mujoco/environment/flat.xml

<mujoco model="flat">
  <statistic center="0 0 0.55" extent="1.1"/>

  <visual>
    <headlight diffuse="0.6 0.6 0.6" ambient="0.3 0.3 0.3" specular="0 0 0"/>
    <rgba haze="0.15 0.25 0.35 1"/>
    <global azimuth="150" elevation="-20"/>
  </visual>
  <visual>
    <rgba com="0.502 1.0 0 0.5" contactforce="0.98 0.4 0.4 1" contactpoint="1.0 1.0 0.6 0.4"/>
    <scale com="1" forcewidth="0.03" contactwidth="0.01" contactheight="0.02" framewidth="0.05" framelength="0.6"/>
    <map force="0.005"/>
  </visual>
  <asset>
    <!-- skybox removed: defined in the robot model XML to avoid duplicate-name error -->
    <texture type="2d" name="groundplane" builtin="checker" mark="edge" rgb1="0.2 0.3 0.4" rgb2="0.1 0.2 0.3" markrgb="0.8 0.8 0.8" width="1000" height="1000"/>
    <material name="groundplane" texture="groundplane" texuniform="true" texrepeat="5 5" reflectance="0.2"/>
  </asset>

  <worldbody>
    <light pos="0 0 10" dir="0 0 -1" directional="true"/>
    <geom name="floor" size="0 3 .125" type="plane" material="groundplane" conaffinity="7" condim="3" friction="1"/>
  </worldbody>
</mujoco>