Compilation error in latest release

[songxiaocheng]

The Blocks project in AirSim v1.3.0 have compilation errors with UE 4.18:

1><path-ro-airsim>\Unreal\Environments\Blocks\Plugins\AirSim\Source\WorldSimApi.cpp(211): error C2660: 'DrawDebugString': function does not take 8 arguments
1>C:\Program Files\Epic Games\UE_4.18\Engine\Source\Runtime\Engine\Public\DrawDebugHelpers.h(47): note: see declaration of 'DrawDebugString'
1><path-ro-airsim>\Unreal\Environments\Blocks\Plugins\AirSim\Source\WorldSimApi.cpp(230): error C2660: 'DrawDebugString': function does not take 8 arguments
1>C:\Program Files\Epic Games\UE_4.18\Engine\Source\Runtime\Engine\Public\DrawDebugHelpers.h(47): note: see declaration of 'DrawDebugString'

AirSim/Unreal/Plugins/AirSim/Source/WorldSimApi.cpp

Line 211 in 03d239b

DrawDebugString(simmode_->GetWorld(), simmode_->getGlobalNedTransform().fromGlobalNed(positions[idx]), FString(strings[idx].c_str()), NULL, color.ToFColor(true), duration, false, scale);

AirSim/Unreal/Plugins/AirSim/Source/WorldSimApi.cpp

Line 230 in 03d239b

DrawDebugString(simmode_->GetWorld(), simmode_->getGlobalNedTransform().fromGlobalNed(poses[idx]).GetLocation(), FString(names[idx].c_str()), NULL, color.ToFColor(true), duration, false, text_scale);

It is because DrawDebugString in UE 4.18 was declared to have only 7 arguments. The last argument is missing. This is fixed by UE later (it seems form UE 4.20, see this commit). However, the "empty versions" of this function still not changed but it seems irrelevant to this Airsim issue (I am not familiar with UE's implementation but there is a UE issue mentioned this, see here).

But the Airsim documentation still recommends UE 4.18. I think systematically upgrading UE to newer versions is a good way to fix this problem. Temporarily, I have to delete the last argument of DrawDebugString in WorldSimApi.cpp.

[rajat2004]

Yes, the documentation needs to be updated. I believe from this release AirSim will require UE>=4.22 (or maybe even 4.24). Some more PRs in the line (#2482, #2472) will require the newer UE versions

[madratman]

Updated the docs https://microsoft.github.io/AirSim/build_windows/
Current master works on UE>=4.22, but we do recommend 4.24.