v1.4.4

docsource/source/index.rst

@@ -231,6 +231,8 @@ Bits of code were adapted from SciPy. Documentation is generated, distributed an
 
 Changelog
 ==========
+Version 1.4.4:
+    - Added :func:`~roma.utils.identity_quat()`.
 Version 1.4.3: 
     - Fix normalization bug in :func:`~roma.utils.quat_composition()` (thanks jamiesalter for reporting).
 Version 1.4.2:

roma/utils.py

@@ -97,6 +97,25 @@ def random_rotvec(size = tuple(), dtype=torch.float, device=None):
     quat = random_unitquat(size, dtype=dtype, device=device)
     return roma.mappings.unitquat_to_rotvec(quat)
 
+def identity_quat(size = tuple(), dtype=torch.float, device=None):
+    """
+    Return a batch of identity unit quaternions.
+
+    Args:
+        size (tuple or int): batch size. Use for example ``tuple()`` to generate a single element, and ``(5,2)`` to generate a 5x2 batch.
+    Returns:
+        batch of identity quaternions (size x 4 tensor, XYZW convention).
+    Note:
+        All returned batch quaternions refer to the same memory location.
+        Consider cloning the output tensor prior performing any in-place operations.
+    """
+    if type(size) == int:
+        size = (size,)
+    quat = torch.zeros(4, dtype=dtype, device=device)
+    quat[...,-1] = 1.
+    quat = quat.expand(list(size) + [-1])
+    return quat
+
 def rotmat_cosine_angle(R):
     """
     Returns the cosine angle of the input 3x3 rotation matrix R.
@@ -110,7 +129,6 @@ def rotmat_cosine_angle(R):
     assert R.shape[-2:] == (3,3), "Expecting a ...x3x3 batch of rotation matrices"
     return  0.5 * (R[...,0,0] + R[...,1,1] + R[...,2,2] - 1.0)
 
-
 _ONE_OVER_2SQRT2 = 1.0 / (2 * np.sqrt(2))
 def rotmat_geodesic_distance(R1, R2, clamping=1.0):
     """

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
     name="roma",
-    version="1.4.3",
+    version="1.4.4",
     author="Romain Brégier",
     author_email="[email protected]",
     description="A lightweight library to deal with 3D rotations in PyTorch.",

test/test_utils.py

@@ -64,6 +64,19 @@ def test_other_geodesic_distance(self):
             alpha_rotvec = roma.rotvec_geodesic_distance(rotvec1, rotvec2)
             self.assertTrue(is_close(alpha_rotvec, alpha_q))
 
+    def test_identity_quat(self):
+        q = roma.identity_quat()
+        self.assertTrue(q.shape == (4,))
+        self.assertTrue(is_close(q, roma.quat_inverse(q)))
+
+        q = roma.identity_quat(5)
+        self.assertTrue(q.shape == (5,4))
+        self.assertTrue(is_close(q, roma.quat_inverse(q)))
+
+        q = roma.identity_quat((3,2))
+        self.assertTrue(q.shape == (3,2,4))
+        self.assertTrue(is_close(q, roma.quat_inverse(q)))
+
     def test_random_unitquat(self):
         q = roma.random_unitquat((3,5))
         self.assertTrue(q.shape == (3,5,4))