mujoco

<mujoco>
  <size memory="200M"/>

  <option timestep="1e-2">
    <flag sleep="enable"/>
  </option>

  <worldbody>
    <replicate offset="0 0 2.5" count="7">
      <replicate offset="4 0 0" count="7">
        <replicate offset="0 2 0" count="7">
          <frame>
            <geom size=".4"/>
            <frame pos="-.4 0 0">
              <geom type="cylinder" size="0.1" fromto="0 0 0 0 0 1"/>
            </frame>
          </frame>

          <geom type="box" size="0.1" fromto=".6 0 0 .6 0 1"/>

          <frame pos="1 0 0">
            <geom type="capsule" size="0.1" fromto="0 0 0 0 0 1"/>
            <frame pos="0 0 1">
              <geom type="capsule" size="0.1" fromto="0 0 0 0 0 1"/>
            </frame>
          </frame>

          <geom type="box" size="0.1" fromto="1.4 0 0 1.4 0 1"/>

          <frame pos="2 0 0">
            <geom type="box" size=".2 .2 .2"/>
            <frame pos=".2 0 0">
              <geom type="cylinder" size="0.1" fromto="0 0 0 0 0 1"/>
            </frame>
          </frame>
        </replicate>
      </replicate>
    </replicate>
  </worldbody>
</mujoco>