My question is what are the rules for naming topics?
that would be these: wiki/Names.
Quoting the relevant part:
Valid Names
A valid name has the following characteristics:
- First character is an alpha character ([a-z|A-Z]), tilde (
~) or forward slash (/) - Subsequent characters can be alphanumeric ([0-9|a-z|A-Z]), underscores (
_), or forward slashes (/)
''Exception'': base names (described below) cannot have forward slashes (/) or tildes (~) in them.
So - (dashes) are not legal.
however I'm not entirely convinced the problem you ran into is related to this.
Model.cc exception occurred in the Load function
this reads like an error directly from Gazebo, so I would suggest to post this on Gazebo Answers instead of here on ROS Answers.
If you do post there:
- please post a link here in a comment so we can keep things connected
- include the SDF and/or URDF that you tried to load in your question, as otherwise people on that forum will not be able to help you (they cannot 'see' what you see)
please always link to any tutorials you are following or pages you refer to. We don't know what you are doing otherwise.
Additionally: the question title is "Interesting problem with naming topic" right now, which is not very descriptive. You appear to have a very clear symptom, so it would be good to use that as a title (ie: "Gazebo 'load function' exception with dash in model name" or something like that).