Support for multiple drones in Unity

[ykeuter]

Using multiple vehicles is not yet supported in Unity ( #1540 ). This PR attempts to add this functionality.

A few things to note:

• This PR mainly focusses on drones, but the changes should cover most part for car simulations too.
• There is a test scene MultiDroneDemo which can be used with multi_agent_drone.py.
• The vehicles in the scene should be named according to the names in settings.json.
• Vehicle coordinates in settings.json are ignored (as is already the case with a single vehicle).
• The new scripts AirSimServer and AirSimTick depend on a correct setting of the script execution order.
• Issues Execution order of simulation loop for drone in Unity #3126 and Update render functions called twice per tick #3127 are related to parts of the code changes.
• Code changes were made with minimal overall impact in mind (this is not a refactoring).

[ghost]

All CLA requirements met.

[zimmy87]

It seems that you have a lot of conflicts. This is most likely due to conflicts with autoformatted code in master. Please follow these steps to resolve this:

1. check out your pull request
2. run git checkout master .clang-format in your repo's root folder
3. if you don't have npm installed, download it from https://www.npmjs.com/get-npm
4. run npm install -g clang-format
5. run clang-format -i path/to/file for each conflicting file
6. run git add -u to track all style changes
7. run git commit -am "apply style from clang-format"
8. run git merge master
9. resolve other non-style conflicts if you have any
10. push changes

Thanks for helping us with these style changes!

[jonyMarino]

Hi @ykeuter! Thank you for applying the clang-format. It seems that there are more conflicts in your PR. If you can solve them, we are ready to test this and merge it. Thanks!

[ykeuter]

Hi @jonyMarino ! Thanks for your message. It's been a long time since I worked on this code. I just tried to apply the clang format, but indeed saw there are still conflicts. I will need time to get back into the project. No guarantee on my schedule, but I will keep you posted.

[ykeuter]

Hi @jonyMarino ! The merge conflicts are resolved now. I was able to run the MultiDroneDemo scene and everything seems to be working. Please have a look and let me know if there are any more issues / questions. Cheers. Yvo

[jonyMarino]

Thanks, Yvo! We will start testing this!

[zimmy87]

Tested with hello_drone.py and multi_agent_drone.py scripts, which both worked as expected. Looks good apart from minor style comments.

[ykeuter]

Hi @zimmy87! Thanks for the review and merging this PR. Much appreciated!

[SworterW]

Using multiple vehicles is not yet supported in Unity ( #1540 ). This PR attempts to add this functionality.

A few things to note:

• This PR mainly focusses on drones, but the changes should cover most part for car simulations too.
• There is a test scene MultiDroneDemo which can be used with multi_agent_drone.py.
• The vehicles in the scene should be named according to the names in settings.json.
• Vehicle coordinates in settings.json are ignored (as is already the case with a single vehicle).
• The new scripts AirSimServer and AirSimTick depend on a correct setting of the script execution order.
• Issues Execution order of simulation loop for drone in Unity #3126 and Update render functions called twice per tick #3127 are related to parts of the code changes.
• Code changes were made with minimal overall impact in mind (this is not a refactoring).

Hi @ykeuter I try to play MultiDroneDemo, but it always make my unity crashed like #4764. whatever the latest airsim version, or this merge version. I also alter my settings.json like https://github.com/microsoft/AirSim/blob/main/PythonClient/multirotor/multi_agent_drone.py .Could you please tell me how can you play the MultiDroneDemo as normal, what the steps. Thanks so much !

[ykeuter]

Hi @ykeuter I try to play MultiDroneDemo, but it always make my unity crashed like #4764. whatever the latest airsim version, or this merge version. I also alter my settings.json like https://github.com/microsoft/AirSim/blob/main/PythonClient/multirotor/multi_agent_drone.py .Could you please tell me how can you play the MultiDroneDemo as normal, what the steps. Thanks so much !

Hi @SworterW ! Thanks for your message. It has been an awful long time since I looked at this. I do remember that the following point is really important:

• The vehicles in the scene should be named according to the names in settings.json.

Apart from that I do not know if subsequent commits / changes to the code base have broken the multi-drone version. At a later stage I might look back into this.

[SworterW]

Hi @ykeuter I try to play MultiDroneDemo, but it always make my unity crashed like #4764. whatever the latest airsim version, or this merge version. I also alter my settings.json like https://github.com/microsoft/AirSim/blob/main/PythonClient/multirotor/multi_agent_drone.py .Could you please tell me how can you play the MultiDroneDemo as normal, what the steps. Thanks so much !

Hi @SworterW ! Thanks for your message. It has been an awful long time since I looked at this. I do remember that the following point is really important:

• The vehicles in the scene should be named according to the names in settings.json.

Apart from that I do not know if subsequent commits / changes to the code base have broken the multi-drone version. At a later stage I might look back into this.

Hi @ykeuter ! Thank you for your reply. I find my defalt setting in names of vehicles in the scene is the same as my settings.json.

I even chang the gameobject's name to be the same like

My unity was crashed too.
I try to review the changes one by one, and i find it's not different with my version.

Honestly, i have no clue now. If it's convenient for you, could you please send a version that you play multidrone successfully. Then i will have a new test. Thanks so much!!

[ykeuter]

Hi @SworterW ! That is really strange. I was able to install everything from scratch and run MultiDroneDemo. The only thing I needed to change was the settings.json, but yours seems to be correct. Could you check if you have a stale (single drone) settings.json hanging around somewhere? I remember AirSim checks at multiple locations for this file and could pick up the wrong one. I put mine in My Documents\AirSim\settings.json.

[SworterW]

Hi @SworterW ! That is really strange. I was able to install everything from scratch and run MultiDroneDemo. The only thing I needed to change was the settings.json, but yours seems to be correct. Could you check if you have a stale (single drone) settings.json hanging around somewhere? I remember AirSim checks at multiple locations for this file and could pick up the wrong one. I put mine in My Documents\AirSim\settings.json.

Hi @ykeuter ! Your reply inspired me a lot. When i built airsim at the beginning, it would spawn setting.json at Document\AirSim\settings.json

I try a test. When i alter the vehicle name 'SimpleFlight' to 'Drone1' in DroneDemo, and alter the Document\AirSim\settings.json like
{
"SeeDocsAt": "https://github.com/Microsoft/AirSim/blob/master/docs/settings_json.md",
"SettingsVersion": 1.2,
"SimMode": "Multirotor",
"ClockSpeed": 1.0,
"Vehicles": {
"Drone1": {
"VehicleType": "SimpleFlight",
"DefaultVehicleState": "Armed",
"EnableCollisionPassthrogh": false,
"EnableCollisions": true,
"AllowAPIAlways": true,
"RC": {
"RemoteControlID": 0,
"AllowAPIWhenDisconnected": false
}
}
}
}
my unity crashed as i play MultidroneDemo. I realize that the Document\AirSim\settings.json is not work. So i search my computer.

I find two other settings.json in my computer.When i alter the vehicle name to 'Drone1' at all the settings.json, my unity crashes too. But when i alter the vehicle name back to 'SimpleFlight' in DroneDemo, it play as normal.
From the test, i find the three setting.json are not work. I don't know where is the correct file would AirSim pick up.Thank you for your patience！

[ykeuter]

@SworterW, you probably still have yet another settings file lying around somewhere. The issue is that the dll plugin looks at different locations than the Unity code itself does. I once made a PR to deal with this confusion by using an environment variable:
main...ykeuter:AirSim:settings-env-var
Maybe this points you into the right direction.

[SworterW]

@SworterW, you probably still have yet another settings file lying around somewhere. The issue is that the dll plugin looks at different locations than the Unity code itself does. I once made a PR to deal with this confusion by using an environment variable: main...ykeuter:AirSim:settings-env-var Maybe this points you into the right direction.

Hi @ykeuter ! I'm so sorry to bother you again. I tried this method main...ykeuter:AirSim:settings-env-var
In fact, I found that unity was reading my json files correctly, whether or not this environment variable was set.
I did another test, if my json(at Documents\AirSim\settings.json) is set like this, and the Vehicle Name in DroneDemo is SimpleFlight：

then when I play the scene named SimModeSelector, he will jump to DroneDemo correctly.It played as normal and my unity did not crash.
When my json(at Documents\AirSim\settings.json) set null like this:

it will not jump to DroneDemo, and output thelog:

So I guess airsim should read the correct json path, but there is an exception in the process of parsing. Thank you very much for your patient reply each time. Being able to run MultiDroneDemo in unity is very important to me. If possible, could you send me a project file that can successfully run MultiDroneDemo. My email is 2019020800217@jlxy.nju.edu.cn

[pankan2]

I also encountered the problem of modifying the json. I added the drone to the drone scene and modified the json file. Adding an additional drone directly at the point (0, 0, 0) is out of control. Did you solve this problem?

[sandilyasg]

@ykeuter @SworterW @zimmy87 Can you please give the steps you took to run the multi_agent_drone.py? I have my settings.json correctly set up, and in Unity I am running the "SimModeSelector" scene, after which I select "Drone" mode, but it crashes. What are the correct steps to setting this up?

[ykeuter]

Most of these issues still boil down to stale (auto-generated) settings.json files... Please check for any of those on your machine and take a look at main...ykeuter:AirSim:settings-env-var for some ways to get around this.

[SworterW]

@sandilyasg @pankan2
You can check out the additional settings.json generated on your system and change it to also support multiple drone configurations in your scenario