Fix Transform3d.stack of compositions

Summary:
Add a test for Transform3d.stack, and make it work with composed transformations.

Fixes https://github.com/facebookresearch/pytorch3d/issues/1072 .

Reviewed By: patricklabatut

Differential Revision: D34211920

fbshipit-source-id: bfbd0895494ca2ad3d08a61bc82ba23637e168cc

pytorch3d/renderer/cameras.py

@@ -1649,7 +1649,7 @@ def look_at_view_transform(
     elev=0.0,
     azim=0.0,
     degrees: bool = True,
-    eye: Optional[Sequence] = None,
+    eye: Optional[Union[Sequence, torch.Tensor]] = None,
     at=((0, 0, 0),),  # (1, 3)
     up=((0, 1, 0),),  # (1, 3)
     device: Device = "cpu",

pytorch3d/transforms/transform3d.py

@@ -196,10 +196,10 @@ class Transform3d:
             index = [index]
         return self.__class__(matrix=self.get_matrix()[index])
 
-    def compose(self, *others):
+    def compose(self, *others: "Transform3d") -> "Transform3d":
         """
-        Return a new Transform3d with the transforms to compose stored as
-        an internal list.
+        Return a new Transform3d representing the composition of self with the
+        given other transforms, which will be stored as an internal list.
 
         Args:
             *others: Any number of Transform3d objects
@@ -216,7 +216,7 @@ class Transform3d:
         out._transforms = self._transforms + list(others)
         return out
 
-    def get_matrix(self):
+    def get_matrix(self) -> torch.Tensor:
         """
         Return a matrix which is the result of composing this transform
         with others stored in self.transforms. Where necessary transforms
@@ -240,13 +240,13 @@ class Transform3d:
                 composed_matrix = _broadcast_bmm(composed_matrix, other_matrix)
         return composed_matrix
 
-    def _get_matrix_inverse(self):
+    def _get_matrix_inverse(self) -> torch.Tensor:
         """
         Return the inverse of self._matrix.
         """
         return torch.inverse(self._matrix)
 
-    def inverse(self, invert_composed: bool = False):
+    def inverse(self, invert_composed: bool = False) -> "Transform3d":
         """
         Returns a new Transform3d object that represents an inverse of the
         current transformation.
@@ -295,14 +295,24 @@ class Transform3d:
 
         return tinv
 
-    def stack(self, *others):
+    def stack(self, *others: "Transform3d") -> "Transform3d":
+        """
+        Return a new batched Transform3d representing the batch elements from
+        self and all the given other transforms all batched together.
+
+        Args:
+            *others: Any number of Transform3d objects
+
+        Returns:
+            A new Transform3d.
+        """
         transforms = [self] + list(others)
-        matrix = torch.cat([t._matrix for t in transforms], dim=0)
+        matrix = torch.cat([t.get_matrix() for t in transforms], dim=0)
         out = Transform3d(dtype=self.dtype, device=self.device)
         out._matrix = matrix
         return out
 
-    def transform_points(self, points, eps: Optional[float] = None):
+    def transform_points(self, points, eps: Optional[float] = None) -> torch.Tensor:
         """
         Use this transform to transform a set of 3D points. Assumes row major
         ordering of the input points.
@@ -347,7 +357,7 @@ class Transform3d:
 
         return points_out
 
-    def transform_normals(self, normals):
+    def transform_normals(self, normals) -> torch.Tensor:
         """
         Use this transform to transform a set of normal vectors.
 
@@ -379,19 +389,19 @@ class Transform3d:
 
         return normals_out
 
-    def translate(self, *args, **kwargs):
+    def translate(self, *args, **kwargs) -> "Transform3d":
         return self.compose(Translate(device=self.device, *args, **kwargs))
 
-    def scale(self, *args, **kwargs):
+    def scale(self, *args, **kwargs) -> "Transform3d":
         return self.compose(Scale(device=self.device, *args, **kwargs))
 
-    def rotate(self, *args, **kwargs):
+    def rotate(self, *args, **kwargs) -> "Transform3d":
         return self.compose(Rotate(device=self.device, *args, **kwargs))
 
-    def rotate_axis_angle(self, *args, **kwargs):
+    def rotate_axis_angle(self, *args, **kwargs) -> "Transform3d":
         return self.compose(RotateAxisAngle(device=self.device, *args, **kwargs))
 
-    def clone(self):
+    def clone(self) -> "Transform3d":
         """
         Deep copy of Transforms object. All internal tensors are cloned
         individually.
@@ -411,7 +421,7 @@ class Transform3d:
         device: Device,
         copy: bool = False,
         dtype: Optional[torch.dtype] = None,
-    ):
+    ) -> "Transform3d":
         """
         Match functionality of torch.Tensor.to()
         If copy = True or the self Tensor is on a different device, the
@@ -448,10 +458,10 @@ class Transform3d:
         ]
         return other
 
-    def cpu(self):
+    def cpu(self) -> "Transform3d":
         return self.to("cpu")
 
-    def cuda(self):
+    def cuda(self) -> "Transform3d":
         return self.to("cuda")
 
 
@@ -486,7 +496,7 @@ class Translate(Transform3d):
         mat[:, 3, :3] = xyz
         self._matrix = mat
 
-    def _get_matrix_inverse(self):
+    def _get_matrix_inverse(self) -> torch.Tensor:
         """
         Return the inverse of self._matrix.
         """
@@ -533,7 +543,7 @@ class Scale(Transform3d):
         mat[:, 2, 2] = xyz[:, 2]
         self._matrix = mat
 
-    def _get_matrix_inverse(self):
+    def _get_matrix_inverse(self) -> torch.Tensor:
         """
         Return the inverse of self._matrix.
         """
@@ -575,7 +585,7 @@ class Rotate(Transform3d):
         mat[:, :3, :3] = R
         self._matrix = mat
 
-    def _get_matrix_inverse(self):
+    def _get_matrix_inverse(self) -> torch.Tensor:
         """
         Return the inverse of self._matrix.
         """
@@ -622,7 +632,7 @@ class RotateAxisAngle(Rotate):
         super().__init__(device=angle.device, R=R)
 
 
-def _handle_coord(c, dtype: torch.dtype, device: torch.device):
+def _handle_coord(c, dtype: torch.dtype, device: torch.device) -> torch.Tensor:
     """
     Helper function for _handle_input.
 
@@ -649,7 +659,7 @@ def _handle_input(
     device: Optional[Device],
     name: str,
     allow_singleton: bool = False,
-):
+) -> torch.Tensor:
     """
     Helper function to handle parsing logic for building transforms. The output
     is always a tensor of shape (N, 3), but there are several types of allowed
@@ -707,7 +717,9 @@ def _handle_input(
     return xyz
 
 
-def _handle_angle_input(x, dtype: torch.dtype, device: Optional[Device], name: str):
+def _handle_angle_input(
+    x, dtype: torch.dtype, device: Optional[Device], name: str
+) -> torch.Tensor:
     """
     Helper function for building a rotation function using angles.
     The output is always of shape (N,).
@@ -725,7 +737,7 @@ def _handle_angle_input(x, dtype: torch.dtype, device: Optional[Device], name: s
         return _handle_coord(x, dtype, device_)
 
 
-def _broadcast_bmm(a, b):
+def _broadcast_bmm(a, b) -> torch.Tensor:
     """
     Batch multiply two matrices and broadcast if necessary.
 

tests/test_transforms.py

@@ -10,6 +10,7 @@ import unittest
 
 import torch
 from common_testing import TestCaseMixin
+from pytorch3d.transforms import random_rotations
 from pytorch3d.transforms.so3 import so3_exp_map
 from pytorch3d.transforms.transform3d import (
     Rotate,
@@ -21,6 +22,9 @@ from pytorch3d.transforms.transform3d import (
 
 
 class TestTransform(TestCaseMixin, unittest.TestCase):
+    def setUp(self) -> None:
+        torch.manual_seed(42)
+
     def test_to(self):
         tr = Translate(torch.FloatTensor([[1.0, 2.0, 3.0]]))
         R = torch.FloatTensor([[0.0, 1.0, 0.0], [0.0, 0.0, 1.0], [1.0, 0.0, 0.0]])
@@ -406,6 +410,28 @@ class TestTransform(TestCaseMixin, unittest.TestCase):
             with self.assertRaises(IndexError):
                 t3d_selected = t3d[invalid_index]
 
+    def test_stack(self):
+        rotations = random_rotations(3)
+        transform3 = Transform3d().rotate(rotations).translate(torch.full((3, 3), 0.3))
+        transform1 = Scale(37)
+        transform4 = transform1.stack(transform3)
+        self.assertEqual(len(transform1), 1)
+        self.assertEqual(len(transform3), 3)
+        self.assertEqual(len(transform4), 4)
+        self.assertClose(
+            transform4.get_matrix(),
+            torch.cat([transform1.get_matrix(), transform3.get_matrix()]),
+        )
+        points = torch.rand(4, 5, 3)
+        new_points_expect = torch.cat(
+            [
+                transform1.transform_points(points[:1]),
+                transform3.transform_points(points[1:]),
+            ]
+        )
+        new_points = transform4.transform_points(points)
+        self.assertClose(new_points, new_points_expect)
+
 
 class TestTranslate(unittest.TestCase):
     def test_python_scalar(self):