Make Transform3d.to() not ignore dtype

Summary: Make Transform3d.to() not ignore a different dtype when device is the same and no copy is requested. Fix other methods where dtype is ignored.

Reviewed By: nikhilaravi

Differential Revision: D28981171

fbshipit-source-id: 4528e6092f4a693aecbe8131ede985fca84e84cf

Author: patricklabatut

pytorch3d/transforms/transform3d.py

@@ -162,13 +162,15 @@ def __init__(
                 raise ValueError(
                     '"matrix" has to be a tensor of shape (minibatch, 4, 4)'
                 )
-            # set the device from matrix
+            # set dtype and device from matrix
+            dtype = matrix.dtype
             device = matrix.device
             self._matrix = matrix.view(-1, 4, 4)
 
         self._transforms = []  # store transforms to compose
         self._lu = None
         self.device = make_device(device)
+        self.dtype = dtype
 
     def __len__(self):
         return self.get_matrix().shape[0]
@@ -200,7 +202,7 @@ def compose(self, *others):
         Returns:
             A new Transform3d with the stored transforms
         """
-        out = Transform3d(device=self.device)
+        out = Transform3d(dtype=self.dtype, device=self.device)
         out._matrix = self._matrix.clone()
         for other in others:
             if not isinstance(other, Transform3d):
@@ -259,7 +261,7 @@ def inverse(self, invert_composed: bool = False):
             transformation.
         """
 
-        tinv = Transform3d(device=self.device)
+        tinv = Transform3d(dtype=self.dtype, device=self.device)
 
         if invert_composed:
             # first compose then invert
@@ -278,7 +280,7 @@ def inverse(self, invert_composed: bool = False):
                 # right-multiplies by the inverse of self._matrix
                 # at the end of the composition.
                 tinv._transforms = [t.inverse() for t in reversed(self._transforms)]
-                last = Transform3d(device=self.device)
+                last = Transform3d(dtype=self.dtype, device=self.device)
                 last._matrix = i_matrix
                 tinv._transforms.append(last)
             else:
@@ -291,7 +293,7 @@ def inverse(self, invert_composed: bool = False):
     def stack(self, *others):
         transforms = [self] + list(others)
         matrix = torch.cat([t._matrix for t in transforms], dim=0)
-        out = Transform3d()
+        out = Transform3d(dtype=self.dtype, device=self.device)
         out._matrix = matrix
         return out
 
@@ -392,7 +394,7 @@ def clone(self):
         Returns:
             new Transforms object.
         """
-        other = Transform3d(device=self.device)
+        other = Transform3d(dtype=self.dtype, device=self.device)
         if self._lu is not None:
             other._lu = [elem.clone() for elem in self._lu]
         other._matrix = self._matrix.clone()
@@ -422,17 +424,22 @@ def to(
           Transform3d object.
         """
         device_ = make_device(device)
-        if not copy and self.device == device_:
+        dtype_ = self.dtype if dtype is None else dtype
+        skip_to = self.device == device_ and self.dtype == dtype_
+
+        if not copy and skip_to:
             return self
 
         other = self.clone()
-        if self.device == device_:
+
+        if skip_to:
             return other
 
         other.device = device_
-        other._matrix = self._matrix.to(device=device_, dtype=dtype)
+        other.dtype = dtype_
+        other._matrix = other._matrix.to(device=device_, dtype=dtype_)
         other._transforms = [
-            t.to(device_, copy=copy, dtype=dtype) for t in other._transforms
+            t.to(device_, copy=copy, dtype=dtype_) for t in other._transforms
         ]
         return other
 

tests/test_transforms.py

@@ -28,23 +28,45 @@ def test_to(self):
         cpu_t = t.to("cpu")
         self.assertEqual(cpu_device, cpu_t.device)
         self.assertEqual(cpu_device, t.device)
+        self.assertEqual(torch.float32, cpu_t.dtype)
+        self.assertEqual(torch.float32, t.dtype)
         self.assertIs(t, cpu_t)
 
         cpu_t = t.to(cpu_device)
         self.assertEqual(cpu_device, cpu_t.device)
         self.assertEqual(cpu_device, t.device)
+        self.assertEqual(torch.float32, cpu_t.dtype)
+        self.assertEqual(torch.float32, t.dtype)
         self.assertIs(t, cpu_t)
 
+        cpu_t = t.to(dtype=torch.float64, device=cpu_device)
+        self.assertEqual(cpu_device, cpu_t.device)
+        self.assertEqual(cpu_device, t.device)
+        self.assertEqual(torch.float64, cpu_t.dtype)
+        self.assertEqual(torch.float32, t.dtype)
+        self.assertIsNot(t, cpu_t)
+
         cuda_device = torch.device("cuda")
 
         cuda_t = t.to("cuda")
         self.assertEqual(cuda_device, cuda_t.device)
         self.assertEqual(cpu_device, t.device)
+        self.assertEqual(torch.float32, cuda_t.dtype)
+        self.assertEqual(torch.float32, t.dtype)
         self.assertIsNot(t, cuda_t)
 
         cuda_t = t.to(cuda_device)
         self.assertEqual(cuda_device, cuda_t.device)
         self.assertEqual(cpu_device, t.device)
+        self.assertEqual(torch.float32, cuda_t.dtype)
+        self.assertEqual(torch.float32, t.dtype)
+        self.assertIsNot(t, cuda_t)
+
+        cuda_t = t.to(dtype=torch.float64, device=cuda_device)
+        self.assertEqual(cuda_device, cuda_t.device)
+        self.assertEqual(cpu_device, t.device)
+        self.assertEqual(torch.float64, cuda_t.dtype)
+        self.assertEqual(torch.float32, t.dtype)
         self.assertIsNot(t, cuda_t)
 
         cpu_points = torch.rand(9, 3)