mujoco

<!-- Copyright 2026 DeepMind Technologies Limited

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at

         http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     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>
  <include file="scene.xml"/>

  <option cone="elliptic" solver="CG" />

  <default>
    <default class="gripper">
      <geom type="box" size="0.02 0.15 0.02" rgba="0.5 0.5 0.5 1"
            solref="0.001 1" friction="2 0.1 0.1"/>
      <joint type="slide" axis="0 0 1" range="-1 1"/>
      <default class="finger">
        <geom size="0.01 0.06 0.03"/>
        <joint type="slide" range="0 0.1"/>
      </default>
    </default>
  </default>

  <worldbody>
    <body name="gripper_solid" pos="0.2 0.45 0.2">
      <joint name="lift_solid" class="gripper"/>
      <geom class="gripper"/>
      <body name="left_finger_r" pos="0.05 -0.1 0" childclass="finger">
        <joint name="left_slide_r" axis="0 1 0"/>
        <geom rgba="0.8 0.2 0.2 1"/>
      </body>
      <body name="right_finger_r" pos="0.05 0.1 0" childclass="finger">
        <joint name="right_slide_r" axis="0 -1 0"/>
        <geom rgba="0.8 0.2 0.2 1"/>
      </body>
    </body>

    <body name="gripper_hollow" pos="0.2 0 0.2">
      <joint name="lift_hollow" class="gripper"/>
      <geom class="gripper"/>
      <body name="left_finger_s" pos="0.05 -0.1 0" childclass="finger">
        <joint name="left_slide_s" axis="0 1 0"/>
        <geom rgba="0.2 0.8 0.2 1"/>
      </body>
      <body name="right_finger_s" pos="0.05 0.1 0" childclass="finger">
        <joint name="right_slide_s" axis="0 -1 0"/>
        <geom rgba="0.2 0.8 0.2 1"/>
      </body>
    </body>

    <body name="solid" pos=".32 0 .2">
      <flexcomp
        origin="0 0 0" count="8 2 12" cellcount="6 1 6"
        type="grid" name="soft_mesh" dim="3" spacing=".025 .05 .025"
        mass="0.43" radius="0.005" dof="trilinear" rgba="0.7 0.9 0.7 1">
        <edge equality="strain" solref="0.001 1"/>
        <contact selfcollide="none"
              internal="false"
              friction="2.0 0.5 0.01"
              solref="0.001 1"
              solimp="0.99 0.999 0.001"/>
      </flexcomp>
    </body>

    <body name="hollow" pos=".32 .45 .2">
      <flexcomp
        origin="0 0 0" count="8 2 12" cellcount="6 1 6"
        type="grid" name="soft_mesh_2" dim="3" spacing=".025 .05 .025"
        mass="0.43" radius="0.005" dof="trilinear" rgba="0.9 0.7 0.7 1">
        <elasticity young="1e4" poisson="0.3" damping="0" elastic2d="bend" thickness="0.02"/>
        <edge equality="strain" solref="0.001 1" solimp="0.99 0.999 0.001"/>
        <contact selfcollide="none"
              internal="false"
              friction="2.0 0.5 0.01"
              solref="0.001 1"
              solimp="0.99 0.999 0.001"/>
      </flexcomp>
    </body>
  </worldbody>

  <equality>
    <joint joint1="right_slide_r" joint2="left_slide_r"/>
    <joint joint1="right_slide_s" joint2="left_slide_s"/>
  </equality>

  <actuator>
    <position name="lift_r" joint="lift_solid" kp="400" dampratio="1" ctrlrange="-1 1"/>
    <position name="grasp_r" joint="left_slide_r" kp="10" dampratio="1" ctrlrange="0 5"/>

    <position name="lift_s" joint="lift_hollow" kp="400" dampratio="1" ctrlrange="-1 1"/>
    <position name="grasp_s" joint="left_slide_s" kp="10" dampratio="1" ctrlrange="0 5"/>
  </actuator>
</mujoco>