mujoco

<mujoco model="Convex-Convex collisions">
  <option>
    <flag gravity="disable"/>
  </option>

  <asset>
    <mesh name="halfbox1" scale=".2 .3 .1"
          vertex="0 0 0  1 0 0  0 1 0  1 1 0
                  0 0 1  1 0 1  0 1 1 "/>
    <mesh name="halfbox2" scale=".2 .3 .1"
          vertex="1 0 0  0 1 0  1 1 0
                  0 0 1  1 0 1  0 1 1 "/>
    <hfield name="hfield" nrow="3" ncol="4" size="1 1 .1 .08"
            elevation="1 0 1 2
                       0 2 1 1
                       1 0 1 0"/>
  </asset>

  <default>
    <geom rgba=".2 .2 .6 1"/>
  </default>

  <worldbody>
    <light pos=".5 0 3"/>
    <light pos="-.5 0 3"/>

    <geom name="hfield" type="hfield" hfield="hfield" rgba="0.5 0.5 0.5 1"/>

    <body pos=".2 0 .6">
      <freejoint/>
      <geom name="sphere" type="sphere" size=".15"/>
    </body>

    <body pos="0 0 .3">
      <freejoint/>
      <geom name="ellipsoid" type="ellipsoid" size=".1 .1 .2"/>
    </body>

    <body pos=".4 0 .3">
      <freejoint/>
      <geom name="cylinder" type="cylinder" size=".1 .15"/>
    </body>

    <body pos="-.5 0 .3">
      <freejoint/>
      <geom name="box" type="box" size=".2 .15 .1"/>
    </body>

    <body pos="-.5 0 .6">
      <freejoint/>
      <geom name="mesh1" type="mesh" mesh="halfbox1"/>
    </body>

    <body pos="-.5 -.6 .3">
      <freejoint/>
      <geom name="mesh2" type="mesh" mesh="halfbox2"/>
    </body>
  </worldbody>

  <sensor>
    <fromto geom1="ellipsoid" geom2="box" cutoff="1"/>
    <fromto geom1="ellipsoid" geom2="cylinder" cutoff="1"/>
    <fromto geom1="ellipsoid" geom2="mesh2" cutoff="1"/>
    <fromto geom1="mesh1" geom2="sphere" cutoff="1"/>
    <fromto geom1="mesh1" geom2="box" cutoff="1"/>
    <fromto geom1="mesh1" geom2="mesh2" cutoff="1"/>

    <fromto geom1="ellipsoid" geom2="box" cutoff="0.2"/>
    <fromto geom1="ellipsoid" geom2="cylinder" cutoff="0.2"/>
    <fromto geom1="ellipsoid" geom2="mesh2" cutoff="0.2"/>
    <fromto geom1="mesh1" geom2="sphere" cutoff="0.2"/>
    <fromto geom1="mesh1" geom2="box" cutoff="0.2"/>
    <fromto geom1="mesh1" geom2="mesh2" cutoff="0.2"/>
  </sensor>
</mujoco>