http://wiki.ros.org/usv_gazebo_plugins

It was confirmed that the parameters in the link above are the variables applied to the dynamic equation of USV. In order for these variables to enter the dynamics equation, there must be content that is substituted into the equation for them.

https://github.com/osrf/vrx/blob/gazebo_classic/usv_gazebo_plugins/src/usv_gazebo_dynamics_plugin.cc

In addition to the variables written in that plug-in, there are variables and link-related things. I wonder if it is correct that the parameters written in the urdf.xacro and plugin.xacro files go into the cc file above and are applied.