Support config files from LCM

[patmarion]

I thought that Director had a mode to listen for PARAM_UPDATE channel, but I'm not sure how to make that work. I only know how to pass -c <file.cfg> on the command line.

Director should be able to:

• [x] receive urdf model from ROBOT_MODEL channel
• [ ] receive bot config from PARAM_UPDATE
• [ ] receive director_config.json from lcm channel to be determined

Other questions:

Should director_config.json specify the .cfg file, or do we keep those separate command line options? Since director_config.json specifies the fp.mat and .urdf files. Is there a use case for loading different .cfg files?

What about hand urdf files? Those are still read from disk. The main use case here is the ability to playback old logs, we don't necessarily need to support new plan queries while playing old logs.

Should we support reloading bot config and director_config.json at any point in time, or just have the application block on startup until the LCM message is received (which is how PARAM_UPDATE usually behaves, whereas ROBOT_MODEL supports reloading)

[mauricefallon]

the second issue above would be in more agreement with other modules. I don't have an opinion on the 3rd.

We do have use cases for cfgs different from the json: For example we would need different json files for MIT and Edinburgh Valkyries if we put the cfg in the json. Also sometimes want to process logs with old sensor configs.

Yes, hand urdfs are still read from disk.

While reloading the bot config has been used in the system (notably in state-sync), it hasn't been wide spread.

[patmarion]

By the way, I figured out that if you use quotes to specify an empty cfg filename then Director correctly waits for the PARAM_UPDATE lcm message to get bot param settings from a log instead of reading from a file. This is required in order to get the correct config when replaying logs from the DRC finals era.

director --atlas_v5 -c ""