In URDF texture tag, how exactly is the image used? (ROS iron, moveit2, rviz)

Question

https://wiki.ros.org/urdf/XML/link#Elements only says

<texture> (optional)
  The texture of a material is specified by a filename

How exactly does that work? How is the specified image used? How is it scaled? I am trying to use this with an URDF that I load with MoveIt2 and then display in RViz using the Motion Planning plug-in, and as far as I can tell, I only see some weird tiny fragment of the specified image... Or maybe not even that - I am having trouble even figuring out how what is displayed relates to the image (there is definitely some similarity between the image and what it displayed, but it's not something obvious to me)...

I am seeing a lot of Gazebo-specific discussions, but nothing for the generic URDF texture tag...

Answer 1

I will point you towards this thread, which discusses adding a texture to a link. It seems like you have to define your own material, which includes the image as well as the scale.

My best guess as to what is going on here is that URDF is not natively capable of scaling and wrapping any image around a link - which makes sense to me because URDF simply describes a robot's general appearance and functionality. When you want additional visual information to be displayed on a link, it is often better to use a file type that conveys both the mesh as well as the texture information - something like DAE/OBJ.

Take a look at how Doosan defines its description package using Collada files if you need some reference.