https://wiki.ros.org/urdf/Tutorials/Building%20a%20Visual%20Robot%20Model%20with%20URDF%20from%20Scratch
urdf/Tutorials/Building a Visual Robot Model with URDF from Scratch - ROS Wiki
building afrom scratchurdftutorialsvisual
https://au.mathworks.com/help/robotics/ref/urdfexporter.html
urdfExporter - Create URDF exporter object from rigid body tree robot model - MATLAB
Use urdfExporter object to generate a unified robot description format (URDF) file from the rigidBodyTree object.
createurdfexporterobjectrigid
https://ftp.udx.icscoe.jp/ros/ros_wiki_mirror/hector_quadrotor_urdf.html?distro=groovy
hector_quadrotor_urdf
hectorquadrotorurdf