Defined box gazebo material

urdf/sensors.xacro

@@ -32,6 +32,10 @@
       </collision>
     </link>
     
+    <gazebo reference="${name}_box">
+      <material>Gazebo/Black</material>
+    </gazebo>
+    
     <joint name="joint_${parent}_to_${name}_box" type="fixed" >
       <parent link="${parent}"/>
       <child link="${name}_box"/>