bullet3

<mujoco model="walker2d">
  <compiler angle="degree" coordinate="global" inertiafromgeom="true"/>
  <default>
    <joint armature="0.01" damping=".1" limited="true"/>
    <geom conaffinity="0" condim="3" contype="1" density="1000" friction="0.8 .1 .1" rgba="0.8 0.6 .4 1"/>
  </default>
  <option integrator="RK4" timestep="0.002"/>
  <worldbody>
    <!-- CHANGES: see hopper.xml -->
    <body name="torso">
      <joint armature="0" axis="1 0 0" damping="0" limited="false" name="ignorex" pos="0 0 0" stiffness="0" type="slide"/>
      <joint armature="0" axis="0 0 1" damping="0" limited="false" name="ignorez" pos="0 0 0" ref="1.25" stiffness="0" type="slide"/>
      <joint armature="0" axis="0 1 0" damping="0" limited="false" name="ignorey" pos="0 0 0" stiffness="0" type="hinge"/>
      <geom fromto="0 0 1.45 0 0 1.05" name="torso_geom" size="0.05" type="capsule"/>
      <body name="thigh">
        <joint axis="0 -1 0" name="thigh_joint" pos="0 0 1.05" range="-150 0" type="hinge"/>
        <geom fromto="0 0 1.05 0 0 0.6" name="thigh_geom" size="0.05" type="capsule"/>
        <body name="leg">
          <joint axis="0 -1 0" name="leg_joint" pos="0 0 0.6" range="-150 0" type="hinge"/>
          <geom fromto="0 0 0.6 0 0 0.1" name="leg_geom" size="0.04" type="capsule"/>
          <body name="foot">
            <joint axis="0 -1 0" name="foot_joint" pos="0 0 0.1" range="-45 45" type="hinge"/>
            <geom fromto="-0.0 0 0.1 0.2 0 0.1" name="foot_geom" size="0.06" type="capsule"/>
          </body>
        </body>
      </body>
      <!-- copied and then replace thigh->thigh_left, leg->leg_left, foot->foot_right -->
      <body name="thigh_left">
        <joint axis="0 -1 0" name="thigh_left_joint" pos="0 0 1.05" range="-150 0" type="hinge"/>
        <geom fromto="0 0 1.05 0 0 0.6" name="thigh_left_geom" rgba=".7 .3 .6 1" size="0.05" type="capsule"/>
        <body name="leg_left">
          <joint axis="0 -1 0" name="leg_left_joint" pos="0 0 0.6" range="-150 0" type="hinge"/>
          <geom fromto="0 0 0.6 0 0 0.1" name="leg_left_geom" rgba=".7 .3 .6 1" size="0.04" type="capsule"/>
          <body name="foot_left">
            <joint axis="0 -1 0" name="foot_left_joint" pos="0 0 0.1" range="-45 45" type="hinge"/>
            <geom fromto="-0.0 0 0.1 0.2 0 0.1" name="foot_left_geom" rgba=".7 .3 .6 1" size="0.06" type="capsule"/>
          </body>
        </body>
      </body>
    </body>
  </worldbody>
  <actuator>
    <!-- <motor joint="torso_joint" ctrlrange="-100.0 100.0" isctrllimited="true"/>-->
    <motor ctrllimited="true" ctrlrange="-1.0 1.0" gear="100" joint="thigh_joint"/>
    <motor ctrllimited="true" ctrlrange="-1.0 1.0" gear="100" joint="leg_joint"/>
    <motor ctrllimited="true" ctrlrange="-1.0 1.0" gear="100" joint="foot_joint"/>
    <motor ctrllimited="true" ctrlrange="-1.0 1.0" gear="100" joint="thigh_left_joint"/>
    <motor ctrllimited="true" ctrlrange="-1.0 1.0" gear="100" joint="leg_left_joint"/>
    <motor ctrllimited="true" ctrlrange="-1.0 1.0" gear="100" joint="foot_left_joint"/>
    <!-- <motor joint="finger2_rot" ctrlrange="-20.0 20.0" isctrllimited="true"/>-->
  </actuator>
</mujoco>