linux_build.md

Linux Build

Our current recommanded and tested environment is Ubuntu 16.04 LTS. Theoratically you can build on other distros and OSX as well but we haven't tested it.

Install and Build

It's super simple 1-2-3!

Note: You can either use Unreal 4.16 or 4.17, but not the older versions. Both versions have some known issues. Please see FAQ later in this doc.

1. Make sure you are registered with Epic Games. This is required so you can get Unreal engine's source code.
2. Clone Unreal in your favorite folder and run setup.sh (this may take a while!). Note: We only support Unreal 4.16 and newer.

     # go to folder where you clone GitHub projects
     git clone -b 4.16 https://github.com/EpicGames/UnrealEngine.git
     cd UnrealEngine
     ./Setup.sh
     ./GenerateProjectFiles.sh
     make

3. Clone AirSim and run setup.sh:

     # go to folder where you clone GitHub projects
     git clone https://github.com/Microsoft/AirSim.git
     cd AirSim
     ./setup.sh
     ./build.sh

Running AirSim on Linux

Go to Unreal folder and bring up Unreal Editor:

cd Unreal/Engine/Binaries/Linux
UE4Editor

On first start you might not see any projects in UE4 editor. Click on Projects tab, Browse button and then navigate to AirSim/Unreal/Environments/Blocks/Blocks.uproject. You will be then prompted by message "The following modules are missing or built with a different engine versions...". Click Yes. Now it might take a while so go get some coffee :).

Changing Code and Rebuilding

1. After making code changes in AirSim, run ./build.sh to rebuild. This step also copies the binary output to Blocks sample project. To clean and completely rebuild, first use ./clean.sh.
2. Start UE4Editor as described in previous section and double click on Blocks project. This will rebuild Unreal binaries as well.

Using AirSim Your Own Unreal Project

To setup your own Unreal environment see these instructions.

To update your project with AirSim, simply copy the AirSim/Unreal/Plugins folder in to your project. You can use this handy command line:

rsync -a --delete Unreal/Plugins path/to/MyUnrealProject

You can also copy clean.sh from AirSim/Unreal/Environments/Blocks folder to your Unreal project folder.

FAQ

What are the known issues with Unreal 4.16?

One of the major issue is this bug in Unreal. We have done a workaround for some parts of the code but we haven't tested if everything is covered. Another known issue is that when clicking "End" button causes Unreal to crash. A final knowm issue is that report function (when you press R key), also causes crash because of above reasons.

What are the known issues with Unreal 4.17?

At the time of writing (July, 2017), version 4.17 is still in "preview" stage and is unstable. We have seen some rare but random crashes during startup. You might get warning that AirSim plugin is incompatible which you can ignore. Also, when clicking on "End" button freezes the Unreal Editor requiring to manual kill of its process.

Unreal crashed! How do I know what went wrong?

First go to folder MyUnrealProject/Saved/Crashes and then search directories for MyProject.log file. At the end of this file you will see stack trace and message. Also see Diagnostics.txt file.

How do I use IDE in Linux?

You can use Qt or CodeLite. Instructions for Qt Creator is available here.

Can I cross compile for Linux from Windows machine?

Yes, you can but we haven't tested it. You can find instructions here.

What compiler and stdlib AirSim uses?

We use same compiler that Unreal uses which is Clang 3.9. AirSim's setup.sh will automatically download Clang 3.9. We also need to use libc++ that Unreal uses. The libc++ code is cloned by AirSim's setup.sh in to llvm-source folder and built in llvm-build folder. The cmake is the instructed to use libc++ from llvm-build folder. For other flavors of Linux and more info, please see http://apt.llvm.org/.

Can use AirSim with Unreal 4.16?

Yes! The *.Build.cs files are, however, no longer compatible (you will get compile error). You can find files for 4.16 as *.Build.4.16.cs so just rename those.

What CMake version AirSim build uses?

3.5.0 or higher. This should be default in Ubuntu 16.04. You can check your cmake version using cmake --version. If you have older version the follow these instructions or see cmake website.

Can I compile AirSim in BashOnWindows?

Yes, however you can't run Unreal from BashOnWindows. So this is kind of useful to check Linux compile, not for end-to-end run. See BashOnWindows install guide. Make sure to have latest version (Windows 10 Creators Edition) as previous versions had various issues. Also don't invoke bash from Visual Studio Command Prompt otherwise cmake might find VC++ and try and use that!

I made change in Visual Studio but there is no effect

Sometime Unreal + VS build system don't do recompile if you change only header file. So try making some cpp file dirty.

Where can I find more info on running Unreal on Linux?

• Start here - Unreal on Linux
• Building Unreal on Linux
• Unreal Linux Support
• Unreal Cross Compilation