From 700373dba3fe0016408acad140a4e559530f1613 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sun, 24 Mar 2024 13:10:24 +0200
Subject: [PATCH 01/12] Update humanoid_v5.py

---
 gymnasium/envs/mujoco/humanoid_v5.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gymnasium/envs/mujoco/humanoid_v5.py b/gymnasium/envs/mujoco/humanoid_v5.py
index b6b324b47..2b87c81f4 100644
--- a/gymnasium/envs/mujoco/humanoid_v5.py
+++ b/gymnasium/envs/mujoco/humanoid_v5.py
@@ -38,7 +38,7 @@ class HumanoidEnv(MujocoEnv, utils.EzPickle):
     :name: humanoid
     ```
 
-    The action space is a `Box(-1, 1, (17,), float32)`. An action represents the torques applied at the hinge joints.
+    The action space is a `Box(-0.4, 0.4, (17,), float32)`. An action represents the torques applied at the hinge joints.
 
     | Num | Action                                                                             | Control Min | Control Max | Name (in corresponding XML file) | Joint | Type (Unit)  |
     | --- | ---------------------------------------------------------------------------------- | ----------- | ----------- | -------------------------------- | ----- | ------------ |

From e169b8fc8b5ae3f5006dfddeb856cebc3fdd927b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sun, 24 Mar 2024 13:14:53 +0200
Subject: [PATCH 02/12] Update humanoidstandup_v5.py

---
 gymnasium/envs/mujoco/humanoidstandup_v5.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gymnasium/envs/mujoco/humanoidstandup_v5.py b/gymnasium/envs/mujoco/humanoidstandup_v5.py
index 8477ec0ca..6666274f7 100644
--- a/gymnasium/envs/mujoco/humanoidstandup_v5.py
+++ b/gymnasium/envs/mujoco/humanoidstandup_v5.py
@@ -32,7 +32,7 @@ class HumanoidStandupEnv(MujocoEnv, utils.EzPickle):
     :name: humanoid
     ```
 
-    The action space is a `Box(-1, 1, (17,), float32)`. An action represents the torques applied at the hinge joints.
+    The action space is a `Box(-0.4, 0.4, (17,), float32)`. An action represents the torques applied at the hinge joints.
 
     | Num | Action                                                                             | Control Min | Control Max | Name (in corresponding XML file) | Joint | Type (Unit)  |
     | --- | ---------------------------------------------------------------------------------- | ----------- | ----------- | -------------------------------- | ----- | ------------ |

From 2f656e3bd6deedd78440dc1805ace78a923ef42c Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 23 May 2024 09:41:36 +0300
Subject: [PATCH 03/12] Update mujoco_env.py

---
 gymnasium/envs/mujoco/mujoco_env.py | 199 ++++++++++++----------------
 1 file changed, 83 insertions(+), 116 deletions(-)

diff --git a/gymnasium/envs/mujoco/mujoco_env.py b/gymnasium/envs/mujoco/mujoco_env.py
index 5f2fa6396..70a7aaf15 100644
--- a/gymnasium/envs/mujoco/mujoco_env.py
+++ b/gymnasium/envs/mujoco/mujoco_env.py
@@ -34,19 +34,22 @@ def expand_model_path(model_path: str) -> str:
     return fullpath
 
 
-class BaseMujocoEnv(gym.Env[NDArray[np.float64], NDArray[np.float32]]):
-    """Superclass for all MuJoCo environments."""
+class MujocoEnv(BaseMujocoEnv):
+    """Superclass for MuJoCo based environments."""
 
     def __init__(
         self,
-        model_path,
-        frame_skip,
+        model_path: str,
+        frame_skip: int,
         observation_space: Optional[Space],
         render_mode: Optional[str] = None,
         width: int = DEFAULT_SIZE,
         height: int = DEFAULT_SIZE,
         camera_id: Optional[int] = None,
         camera_name: Optional[str] = None,
+        default_camera_config: Optional[Dict[str, Union[float, int]]] = None,
+        max_geom: int = 1000,
+        visual_options: Dict[int, bool] = {},
     ):
         """Base abstract class for mujoco based environments.
 
@@ -59,6 +62,9 @@ def __init__(
             height: The height of the render window.
             camera_id: The camera ID used.
             camera_name: The name of the camera used (can not be used in conjunction with `camera_id`).
+            default_camera_config: configuration for rendering camera.
+            max_geom: max number of rendered geometries.
+            visual_options: render flag options.
 
         Raises:
             OSError: when the `model_path` does not exist.
@@ -93,48 +99,79 @@ def __init__(
         self.camera_name = camera_name
         self.camera_id = camera_id
 
+        from gymnasium.envs.mujoco.mujoco_rendering import MujocoRenderer
+
+        self.mujoco_renderer = MujocoRenderer(
+            self.model,
+            self.data,
+            default_camera_config,
+            self.width,
+            self.height,
+            max_geom,
+            camera_id,
+            camera_name,
+            visual_options,
+        )
+
     def _set_action_space(self):
         bounds = self.model.actuator_ctrlrange.copy().astype(np.float32)
         low, high = bounds.T
         self.action_space = spaces.Box(low=low, high=high, dtype=np.float32)
         return self.action_space
 
-    # methods to override:
-    # ----------------------------
-    def step(
-        self, action: NDArray[np.float32]
-    ) -> Tuple[NDArray[np.float64], np.float64, bool, bool, Dict[str, np.float64]]:
-        raise NotImplementedError
-
-    def reset_model(self) -> NDArray[np.float64]:
+    def _initialize_simulation(
+        self,
+    ) -> Tuple["mujoco.MjModel", "mujoco.MjData"]:
         """
-        Reset the robot degrees of freedom (qpos and qvel).
-        Implement this in each subclass.
+        Initialize MuJoCo simulation data structures `mjModel` and `mjData`.
         """
-        raise NotImplementedError
+        model = mujoco.MjModel.from_xml_path(self.fullpath)
+        # MjrContext will copy model.vis.global_.off* to con.off*
+        model.vis.global_.offwidth = self.width
+        model.vis.global_.offheight = self.height
+        data = mujoco.MjData(model)
+        return model, data
 
-    def _initialize_simulation(self) -> Tuple[Any, Any]:
-        """
-        Initialize MuJoCo simulation data structures mjModel and mjData.
+    def set_state(self, qpos, qvel):
+        """Set the joints position qpos and velocity qvel of the model.
+
+        Note: `qpos` and `qvel` is not the full physics state for all mujoco models/environments https://mujoco.readthedocs.io/en/stable/APIreference/APItypes.html#mjtstate
         """
-        raise NotImplementedError
+        assert qpos.shape == (self.model.nq,) and qvel.shape == (self.model.nv,)
+        self.data.qpos[:] = np.copy(qpos)
+        self.data.qvel[:] = np.copy(qvel)
+        if self.model.na == 0:
+            self.data.act[:] = None
+        mujoco.mj_forward(self.model, self.data)
 
-    def _step_mujoco_simulation(self, ctrl, n_frames) -> None:
+    def _step_mujoco_simulation(self, ctrl, n_frames):
         """
         Step over the MuJoCo simulation.
         """
-        raise NotImplementedError
+        self.data.ctrl[:] = ctrl
 
-    def render(self) -> Union[NDArray[np.float64], None]:
+        mujoco.mj_step(self.model, self.data, nstep=n_frames)
+
+        # As of MuJoCo 2.0, force-related quantities like cacc are not computed
+        # unless there's a force sensor in the model.
+        # See https://github.com/openai/gym/issues/1541
+        mujoco.mj_rnePostConstraint(self.model, self.data)
+
+    def render(self):
         """
         Render a frame from the MuJoCo simulation as specified by the render_mode.
         """
-        raise NotImplementedError
+        return self.mujoco_renderer.render(self.render_mode)
+
+    def close(self):
+        """Close rendering contexts processes."""
+        if self.mujoco_renderer is not None:
+            self.mujoco_renderer.close()
+
+    def get_body_com(self, body_name):
+        """Return the cartesian position of a body frame."""
+        return self.data.body(body_name).xpos
 
-    # -----------------------------
-    def _get_reset_info(self) -> Dict[str, float]:
-        """Function that generates the `info` that is returned during a `reset()`."""
-        return {}
 
     def reset(
         self,
@@ -168,99 +205,29 @@ def do_simulation(self, ctrl, n_frames) -> None:
             )
         self._step_mujoco_simulation(ctrl, n_frames)
 
-    def close(self):
-        """Close all processes like rendering contexts"""
-        raise NotImplementedError
-
-    def get_body_com(self, body_name) -> NDArray[np.float64]:
-        """Return the cartesian position of a body frame"""
-        raise NotImplementedError
-
     def state_vector(self) -> NDArray[np.float64]:
-        """Return the position and velocity joint states of the model"""
+        """Return the position and velocity joint states of the model.
+        
+        Note: `qpos` and `qvel` does not constitute the full physics state for all `mujoco` environments see https://mujoco.readthedocs.io/en/stable/computation/index.html#the-state.
+        """
         return np.concatenate([self.data.qpos.flat, self.data.qvel.flat])
 
+    # methods to override:
+    # ----------------------------
+    def step(
+        self, action: NDArray[np.float32]
+    ) -> Tuple[NDArray[np.float64], np.float64, bool, bool, Dict[str, np.float64]]:
+        raise NotImplementedError
 
-class MujocoEnv(BaseMujocoEnv):
-    """Superclass for MuJoCo environments."""
-
-    def __init__(
-        self,
-        model_path,
-        frame_skip,
-        observation_space: Optional[Space],
-        render_mode: Optional[str] = None,
-        width: int = DEFAULT_SIZE,
-        height: int = DEFAULT_SIZE,
-        camera_id: Optional[int] = None,
-        camera_name: Optional[str] = None,
-        default_camera_config: Optional[Dict[str, Union[float, int]]] = None,
-        max_geom: int = 1000,
-        visual_options: Dict[int, bool] = {},
-    ):
-        super().__init__(
-            model_path,
-            frame_skip,
-            observation_space,
-            render_mode,
-            width,
-            height,
-            camera_id,
-            camera_name,
-        )
-
-        from gymnasium.envs.mujoco.mujoco_rendering import MujocoRenderer
-
-        self.mujoco_renderer = MujocoRenderer(
-            self.model,
-            self.data,
-            default_camera_config,
-            self.width,
-            self.height,
-            max_geom,
-            camera_id,
-            camera_name,
-            visual_options,
-        )
-
-    def _initialize_simulation(
-        self,
-    ) -> Tuple["mujoco._structs.MjModel", "mujoco._structs.MjData"]:
-        model = mujoco.MjModel.from_xml_path(self.fullpath)
-        # MjrContext will copy model.vis.global_.off* to con.off*
-        model.vis.global_.offwidth = self.width
-        model.vis.global_.offheight = self.height
-        data = mujoco.MjData(model)
-        return model, data
-
-    def set_state(self, qpos, qvel):
-        """Set the joints position qpos and velocity qvel of the model.
-
-        Note: `qpos` and `qvel` is not the full physics state for all mujoco models/environments https://mujoco.readthedocs.io/en/stable/APIreference/APItypes.html#mjtstate
+    def reset_model(self) -> NDArray[np.float64]:
         """
-        assert qpos.shape == (self.model.nq,) and qvel.shape == (self.model.nv,)
-        self.data.qpos[:] = np.copy(qpos)
-        self.data.qvel[:] = np.copy(qvel)
-        if self.model.na == 0:
-            self.data.act[:] = None
-        mujoco.mj_forward(self.model, self.data)
-
-    def _step_mujoco_simulation(self, ctrl, n_frames):
-        self.data.ctrl[:] = ctrl
-
-        mujoco.mj_step(self.model, self.data, nstep=n_frames)
-
-        # As of MuJoCo 2.0, force-related quantities like cacc are not computed
-        # unless there's a force sensor in the model.
-        # See https://github.com/openai/gym/issues/1541
-        mujoco.mj_rnePostConstraint(self.model, self.data)
-
-    def render(self):
-        return self.mujoco_renderer.render(self.render_mode)
+        Reset the robot degrees of freedom (qpos and qvel).
+        Implement this in each environment subclass.
+        """
+        raise NotImplementedError
 
-    def close(self):
-        if self.mujoco_renderer is not None:
-            self.mujoco_renderer.close()
+    def _get_reset_info(self) -> Dict[str, float]:
+        """Function that generates the `info` that is returned during a `reset()`."""
+        return {}
 
-    def get_body_com(self, body_name):
-        return self.data.body(body_name).xpos
+    # -----------------------------

From 13f67fe44cc3ff0f3874f2059e102691e6e07868 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Thu, 23 May 2024 09:42:59 +0300
Subject: [PATCH 04/12] Update test_mujoco_v5.py

---
 tests/envs/mujoco/test_mujoco_v5.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index afba1da47..c7a5fb0c0 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -600,10 +600,7 @@ def test_model_object_count(version: str):
         else:
             assert env.model.nbvh == 18
         assert env.model.njnt == 11
-        if version == "v4":
-            assert env.model.ngeom == 21
-        else:
-            assert env.model.ngeom == 20
+        assert env.model.ngeom == 21
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped

From 93d8a0cd5ec2b931111982b9cc36f3ffbde39626 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sat, 1 Jun 2024 08:40:16 +0000
Subject: [PATCH 05/12] `pre-commit`

---
 gymnasium/envs/mujoco/mujoco_env.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/gymnasium/envs/mujoco/mujoco_env.py b/gymnasium/envs/mujoco/mujoco_env.py
index 70a7aaf15..2f3e53050 100644
--- a/gymnasium/envs/mujoco/mujoco_env.py
+++ b/gymnasium/envs/mujoco/mujoco_env.py
@@ -1,5 +1,5 @@
 from os import path
-from typing import Any, Dict, Optional, Tuple, Union
+from typing import Dict, Optional, Tuple, Union
 
 import numpy as np
 from numpy.typing import NDArray
@@ -34,7 +34,7 @@ def expand_model_path(model_path: str) -> str:
     return fullpath
 
 
-class MujocoEnv(BaseMujocoEnv):
+class MujocoEnv(gym.Env):
     """Superclass for MuJoCo based environments."""
 
     def __init__(
@@ -172,7 +172,6 @@ def get_body_com(self, body_name):
         """Return the cartesian position of a body frame."""
         return self.data.body(body_name).xpos
 
-
     def reset(
         self,
         *,
@@ -207,7 +206,7 @@ def do_simulation(self, ctrl, n_frames) -> None:
 
     def state_vector(self) -> NDArray[np.float64]:
         """Return the position and velocity joint states of the model.
-        
+
         Note: `qpos` and `qvel` does not constitute the full physics state for all `mujoco` environments see https://mujoco.readthedocs.io/en/stable/computation/index.html#the-state.
         """
         return np.concatenate([self.data.qpos.flat, self.data.qvel.flat])

From 5ca94b43b89f67cf72970fe15a3c9d5de5c073b3 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Sat, 1 Jun 2024 11:48:11 +0300
Subject: [PATCH 06/12] Update test_mujoco_v5.py

---
 tests/envs/mujoco/test_mujoco_v5.py | 50 ++++++++++++++---------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index c7a5fb0c0..bf9c639e4 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -6,7 +6,7 @@
 import pytest
 
 import gymnasium as gym
-from gymnasium.envs.mujoco.mujoco_env import BaseMujocoEnv, MujocoEnv
+from gymnasium.envs.mujoco.mujoco_env import MujocoEnv
 from gymnasium.envs.mujoco.mujoco_py_env import BaseMujocoPyEnv
 from gymnasium.envs.mujoco.utils import check_mujoco_reset_state
 from gymnasium.error import Error
@@ -90,7 +90,7 @@ def test_verify_info_y_position(env_id: str):
 def test_verify_info_x_velocity(env_name: str, version: str):
     """Asserts that the environment `info['x_velocity']` is properly assigned."""
     env = gym.make(f"{env_name}-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_x = env.data.qpos[0]
@@ -107,7 +107,7 @@ def test_verify_info_x_velocity(env_name: str, version: str):
 def test_verify_info_y_velocity(env_id: str):
     """Asserts that the environment `info['y_velocity']` is properly assigned."""
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_y = env.data.qpos[1]
@@ -123,7 +123,7 @@ def test_verify_info_y_velocity(env_id: str):
 def test_verify_info_xy_velocity_xpos(env_id: str):
     """Asserts that the environment `info['x/y_velocity']` is properly assigned, for the ant environment which uses kinmatics for the velocity."""
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_xy = env.get_body_com("torso")[:2].copy()
@@ -146,7 +146,7 @@ def mass_center(model, data):
         return (np.sum(mass * xpos, axis=0) / np.sum(mass))[0:2].copy()
 
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     old_xy = mass_center(env.model, env.data)
@@ -178,7 +178,7 @@ def mass_center(model, data):
 def test_verify_reward_survive(env_name: str, version: str):
     """Assert that `reward_survive` is 0 on `terminal` states and not 0 on non-`terminal` states."""
     env = gym.make(f"{env_name}-{version}", reset_noise_scale=0).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset(seed=0)
     env.action_space.seed(1)
 
@@ -361,7 +361,7 @@ def test_ant_com(version: str):
     """Verify the kinmatic behaviour of the ant."""
     # `env` contains `data : MjData` and `model : MjModel`
     env = gym.make(f"Ant-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()  # randomly initlizies the `data.qpos` and `data.qvel`, calls mujoco.mj_forward(env.model, env.data)
 
     x_position_before = env.data.qpos[0]
@@ -382,7 +382,7 @@ def test_ant_com(version: str):
 def test_set_state(version: str):
     """Simple Test to verify that `mujocoEnv.set_state()` works correctly."""
     env = gym.make(f"Hopper-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
     new_qpos = np.array(
         [0.00136962, 1.24769787, -0.00459026, -0.00483472, 0.0031327, 0.00412756]
@@ -405,7 +405,7 @@ def test_set_state(version: str):
 def test_distance_from_origin_info(env_id: str):
     """Verify that `info"distance_from_origin"` is correct."""
     env = gym.make(env_id).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     _, _, _, _, info = env.step(env.action_space.sample())
@@ -487,7 +487,7 @@ def test_reset_info(env_name: str, version: str):
 def test_inverted_double_pendulum_max_height(version: str):
     """Verify the max height of Inverted Double Pendulum."""
     env = gym.make(f"InvertedDoublePendulum-{version}", reset_noise_scale=0).unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.reset()
 
     y = env.data.site_xpos[0][2]
@@ -498,7 +498,7 @@ def test_inverted_double_pendulum_max_height(version: str):
 def test_inverted_double_pendulum_max_height_old(version: str):
     """Verify the max height of Inverted Double Pendulum (v4 does not have `reset_noise_scale` argument)."""
     env = gym.make(f"InvertedDoublePendulum-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     env.set_state(env.init_qpos, env.init_qvel)
 
     y = env.data.site_xpos[0][2]
@@ -510,7 +510,7 @@ def test_inverted_double_pendulum_max_height_old(version: str):
 def test_model_object_count(version: str):
     """Verify that all the objects of the model are loaded, mostly useful for using non-mujoco simulator."""
     env = gym.make(f"Ant-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 15
     assert env.model.nv == 14
     assert env.model.nu == 8
@@ -521,7 +521,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"HalfCheetah-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 9
     assert env.model.nv == 9
     assert env.model.nu == 6
@@ -532,7 +532,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Hopper-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 6
     assert env.model.nv == 6
     assert env.model.nu == 3
@@ -543,7 +543,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Humanoid-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 24
     assert env.model.nv == 23
     assert env.model.nu == 17
@@ -554,7 +554,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 2
 
     env = gym.make(f"HumanoidStandup-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 24
     assert env.model.nv == 23
     assert env.model.nu == 17
@@ -565,7 +565,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 2
 
     env = gym.make(f"InvertedDoublePendulum-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 3
     assert env.model.nv == 3
     assert env.model.nu == 1
@@ -576,7 +576,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"InvertedPendulum-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 2
     assert env.model.nv == 2
     assert env.model.nu == 1
@@ -588,7 +588,7 @@ def test_model_object_count(version: str):
 
     if not (version == "v4" and mujoco.__version__ >= "3.0.0"):
         env = gym.make(f"Pusher-{version}").unwrapped
-        assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+        assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
         assert env.model.nq == 11
         assert env.model.nv == 11
         assert env.model.nu == 7
@@ -604,7 +604,7 @@ def test_model_object_count(version: str):
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 4
     assert env.model.nv == 4
     assert env.model.nu == 2
@@ -616,7 +616,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Swimmer-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 5
     assert env.model.nv == 5
     assert env.model.nu == 2
@@ -628,7 +628,7 @@ def test_model_object_count(version: str):
     assert env.model.ntendon == 0
 
     env = gym.make(f"Walker2d-{version}").unwrapped
-    assert isinstance(env, (BaseMujocoEnv, BaseMujocoPyEnv))
+    assert isinstance(env, (MujocoEnv, BaseMujocoPyEnv))
     assert env.model.nq == 9
     assert env.model.nv == 9
     assert env.model.nu == 6
@@ -666,8 +666,8 @@ def test_dt():
     env_b = gym.make(
         "Ant-v5", include_cfrc_ext_in_observation=False, frame_skip=1
     ).unwrapped
-    assert isinstance(env_a, BaseMujocoEnv)
-    assert isinstance(env_b, BaseMujocoEnv)
+    assert isinstance(env_a, MujocoEnv)
+    assert isinstance(env_b, MujocoEnv)
     env_b.model.opt.timestep = 0.05
 
     assert env_a.dt == env_b.dt
@@ -702,7 +702,7 @@ def test_dt():
 )
 def test_reset_noise_scale(env_id):
     """Checks that when `reset_noise_scale=0` we have deterministic initialization."""
-    env: BaseMujocoEnv = gym.make(env_id, reset_noise_scale=0).unwrapped
+    env = gym.make(env_id, reset_noise_scale=0).unwrapped
     env.reset()
 
     assert np.all(env.data.qpos == env.init_qpos)

From 52c04fb4aae4cb70ff034cccc1e88b73d03b9c04 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 5 Jun 2024 08:10:16 +0000
Subject: [PATCH 07/12] Trigger Build


From 0df947382e613972cfdc59f1478a8995dd4f495b Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 5 Jun 2024 11:25:03 +0300
Subject: [PATCH 08/12] Update test_mujoco_v5.py

---
 tests/envs/mujoco/test_mujoco_v5.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index bf9c639e4..e3ce08b11 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -600,7 +600,10 @@ def test_model_object_count(version: str):
         else:
             assert env.model.nbvh == 18
         assert env.model.njnt == 11
-        assert env.model.ngeom == 21
+        if version == "v4":
+            assert env.model.ngeom == 21
+        else:
+            assert env.model.ngeom == 20        
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped

From e8943b65de0db2d877170a660c1bb595e00da5fe Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 5 Jun 2024 09:21:29 +0000
Subject: [PATCH 09/12] `pre-commit`

---
 tests/envs/mujoco/test_mujoco_v5.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/envs/mujoco/test_mujoco_v5.py b/tests/envs/mujoco/test_mujoco_v5.py
index e3ce08b11..c7277d10b 100644
--- a/tests/envs/mujoco/test_mujoco_v5.py
+++ b/tests/envs/mujoco/test_mujoco_v5.py
@@ -603,7 +603,7 @@ def test_model_object_count(version: str):
         if version == "v4":
             assert env.model.ngeom == 21
         else:
-            assert env.model.ngeom == 20        
+            assert env.model.ngeom == 20
         assert env.model.ntendon == 0
 
     env = gym.make(f"Reacher-{version}").unwrapped

From 28e8131e08f62184da75b05987f9655aaa52f296 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 12:51:39 +0300
Subject: [PATCH 10/12] Update ant_v5.py

---
 gymnasium/envs/mujoco/ant_v5.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gymnasium/envs/mujoco/ant_v5.py b/gymnasium/envs/mujoco/ant_v5.py
index abe0db87c..3a9ffaacd 100644
--- a/gymnasium/envs/mujoco/ant_v5.py
+++ b/gymnasium/envs/mujoco/ant_v5.py
@@ -61,10 +61,10 @@ class AntEnv(MujocoEnv, utils.EzPickle):
     | Num | Observation                                                  | Min    | Max    | Name (in corresponding XML file)       | Joint | Type (Unit)              |
     |-----|--------------------------------------------------------------|--------|--------|----------------------------------------|-------|--------------------------|
     | 0   | z-coordinate of the torso (centre)                           | -Inf   | Inf    | root                                   | free  | position (m)             |
-    | 1   | x-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
-    | 2   | y-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
-    | 3   | z-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
-    | 4   | w-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
+    | 1   | w-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
+    | 2   | x-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
+    | 3   | y-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
+    | 4   | z-orientation of the torso (centre)                          | -Inf   | Inf    | root                                   | free  | angle (rad)              |
     | 5   | angle between torso and first link on front left             | -Inf   | Inf    | hip_1 (front_left_leg)                 | hinge | angle (rad)              |
     | 6   | angle between the two links on the front left                | -Inf   | Inf    | ankle_1 (front_left_leg)               | hinge | angle (rad)              |
     | 7   | angle between torso and first link on front right            | -Inf   | Inf    | hip_2 (front_right_leg)                | hinge | angle (rad)              |

From b44620fe171f42ebc7115331398e6ad69d8c57f7 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 12:52:13 +0300
Subject: [PATCH 11/12] Update humanoid_v5.py

---
 gymnasium/envs/mujoco/humanoid_v5.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gymnasium/envs/mujoco/humanoid_v5.py b/gymnasium/envs/mujoco/humanoid_v5.py
index 2b87c81f4..b0b96cc4d 100644
--- a/gymnasium/envs/mujoco/humanoid_v5.py
+++ b/gymnasium/envs/mujoco/humanoid_v5.py
@@ -92,10 +92,10 @@ class HumanoidEnv(MujocoEnv, utils.EzPickle):
     | Num | Observation                                                                                                     | Min  | Max | Name (in corresponding XML file) | Joint | Type (Unit)                |
     | --- | --------------------------------------------------------------------------------------------------------------- | ---- | --- | -------------------------------- | ----- | -------------------------- |
     | 0   | z-coordinate of the torso (centre)                                                                              | -Inf | Inf | root                             | free  | position (m)               |
-    | 1   | x-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
-    | 2   | y-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
-    | 3   | z-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
-    | 4   | w-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 1   | w-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 2   | x-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 3   | y-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 4   | z-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
     | 5   | z-angle of the abdomen (in lower_waist)                                                                         | -Inf | Inf | abdomen_z                        | hinge | angle (rad)                |
     | 6   | y-angle of the abdomen (in lower_waist)                                                                         | -Inf | Inf | abdomen_y                        | hinge | angle (rad)                |
     | 7   | x-angle of the abdomen (in pelvis)                                                                              | -Inf | Inf | abdomen_x                        | hinge | angle (rad)                |

From 44669a3e643e1e1d4edfb1fef4a418ad1f3c0006 Mon Sep 17 00:00:00 2001
From: Kallinteris Andreas
 <30759571+Kallinteris-Andreas@users.noreply.github.com>
Date: Wed, 25 Sep 2024 12:52:35 +0300
Subject: [PATCH 12/12] Update humanoidstandup_v5.py

---
 gymnasium/envs/mujoco/humanoidstandup_v5.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gymnasium/envs/mujoco/humanoidstandup_v5.py b/gymnasium/envs/mujoco/humanoidstandup_v5.py
index 6666274f7..b35426272 100644
--- a/gymnasium/envs/mujoco/humanoidstandup_v5.py
+++ b/gymnasium/envs/mujoco/humanoidstandup_v5.py
@@ -86,10 +86,10 @@ class HumanoidStandupEnv(MujocoEnv, utils.EzPickle):
     | Num | Observation                                                                                                     | Min  | Max | Name (in corresponding XML file) | Joint | Type (Unit)                |
     | --- | --------------------------------------------------------------------------------------------------------------- | ---- | --- | -------------------------------- | ----- | -------------------------- |
     | 0   | z-coordinate of the torso (centre)                                                                              | -Inf | Inf | root                             | free  | position (m)               |
-    | 1   | x-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
-    | 2   | y-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
-    | 3   | z-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
-    | 4   | w-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 1   | w-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 2   | x-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 3   | y-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
+    | 4   | z-orientation of the torso (centre)                                                                             | -Inf | Inf | root                             | free  | angle (rad)                |
     | 5   | z-angle of the abdomen (in lower_waist)                                                                         | -Inf | Inf | abdomen_z                        | hinge | angle (rad)                |
     | 6   | y-angle of the abdomen (in lower_waist)                                                                         | -Inf | Inf | abdomen_y                        | hinge | angle (rad)                |
     | 7   | x-angle of the abdomen (in pelvis)                                                                              | -Inf | Inf | abdomen_x                        | hinge | angle (rad)                |