Convert between coordinate systems in messages? about rosintegration HOT 2 OPEN

Hi!

That's a very interesting point that also hit me when building ROSIntegrationVision. There, i directly included the conversion while publishing tf. In that case, it's necessary to convert the coordinates between the tf tree has to be constructed properly.
For general Vectors and Quaternions i would be a bit more defensive, as people might use Vectors for all kinds of stuff, and not always to explicity describe an (absolute) location in the world. I'm also with you on your con "might lead to confusion about what the messages do in the background".

I would propose that one should be able to supply a flag for every instantiation of a message/service which enables the conversion everytime a message is processed (given, the message/service handles coordinates).
What do you (and others looking here) think of that?

from rosintegration.

A flag for the messages/services sounds like a good idea, then it can also be backward compatible. The problem might be, that that flag needs to be implemented in at least all messages that use Vector3 and Quaternion and be passed down. Seems to me like a lot has to be changed for that to work. Also, how does the topic know into what coordinate system it should interpret the incoming messages?

Maybe another option would be to have a flag in the topics, passed down to the converters which make sure that they convert incoming messages from the ROS-side to Unreal coordinates and vice versa. That would still need a lot of changes though.

from rosintegration.