Hello, I'm wondering what the <gazebo reference=""> tag actually does? Is there a difference between writing stuff directly into a URDF file and writing it into a <gazebo reference=""> tag?
E.g. I can set mue for a link as follows:
<contact_coefficient mu="100000" resitution="0" k_p="0" k_d="100" />
But also via the tag
<gazebo reference="link">
<mu1>1e10</mu1>
<mu2>1e10</mu2>
</gazebo>
What's the difference?