mujoco

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     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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     See the License for the specific language governing permissions and
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-->

<mujoco model="Drape">
  <include file="scene.xml"/>

  <!-- Three cloths dropped over a sphere. All contacts are passive (cloth-cloth, self, and
       cloth-vs-static sphere) with stiffness carried implicitly by the effective metric. -->

  <!-- The metric solve for qacc_smooth is iterative and its blocks do not see the vertex-to-vertex
       coupling that contact introduces, so a contact-rich scene like this one needs a larger
       iteration budget than the default to converge it. -->
  <option timestep="0.002" solver="CG" tolerance="1e-6" iterations="400" integrator="implicitfast"/>

  <size memory="50M"/>

  <worldbody>
    <geom name="ball" type="sphere" size=".3" pos="0 0 .3" rgba=".45 .45 .5 1"/>

    <flexcomp type="grid" count="13 13 1" spacing=".055 .055 .055" pos="0 0 .68"
              radius=".004" mass=".25" name="cloth1" dim="2" rgba=".85 .35 .25 1">
      <contact selfcollide="auto" passive="true" solref="0.01 1" solimp=".95 .99 .0001"/>
      <elasticity young="2e4" poisson=".2" thickness="1e-3" elastic2d="both" damping="1e-2"/>
    </flexcomp>

    <flexcomp type="grid" count="13 13 1" spacing=".055 .055 .055" pos=".06 -.04 .78"
              radius=".004" mass=".25" name="cloth2" dim="2" rgba=".25 .55 .8 1">
      <contact selfcollide="auto" passive="true" solref="0.01 1" solimp=".95 .99 .0001"/>
      <elasticity young="2e4" poisson=".2" thickness="1e-3" elastic2d="both" damping="1e-2"/>
    </flexcomp>

    <flexcomp type="grid" count="13 13 1" spacing=".055 .055 .055" pos="-.05 .05 .88"
              radius=".004" mass=".25" name="cloth3" dim="2" rgba=".95 .8 .3 1">
      <contact selfcollide="auto" passive="true" solref="0.01 1" solimp=".95 .99 .0001"/>
      <elasticity young="2e4" poisson=".2" thickness="1e-3" elastic2d="both" damping="1e-2"/>
    </flexcomp>
  </worldbody>
</mujoco>