--- a
+++ b/examples/under-construction/newenv.py
@@ -0,0 +1,66 @@
+import os
+from osim.env import OsimEnv
+
+## Define an environment where we teach an agent to stand still
+# We use a walker model and define the objective to keep the center of mass still
+class StandingEnv(OsimEnv):
+    model_path = os.path.join(os.path.dirname(__file__), '../osim/models/gait9dof18musc.osim')    
+    time_limit = 300
+    ninput = 99
+    
+    def is_done(self):
+        # End the simulation if the pelvis is too low
+        state_desc = self.get_state_desc()
+        return state_desc["joint_pos"]["ground_pelvis"][2] < 0.7
+
+    def get_observation(self):
+        state_desc = self.get_state_desc()
+
+        # Augmented environment from the L2R challenge
+        res = []
+
+        # Map some of the state variables to the observation vector
+        for body_part in ["pelvis","head","torso","toes_l","toes_r","talus_l","talus_r"]:
+            res = res + state_desc["body_pos_rot"][body_part][2:]
+            res = res + state_desc["body_pos"][body_part][0:2]
+            res = res + state_desc["body_vel_rot"][body_part][2:]
+            res = res + state_desc["body_vel"][body_part][0:2]
+            res = res + state_desc["body_acc_rot"][body_part][2:]
+            res = res + state_desc["body_acc"][body_part][0:2]
+
+        for joint in ["ankle_l","ankle_r","back","ground_pelvis","hip_l","hip_r","knee_l","knee_r"]:
+            res = res + state_desc["joint_pos"][joint]
+            res = res + state_desc["joint_vel"][joint]
+            res = res + state_desc["joint_acc"][joint]
+
+        res = res + state_desc["misc"]["mass_center_pos"] + state_desc["misc"]["mass_center_vel"] + state_desc["misc"]["mass_center_acc"]
+
+        return res
+
+    def get_observation_space_size(self):
+        return 99
+
+    def reward(self):
+        # Get the current state and the last state
+        state_desc = self.get_state_desc()
+        prev_state_desc = self.get_prev_state_desc()
+        if not prev_state_desc:
+            return 0
+
+        # Penalize movement of the pelvis
+        res = -(prev_state_desc["misc"]["mass_center_pos"][0] - state_desc["misc"]["mass_center_pos"][0])**2\
+              -(prev_state_desc["misc"]["mass_center_pos"][1] - state_desc["misc"]["mass_center_pos"][1])**2
+
+        # Penalize very low position of the pelvis
+        res += -(state_desc["joint_pos"]["ground_pelvis"][2] < 0.8)
+        
+        return res
+
+env = StandingEnv(visualize=True)
+
+observation = env.reset()
+for i in range(200):
+    observation, reward, done, info = env.step(env.action_space.sample())
+    print("Reward %f" % reward)
+    if done:
+        env.reset()