mujoco

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     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
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         http://www.apache.org/licenses/LICENSE-2.0

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     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->

<mujoco model="Hammock">
<!-- Degree of Freedom: 312
     Actuators: 21
     Equality constraints: 178
     Tendons: 178

     Simple humanoid on a hammock, implemented as a 2D grid composite, pinned at the corners.
-->

  <option timestep="0.001" solver="CG" iterations="30" tolerance="1e-6"/>

  <size memory="20M"/>

  <visual>
    <map force="0.1" zfar="30"/>
    <rgba haze="0.15 0.25 0.35 1"/>
    <quality shadowsize="2048"/>
    <global offwidth="800" offheight="800"/>
  </visual>

  <asset>
    <texture type="skybox" builtin="gradient" rgb1="0.3 0.5 0.7" rgb2="0 0 0" width="512" height="512"/>
    <texture name="plane" type="2d" builtin="checker" rgb1=".2 .3 .4" rgb2=".1 0.15 0.2"
             width="512" height="512" mark="cross" markrgb=".8 .8 .8"/>
    <texture name="hammock" type="2d" builtin="checker" rgb1=".1 .5 .1" rgb2=".5 .1 .1"
             width="512" height="512" mark="edge" markrgb=".8 .8 .8"/>
    <material name="plane" reflectance="0.3" texture="plane" texrepeat="1 1" texuniform="true"/>
    <material name="hammock" texture="hammock"/>
    <model name="humanoid" file="humanoid_body.xml"/>
  </asset>

  <worldbody>
    <geom name="floor" pos="0 0 -1" size="0 0 .25" type="plane" material="plane" condim="3"/>
    <light directional="true" diffuse=".2 .2 .2" specular="0 0 0" pos="0 0 5" dir="0 0 -1" castshadow="false"/>
    <light directional="false" diffuse=".8 .8 .8" specular="0.3 0.3 0.3" pos="0 0 4" dir="0 0 -1"/>
    <flexcomp name="hammock" type="grid" count="11 9 1" spacing="0.2 0.2 0.2" material="hammock"
              radius="0.04" dim="2">
      <pin id="0 8 90 98"/>
      <edge equality="true" damping="10" solimp=".95 .99"/>
      <contact selfcollide="none" internal="false" solimp=".99 .999 .00001"/>
    </flexcomp>
    <frame euler="0 180 0" pos="-.4 -.2 2">
      <attach model="humanoid" body="torso" prefix="humanoid_"/>
    </frame>
  </worldbody>

</mujoco>