mujoco

<mujoco>
  <asset>
    <texture type="skybox" builtin="gradient" rgb1=".3 .5 .7" rgb2="0 0 0" width="32" height="512"/>
    <texture name="grid" type="2d" builtin="checker" width="512" height="512" rgb1=".1 .2 .3" rgb2=".2 .3 .4"/>
    <material name="grid" texture="grid" texrepeat="1 1" texuniform="true" reflectance=".2"/>
  </asset>

  <statistic extent="1"/>

  <!-- switch the integrator to "implicit" for better gyroscopic stabillity -->
  <option timestep="0.01" integrator="implicitfast"/>

  <worldbody>
    <geom pos="0 0 -.5" type="plane" size="100 100 .1" zaxis=".5 0 1" material="grid"/>
    <body pos="0 0 .3">
      <freejoint/>
      <geom type="ellipsoid" size="0.15 0.1 0.07" euler="20 40 60"/>
      <light pos="0 0 1.5" mode="track"/>
      <camera pos="0 -1.498 0.1" xyaxes="1 0 0 0 0 1" mode="track"/>
    </body>
  </worldbody>
</mujoco>