mujoco

<mujoco model="Bunnies">

  <include file="container.xml"/>

  <size memory="1G"/>

  <option solver="CG" tolerance="1e-6" timestep=".01"/>

  <asset>
    <mesh file="bunny.obj"/>
  </asset>

  <worldbody>
    <replicate count="5" offset=".17 0 0">
      <replicate count="5" offset="0 .17 0">
        <replicate count="5" offset="0 0 .17">
          <body pos="-0.35 -0.35 0.65">
            <freejoint/>
            <geom type="mesh" mesh="bunny" rgba="0.8 0.2 0.1 1"/>
          </body>
        </replicate>
      </replicate>
    </replicate>
  </worldbody>
</mujoco>