<mujoco>
  <visual>
   <headlight ambient="0.5 0.5 0.5"/>
    </visual>
  <worldbody>
    <geom type="plane" size="100 1 0.1" rgba=".9 0 0 1"/>
    <geom type="cylinder" pos="5 0 1" size="0.2 1" rgba=".9 .9 .9 1"/>

    <body pos="0 0 .1">
      <joint type="free"/>
      <geom type="sphere" size=".1" rgba="0 .9 0 1" mass="1"/>
    </body>

    <body pos="5 0 2.1">
      <joint type="free"/>
      <geom type="box" size="0.1 0.1 0.1" rgba=".9 .9 0 1" mass="0.1"/>
    </body>
  </worldbody>
</mujoco>
