There is still one file: ProjectVersion.txt, which changes based on the Unity version, but since that is similar to the .uproject file for Unreal, therefore didn't add that

Also, an extra settings.json file is getting created in the main directory if the settings.json in Documents/AirSim is not present, there's an open PR for this - #2303, though I haven't tested it

The RPC CMake file in Unity is modified from the rpclib's CMakeLists.txt, which has the same error, and has been fixed in the fork which is used in #2340

Edit: Attached is the output in the current form of the branch, captured using
./build.sh &> output.txt
I suspect compiler flags from a different build such as from LLVM are also being applied
output.txt

Looks good to me but haven't tested it. @madratman - please feel free to merge this.

@sytelus Thanks for the review! I've tested this on Ubuntu 18.04 with the latest version of Unity available (2019.2.17f1)

There are two .asset files which were generated by Unity, along with a settings.json in the root directory if the settings.json in Documents/AirSim is not present, and modification of ProjectVersion.txt.
These were out of the scope of this, and so am not adding them. The creation of settings.json is a bug which needs to be fixed

there's a commit for a sharedlib in there (Unity/UnityDemo/Assets/Plugins/libAirsimWrapper.so.meta).
Why is that needed?

@madratman This was the part I was confused about, there's already a .meta file for the DLL generated on Windows, so either that can be removed or following the logic, on Linux, the .so file is generated with it's associated .meta file, which is being added
Not sure which one is correct, I don't have Unity setup on Windows currently so can't test that right now, but I think removing the .dll.meta file instead of adding the .so.meta file should also work
In that case, the entire folder can be put into .gitignore

Hmmm, my guess is the commit-ment of the .dll.meta was a human error. Not 100% sure atm. Will get back to you.

Rebased on master, as can be seen (or not seen), the Travis PR build is not appearing

If the problem still persists, an option could be to update the Unity version in docs and the project files in PR

On Windows, running Unity 2019.2.17f1 I get 100s of logs in the unity console log:

Control Mode:  Keyboard Vehicle=PhysXCar
UnityEngine.Debug:Log(Object)

When I try and run hello_car.py and running the Unity demo, it can connect, however the car doesn't move.

This PR currently just fixes compilation errors, some annoyances and the crash on starting
Further changes would probably need follow-up PR, contributions would definitely be very much welcome

I think several people have been using this PR for Unity, and it seems to work atleast for not crashing at the beginning itself
If the problem with the older one still persists, then maybe the docs could be updated to use the later version on Linux

I am able to run this fine in Unity 2019.3.12 in Ubuntu (seemingly released yesterday). No compilation errors - but I do see the barrage of warnings with all sorts of obscure compiler flags; I cannot seem to find the origin of these through grep.

EDIT: Found the cause, discussion in #2478

Looks like Unity Hub for Ubuntu is also new? (The AirSim instructions don't mention it). Perhaps we should upgrade the Unity assets to target 2019.3 and merge.

Thanks @saihv! I think let's update the assets, and merge it.
And also update the links in doc

Interestingly

{
  "SettingsVersion": 1.2,
  "SimMode": "Multirotor",
   "Vehicles": {
      "Drone1": {
          "VehicleType": "simpleflight"
          }
      }
  }

results in crash

but

{
  "SettingsVersion": 1.2,
  "SimMode": "Multirotor"
}

works

Maybe this is the issue I was running in to.

Thanks a lot for testing and merging @saihv @madratman
Regarding the settings, there does seem to quite a lot of issues with them with Unity, such as Simmode not being changed, etc.
There is a PR open which maybe fixes these issues, #2303, I haven't tested it myself

On windows i run unity Demo on 2019.3.12f,use keyboard the car can movie ,but when i run the hello_car.py,it connect ,no error ,normal output:speed,Go forward,steer right~~~~~,the car in the scene doesn't move. i really want to know how to solve it. when i use 2018.2.15,it didn't occur thank you!