Some problem about the Unitydemo/carDemo

[MiaoMiaoMeng]

AirSim/Unity/UnityDemo/Assets/AirSimAssets/Scripts/Vehicles/VehicleCompanion.cs

Line 197 in 68ae8de

private static bool SetDistortionParam(string cameraName, string paramName, float value, string vehicleName) {

Hi, I have some question about this function, It seem like we didn't use this function.
So I try to annotation this part of code.
But when I try to run the carDemo, the Editor will crash.
From the Log i found

Loaded scene 'Assets/Scenes/CarDemo.unity'
Deserialize: 27.018 ms
Integration: 13.212 ms
Integration of assets: 1.326 ms
Thread Wait Time: 6.267 ms
Total Operation Time: 47.824 ms
NullReferenceException: Object reference not set to an instance of an object
at AirSimUnity.VehicleCompanion.Reset (System.String vehicleName) [0x00025] in C:\AirSim-master\Unity\UnityDemo\Assets\AirSimAssets\Scripts\Vehicles\VehicleCompanion.cs:146

AirSim/Unity/UnityDemo/Assets/AirSimAssets/Scripts/Vehicles/VehicleCompanion.cs

Line 146 in 68ae8de

vehicle.VehicleInterface.ResetVehicle();

But I didn't found which code use it, except “getfunctionpointerfordelegate”.

Is there anyone else have the same situation like me？

[ahmed-elsaharti]

Hi @MiaoMiaoMeng , it looks like this was added as a placeholder for camera distortion in e5967a0 of #3039

[MiaoMiaoMeng]

Thx for your help@ahmed-elsaharti,
I read the part of code in e5967a0, but in this part:

    private static bool SetDistortionParam(string cameraName, string paramName, float value, string vehicleName) {
        var vehicle = Vehicles.Find(element => element.vehicleName == vehicleName);
        return vehicle.VehicleInterface.SetDistortionParam(cameraName, fov_degrees);
    }

the value which named as fov_degrees is not found. I think that is the 'value'
So I try to rename float 'value' to fov_degrees, but i didn't found the override function with two param.

BTW,I also didn‘t found any reference about this function.

[MiaoMiaoMeng]

Hi @MiaoMiaoMeng , it looks like this was added as a placeholder for camera distortion in e5967a0 of #3039

I read the src in this morning and set a try catch in Reset() function, from the result I think that Vehicles can't Find the element with 'vehicleName'

    private static bool Reset(string vehicleName)
            {
                try
                {
                    var vehicle = Vehicles.Find(element => element.vehicleName == vehicleName);
                    vehicle.VehicleInterface.ResetVehicle();
                }
                catch (Exception e) {
                    Debug.Log("vehicle is null");
                    throw e;
                }
                return true;
            }

that's make me feel confuse, I think the vehicleName is already pass in InitDelegators() when the StartVehicleServer() been used.
So I can't find the reason why it has a NullReference in Reset() function.

[ahmed-elsaharti]

Thx for your help@ahmed-elsaharti,
I read the part of code in e5967a0, but in this part:

    private static bool SetDistortionParam(string cameraName, string paramName, float value, string vehicleName) {
        var vehicle = Vehicles.Find(element => element.vehicleName == vehicleName);
        return vehicle.VehicleInterface.SetDistortionParam(cameraName, fov_degrees);
    }

the value which named as fov_degrees is not found. I think that is the 'value'
So I try to rename float 'value' to fov_degrees, but i didn't found the override function with two param.

BTW,I also didn‘t found any reference about this function.

My understanding is that camera distortion hasn't been implemented in Unity yet. I could be wrong though since I barely looked into the code within the PR. @saihv would probably be able to answer this better than me.

[jonyMarino]

Yes, that is correct; the programmable camera distortion was not implemented for Unity.

[JW-Kwon35]

Hi @MiaoMiaoMeng,
so how did u build the system? I tried to comment out the SetDistortionParam function and the build process seemed quite ok until Unity said "Problem in starting AirSim server".

[kengregson]

Encountered same, last working Unity version I found can be checked out via:
'git checkout 7f48ba3'

Unity build is currently broken, @jonyMarino maybe this is more than a feature request?
Attached screen snap of errors in Editor that prevent running either Car or Drone Mode of demo.

[david9705]

Hello, @MiaoMiaoMeng .
I also encounter same problem.
Unity build is currently broken when annotate the SetDistortionParam function, but without annotation Unity report 'IVehicleInterface' does not contain a definition for 'SetDistortionParam' and no accessible extension method 'SetDistortionParam' (same as @kengregson picture)

How do you solve those errors?

[MiaoMiaoMeng]

Hi @MiaoMiaoMeng,
so how did u build the system? I tried to comment out the SetDistortionParam function and the build process seemed quite ok until Unity said "Problem in starting AirSim server".

Hi @MultiPsy,
I have not successfully built this system, as I said there is a null reference in Reset() function.
And for now, I didn't spend time on it. Because I need to deal with the transplantation of a slam system.
So if I have time after, I will find out how to avoid this problem.

[zimmy87]

Hi @MiaoMiaoMeng and @MultiPsy, thank you for reporting and testing this issue. I just created a PR that should address both issues you are experiencing with the UnityDemo. Please apply this PR and test again and let me know if you are still seeing this issue.

[MiaoMiaoMeng]

Hi @MiaoMiaoMeng and @MultiPsy, thank you for reporting and testing this issue. I just created a PR that should address both issues you are experiencing with the UnityDemo. Please apply this PR and test again and let me know if you are still seeing this issue.

Thanks @zimmy87 ,

It works well.
I will close the issue.

Thank you again.

[kengregson]

@zimmy87, please accept my thanks as well!
Also verified under Ubuntu 20.04/Unity 2019.3.12f1 with PX4-SITL/QGroundControl.

Note: Issue #1617 still seems to prevent proper operation of PX4 SITL unless settings.json and VehicleCompanion.cs are modified as described in the workaround.