Dear altruist. I have got urdf, srdf, and mesh files of a robot. I am trying to do some simulation of the model for learning. I tried to follow these two tutorials 1. 2.

I tried with my urdf file in place of tutorials one, but in rviz I cant see any parts of my robot and also showing errors of "No transform from [] to []"

Do I need any joits launch file that I dont have? Please guide me through this if you can.