<!-- Copyright 2021 DeepMind Technologies Limited
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at
         http://www.apache.org/licenses/LICENSE-2.0
     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->

<mujoco>
  <!--
  the force sensor on body1 should register 2N (for the weight of both bodies).
  body2 is welded to body1 at an offset of 1m, so the torque sensor should register 1Nm.
  -->
  <option gravity="0 0 -1"/>

  <default>
    <!-- A cube of size 0.1^3 with density of 1000 has mass of 1. -->
    <geom size="0.05 0.05 0.05" type="box"/>
  </default>

  <worldbody>
    <body name="body1">
      <geom/>
      <site name="sensor"/>
    </body>
    <body name="body2" pos="0 1 0">
      <joint type="free"/>
      <geom/>
    </body>
  </worldbody>

  <equality>
    <weld body1="body1" body2="body2"/>
  </equality>

  <sensor>
    <force site="sensor" user="0 0 2"/>
    <torque site="sensor" user="1 0 0"/>
  </sensor>
</mujoco>
