Ensure input rotation matrices are 3x3

Author: LemonPi

src/pytorch_kinematics/transforms/transform3d.py

@@ -574,7 +574,7 @@ def __init__(
         elif R.shape[-1] == 3 and (len(R.shape) == 1 or R.shape[-2] != 3):
             R = euler_angles_to_matrix(R, DEFAULT_EULER_CONVENTION)
         else:
-            _check_valid_rotation_matrix(R, tol=orthogonal_tol)
+            _check_valid_rotation_matrix(R.view(-1, 3, 3), tol=orthogonal_tol)
         if R.dim() == 2:
             R = R[None]