Fix #123.

PiperOrigin-RevId: 758546904
Change-Id: I93d0559c245de1b8504c3c33604969cd8de77b16

Author: btaba

mujoco_playground/_src/dm_control_suite/walker.py

@@ -119,7 +119,7 @@ def step(self, state: mjx_env.State, action: jax.Array) -> mjx_env.State:
 
   def _get_obs(self, data: mjx.Data, info: dict[str, Any]) -> jax.Array:
     del info  # Unused.
-    orientations = data.xmat[1:, [[0, 0], [0, 2]]].ravel()
+    orientations = data.xmat[1:, [0, 0], [0, 2]].ravel()
     height = data.xmat[self._torso_id, 2, 2]
     velocity = data.qvel
     return jp.concatenate([