None:
+                features = features_list[index]
         elif isinstance(index, list):
             points = [self.points_list()[i] for i in index]
-            if self.normals_list() is not None:
-                normals = [self.normals_list()[i] for i in index]
-            if self.features_list() is not None:
-                features = [self.features_list()[i] for i in index]
+            if normals_list is not None:
+                normals = [normals_list[i] for i in index]
+            if features_list is not None:
+                features = [features_list[i] for i in index]
         elif isinstance(index, torch.Tensor):
             if index.dim() != 1 or index.dtype.is_floating_point:
                 raise IndexError(index)
@@ -351,10 +355,10 @@ def __getitem__(self, index) -> "Pointclouds":
                 index = index.squeeze(1) if index.numel() > 0 else index
                 index = index.tolist()
             points = [self.points_list()[i] for i in index]
-            if self.normals_list() is not None:
-                normals = [self.normals_list()[i] for i in index]
-            if self.features_list() is not None:
-                features = [self.features_list()[i] for i in index]
+            if normals_list is not None:
+                normals = [normals_list[i] for i in index]
+            if features_list is not None:
+                features = [features_list[i] for i in index]
         else:
             raise IndexError(index)
 
@@ -369,7 +373,7 @@ def isempty(self) -> bool:
         """
         return self._N == 0 or self.valid.eq(False).all()
 
-    def points_list(self):
+    def points_list(self) -> List[torch.Tensor]:
         """
         Get the list representation of the points.
 
@@ -388,9 +392,10 @@ def points_list(self):
             self._points_list = points_list
         return self._points_list
 
-    def normals_list(self):
+    def normals_list(self) -> Optional[List[torch.Tensor]]:
         """
-        Get the list representation of the normals.
+        Get the list representation of the normals,
+        or None if there are no normals.
 
         Returns:
             list of tensors of normals of shape (P_n, 3).
@@ -404,9 +409,10 @@ def normals_list(self):
             )
         return self._normals_list
 
-    def features_list(self):
+    def features_list(self) -> Optional[List[torch.Tensor]]:
         """
-        Get the list representation of the features.
+        Get the list representation of the features,
+        or None if there are no features.
 
         Returns:
             list of tensors of features of shape (P_n, C).
@@ -420,7 +426,7 @@ def features_list(self):
             )
         return self._features_list
 
-    def points_packed(self):
+    def points_packed(self) -> torch.Tensor:
         """
         Get the packed representation of the points.
 
@@ -430,22 +436,24 @@ def points_packed(self):
         self._compute_packed()
         return self._points_packed
 
-    def normals_packed(self):
+    def normals_packed(self) -> Optional[torch.Tensor]:
         """
         Get the packed representation of the normals.
 
         Returns:
-            tensor of normals of shape (sum(P_n), 3).
+            tensor of normals of shape (sum(P_n), 3),
+            or None if there are no normals.
         """
         self._compute_packed()
         return self._normals_packed
 
-    def features_packed(self):
+    def features_packed(self) -> Optional[torch.Tensor]:
         """
         Get the packed representation of the features.
 
         Returns:
-            tensor of features of shape (sum(P_n), C).
+            tensor of features of shape (sum(P_n), C),
+            or None if there are no features
         """
         self._compute_packed()
         return self._features_packed
@@ -483,7 +491,7 @@ def num_points_per_cloud(self):
         """
         return self._num_points_per_cloud
 
-    def points_padded(self):
+    def points_padded(self) -> torch.Tensor:
         """
         Get the padded representation of the points.
 
@@ -493,19 +501,21 @@ def points_padded(self):
         self._compute_padded()
         return self._points_padded
 
-    def normals_padded(self):
+    def normals_padded(self) -> Optional[torch.Tensor]:
         """
-        Get the padded representation of the normals.
+        Get the padded representation of the normals,
+        or None if there are no normals.
 
         Returns:
             tensor of normals of shape (N, max(P_n), 3).
         """
         self._compute_padded()
         return self._normals_padded
 
-    def features_padded(self):
+    def features_padded(self) -> Optional[torch.Tensor]:
         """
-        Get the padded representation of the features.
+        Get the padded representation of the features,
+        or None if there are no features.
 
         Returns:
             tensor of features of shape (N, max(P_n), 3).
@@ -562,16 +572,18 @@ def _compute_padded(self, refresh: bool = False):
                 pad_value=0.0,
                 equisized=self.equisized,
             )
-            if self.normals_list() is not None:
+            normals_list = self.normals_list()
+            if normals_list is not None:
                 self._normals_padded = struct_utils.list_to_padded(
-                    self.normals_list(),
+                    normals_list,
                     (self._P, 3),
                     pad_value=0.0,
                     equisized=self.equisized,
                 )
-            if self.features_list() is not None:
+            features_list = self.features_list()
+            if features_list is not None:
                 self._features_padded = struct_utils.list_to_padded(
-                    self.features_list(),
+                    features_list,
                     (self._P, self._C),
                     pad_value=0.0,
                     equisized=self.equisized,
@@ -772,10 +784,12 @@ def get_cloud(self, index: int):
             )
         points = self.points_list()[index]
         normals, features = None, None
-        if self.normals_list() is not None:
-            normals = self.normals_list()[index]
-        if self.features_list() is not None:
-            features = self.features_list()[index]
+        normals_list = self.normals_list()
+        if normals_list is not None:
+            normals = normals_list[index]
+        features_list = self.features_list()
+        if features_list is not None:
+            features = features_list[index]
         return points, normals, features
 
     # TODO(nikhilar) Move function to a utils file.
@@ -1022,13 +1036,15 @@ def extend(self, N: int):
         new_points_list, new_normals_list, new_features_list = [], None, None
         for points in self.points_list():
             new_points_list.extend(points.clone() for _ in range(N))
-        if self.normals_list() is not None:
+        normals_list = self.normals_list()
+        if normals_list is not None:
             new_normals_list = []
-            for normals in self.normals_list():
+            for normals in normals_list:
                 new_normals_list.extend(normals.clone() for _ in range(N))
-        if self.features_list() is not None:
+        features_list = self.features_list()
+        if features_list is not None:
             new_features_list = []
-            for features in self.features_list():
+            for features in features_list:
                 new_features_list.extend(features.clone() for _ in range(N))
         return self.__class__(
             points=new_points_list, normals=new_normals_list, features=new_features_list