Get traffic information

[Santisoutoo]

Hi eveyone,
I am building a tower controller agent but i am having problems with getting data with traf variable.

from bluesky import traf

def traffic(self):
    retry_count = 0
    while traf is None and retry_count < 5:
        print("'traf' object is not available yet. Retrying in 2 seconds...")
        time.sleep(2)
            retry_count += 1
    if traf is None:
        print("Could not initialize 'traf' after several attempts.")
        return
    for i in range(traf.ntraf):
        callsign = traf.id[i]
    ...

When I run the simulator and create some airplanes, traf remains None. I can see the airplanes in the simulator’s GUI and even get their info via the POS command, but my agent doesn't seem to pick up any traffic data through traf.

Is this import method correct, or is there something I need to adjust in the initialization or configuration of BlueSky to ensure that traf is properly populated? Has anyone experienced a similar issue or found a workaround for accessing traffic data in a shared process?

I also ensured that the simulation was running and the execution mode was render.

Any help would be greatly appreciated. Thanks!

[jooste]

Hi @Santisoutoo,

The problem you are encountering is that on first import, no objects within bluesky are initialised yet, so when you do from bluesky import traf, all you get is None. The way to avoid this is by importing the module instead of only specific objects from the module:

import bluesky as bs

def traffic(self):
    for i in range(bs.traf.ntraf):
        callsign = traf.id[i]
    ...

Note that this approach is not necessary in plugins, as these are only imported after bluesky is initialised, so by then all simulation objects exist.

[Santisoutoo]

Thanks for your response, @jooste.
I was trying to build a FastAPI server to apply some of the concepts I've learned at university for this proyect and I did not take into account that.
I think the approach of using a plugin is much easier for communicating with the sim. Thank you!