We use Xacro formatted description, which is simpler and cleaner than URDF format. The test environment is: Ubuntu 16.04 + ROS Kinetic.
cd ~/path-to-catkin-workspacecatkin_make
cd ~/path-to-catkin-workspace/src/laikago_rviz/launchroslaunch ./rviz.launchOr you can just run:roslaunch laikago_rviz rviz.launch
The robot should be spawned in Rviz.