Building Carla on Mac OSX

[ajax98]

Online I see that there only exist manual for installing and building Carla on Linux. Is it possible for installing and running it on Mac?

[nsubiron]

Hi @ajax98,

Yes, it is possible. However we don't have an automated build system for MacOS, so it would require some effort to make it work.

Please have a look at the progress at #103. Also it might be helpful to check out the documentation for How to build on Linux and the discussion for building on Windows at #21 as the process is basically the same.

Please share your progress here if you find any difficulties. It can be very helpful for other people trying to build on Mac, and eventually we might be able to make an automated system as for Linux.

---

There is a compilation error that is going to appear, you need to replace the block at "Source/Carla/SceneCaptureCamera.cpp" Line 27 by

static constexpr auto DEPTH_MAT_PATH =
#if PLATFORM_LINUX
    TEXT("Material'/Carla/PostProcessingMaterials/DepthEffectMaterial_GLSL.DepthEffectMaterial_GLSL'");
#else
    TEXT("Material'/Carla/PostProcessingMaterials/DepthEffectMaterial.DepthEffectMaterial'");
#endif

This is something we have to fix, but we'll have to test if the default depth material is working well on Mac. Help on this would be appreciated as we don't have here Mac machines to test it.

[nsubiron]

Check out #176 (comment)

[thegleb]

I skimmed the couple threads I've seen here about running Carla on a Mac and I have modified all the files as mentioned, but I keep running into the same issue. The .ueproject seems to get generated but I'm missing a couple of .dylibs, e.g. UE4Editor-Carla.dylib and a second one. Any advice?

Output from xcode when trying to build the CarlaUE4 project:

Undefined symbols for architecture x86_64:
  "FRHICommandListBase::WaitForRHIThreadTasks()", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
  "_GRHICommandList", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
      ASceneCaptureCamera::WritePixels(float) const in Module.Carla.cpp.o
  "FRHICommandListBase::WaitForDispatch()", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
  "FRHICommandListExecutor::ExecuteList(FRHICommandListImmediate&)", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
  "FlushRenderingCommands()", referenced from:
      FServerGameController::Tick(float) in Module.Carla.cpp.o
  "_GIsRunningRHIInSeparateThread_InternalUseOnly", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
  "_GMainThreadBlockedOnRenderThread", referenced from:
      ASceneCaptureCamera::Tick(float) in Module.Carla.cpp.o
  "_GIsThreadedRendering", referenced from:
      ASceneCaptureCamera::Tick(float) in Module.Carla.cpp.o
      FRenderCommand::GetDesiredThread() in Module.Carla.cpp.o
  "_GMaxRHIShaderPlatform", referenced from:
      ASceneCaptureCamera::Tick(float) in Module.Carla.cpp.o
  "FRHICommandListBase::WaitForTasks(bool)", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
  "_GDynamicRHI", referenced from:
      ASceneCaptureCamera::WritePixelsNonBlocking(float, FRHICommandListImmediate&) const in Module.Carla.cpp.o
      ASceneCaptureCamera::WritePixels(float) const in Module.Carla.cpp.o
  "GetImmediateCommandList_ForRenderCommand()", referenced from:
      ASceneCaptureCamera::Tick(float) in Module.Carla.cpp.o
      TGraphTask<ASceneCaptureCamera::Tick(float)::EURCMacro_FWritePixelsNonBlocking>::ExecuteTask(TArray<FBaseGraphTask*, FDefaultAllocator>&, ENamedThreads::Type) in Module.Carla.cpp.o
      TGraphTask<ASceneCaptureCamera::Tick(float)::EURCMacro_FWritePixels>::ExecuteTask(TArray<FBaseGraphTask*, FDefaultAllocator>&, ENamedThreads::Type) in Module.Carla.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
ERROR: UBT ERROR: Failed to produce item: /Users/gleb/dev/deep-learning-learning/carla/Unreal/CarlaUE4 4.18/Plugins/Carla/Binaries/Mac/UE4Editor-Carla.dylib
Total build time: 26.00 seconds (Local executor: 0.00 seconds)
Command /Users/gleb/UnrealEngine_4.18/Engine/Build/BatchFiles/Mac/Build.sh failed with exit code 5

When I open the project through UE4Editor, it complains about the lack of the dylibs and tries to build them, but fails every time as well.

[thegleb]

Update: got it to complete the build by modifying the Carla.build.cs further:

    PublicDependencyModuleNames.AddRange(
      new string[]
      {
        "Core",
        // ... add other public dependencies that you statically link with here ...
        "RHI", // added this
        "RenderCore" // and this
      }
      );

[analog-cbarber]

I got this working using Xcode 8.2.1, which is based on clang 3.9. I had to modify the scripts to use clang/ clang++ without the version suffix. I did run into one problem that I do not understand:
the Makefile generated by the GenerateProjectFiles script is targeted at Linux instead of Mac :

BUILD = bash "$(UNREALROOTPATH)/Engine/Build/BatchFiles/Linux/Build.sh"
PROJECTBUILD = mono "$(UNREALROOTPATH)/Engine/Binaries/DotNET/UnrealBuildTool.exe"
...
UE4Editor:
         $(BUILD) UE4Editor Linux Development  $(ARGS)

When I manually changed Linux to Mac and add mono to my PATH, I was able to complete the
build. I cannot figure out how to fix the Makefile generation. Invoking the GenerateProjectFiles.sh
script with -Platforms=Mac doesn't do any good. Not sure what I did wrong.

In any case, if I modify the generated Makefile by replacing all instances of Linux with Mac
and replacing modifying the PROJECTBUILD definition to be the following, then the build works:

MONO = "$(UNREALROOTPATH)/Engine/Binaries/ThirdParty/Mono/Mac/bin/mono"
PROJECTBUILD = $(MONO) "$(UNREALROOTPATH)/Engine/Binaries/DotNET/UnrealBuildTool.exe"

[analog-cbarber]

It appears that the -makefiles flag to the UnrealBuildTool does not properly support Mac targets. The -cmakefiles appears to do the right thing, but I have not actually tried doing a build yet. Since it is not clear what version of llvm/clang is used by later releases of Xcode, and the 0.9 release of CARLA is using clang 5.0, I suspect that using cmake will be preferable to Xcode.

[nsubiron]

@analog-cbarber Thanks for the report!

In Linux we use a very specific version of the compiler because we need to link against libc++ (instead of the usual libstdc++ for Linux). In Mac, I imagine we can go with the default compiler installed like we do on Windows.

And for the sh scripts, they have been written for Linux and only tested on Linux, we may need to adapt them.

[analog-cbarber]

That's good, so the Xcode build approach may still be ok? So the main risk would be if CARLA started to depend on C++ features in clang 5.0 that are not yet supported in the Xcode variant?