mujoco

<mujoco>
  <compiler autolimits="true"/>

  <option integrator="implicitfast">
    <flag contact="disable" gravity="disable"/>
  </option>

  <statistic meansize=".05" extent=".9" center="0 0 .15"/>

  <visual>
    <headlight diffuse=".1 .1 .1" ambient=".15 .15 .15"/>
  </visual>

  <!--
  Three identical ball-jointed boxes, illustrating the three rotational setpoint semantics.
  The "per-axis" box has three independent position servos: each setpoint is interpreted on
  its own circle (wrapped), exact for rotations about a single gear axis. The "expmap" and
  "quat" boxes each have a single orientation actuator: the setpoints are interpreted
  jointly as an orientation on SO(3), exact for any combination of axes, commanded in the
  exponential-map and quaternion charts respectively.
  -->

  <asset>
    <texture name="checker" type="cube" builtin="checker" rgb1=".75 .55 .28" rgb2=".22 .18 .14" width="32" height="32"/>
    <material name="checker" texture="checker"/>
    <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>

  <default>
    <geom type="box" size=".07 .09 .05" material="checker"/>
    <position kp="5" dampratio="1"/>
    <default class="angle">
      <position ctrlrange="-6.2832 6.2832" ctrllimited="false"/>
    </default>
    <default class="quat">
      <position ctrlrange="-1 1" ctrllimited="true"/>
    </default>
    <site size="1e-5"/>
  </default>

  <worldbody>
    <light pos="0 0 10" type="point" diffuse=".75 .72 .65" intensity="1200000" range="20" attenuation="1 0 .04"/>
    <light pos="-.3 -.4 1.3" dir="0 .34 -.94" diffuse=".75 .72 .65" intensity="100000" range="4" cutoff="13" attenuation="1 0 0" exponent="60"/>
    <light pos="0 -.4 1.3" dir="0 .34 -.94" diffuse=".75 .72 .65" intensity="100000" range="4" cutoff="16" exponent="60" attenuation="1 0 .5"/>
    <light pos=".3 -.4 1.3" dir="0 .34 -.94" diffuse=".75 .72 .65" intensity="100000" range="4" cutoff="16" exponent="60" attenuation="1 0 .5"/>

    <light type="point" pos="0 -1.5 2" diffuse=".3 .35 .45" intensity="15000" range="8" castshadow="false" attenuation="1 0 .3"/>

    <geom name="floor" type="plane" size="2 2 .025" material="grid"/>

    <site name="per-axis" pos="-.3 0 .4"/>
    <body name="peraxis" pos="-.3 0 .2">
      <joint name="peraxis" type="ball"/>
      <geom/>
    </body>

    <site name="expmap" pos="0 0 .4"/>
    <body name="expmap" pos="0 0 .2">
      <joint name="expmap" type="ball"/>
      <geom/>
    </body>

    <site name="quat" pos=".3 0 .4"/>
    <body name="quat" pos=".3 0 .2">
      <joint name="quat" type="ball"/>
      <geom/>
    </body>
  </worldbody>

  <actuator>
    <position name="rx_peraxis" joint="peraxis" gear="1 0 0" class="angle"/>
    <position name="ry_peraxis" joint="peraxis" gear="0 1 0" class="angle"/>
    <position name="rz_peraxis" joint="peraxis" gear="0 0 1" class="angle"/>
    <orientation name="expmap" joint="expmap" kp="1" dampratio="1" class="angle"/>
    <orientation name="quat" joint="quat" input="quat" kp="1" dampratio="1" class="quat"/>
  </actuator>
</mujoco>