Clean up MJCF files

Author: JeanElsner

src/dm_robotics/panda/assets/panda/panda.xml

@@ -9,8 +9,6 @@
     <mesh name="link5" file="link5.obj" />
     <mesh name="link6" file="link6.obj" />
     <mesh name="link7" file="link7.obj" />
-    <mesh name="hand" file="hand.obj" />
-    <mesh name="finger" file="finger.obj" />
     <texture name="panda" file="panda.png" type="2d" />
     <material name="panda" texture="panda" shininess=".4" specular=".4" />
     <material name="panda_white" rgba="1 1 1 1" shininess="0.4" specular="0.4" />

src/dm_robotics/panda/assets/panda/panda_hand.xml

@@ -1,19 +1,10 @@
 <mujoco model="panda_hand">
   <compiler angle="radian" />
   <asset>
-    <mesh name="link0" file="link0.obj" />
-    <mesh name="link1" file="link1.obj" />
-    <mesh name="link2" file="link2.obj" />
-    <mesh name="link3" file="link3.obj" />
-    <mesh name="link4" file="link4.obj" />
-    <mesh name="link5" file="link5.obj" />
-    <mesh name="link6" file="link6.obj" />
-    <mesh name="link7" file="link7.obj" />
     <mesh name="hand" file="hand.obj" />
     <mesh name="finger" file="finger.obj" />
     <texture name="panda" file="panda.png" type="2d" />
     <material name="panda" texture="panda" shininess=".4" specular=".4" />
-    <material name="panda_white" rgba="1 1 1 1" shininess="0.4" specular="0.4" />
   </asset>
   <equality>
     <joint name="couple_fingers" joint1="panda_finger_joint1" joint2="panda_finger_joint2" solimp="0.95 0.99 0.001" solref="0.005 1"/>