carla/Docs/how_to_build_on_linux.md

How to build CARLA on Linux

This guide has been tested only on Ubuntu 16.04.

Install the build tools

$ sudo apt-get install build-essential cmake ninja-build

To avoid compatibility issues between Unreal Engine and the CARLA dependencies, the best configuration is to compile everything with the same compiler version and C++ runtime library. We use clang 3.9 and LLVM's libc++.

Install clang 3.9

$ wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
$ sudo apt-get update
$ sudo apt-get install -y clang-3.9 clang++-3.9

You may need to change your default clang version to compile Unreal

$ sudo ln -s /usr/bin/clang-3.9 /usr/bin/clang
$ sudo ln -s /usr/bin/clang++-3.9 /usr/bin/clang++

Build Unreal Engine

Download and compile Unreal Engine 4.17. Here we will assume you install it at "~/UnrealEngine_4.17", but you can install it anywhere, just replace the path where necessary.

Unreal Engine repositories are set to private. In order to gain access you need to add your GitHub username when you sign up at https://unrealengine.com.

$ git clone --depth=1 -b 4.17 https://github.com/EpicGames/UnrealEngine.git ~/UnrealEngine_4.17
$ cd ~/UnrealEngine_4.17
$ ./Setup.sh && ./GenerateProjects.sh && make

Check Unreal's documentation "Building On Linux" if any of the steps above fail.

Setup CARLA plugin

Go to "CARLAUE4/Plugins/Carla" folder and run the setup script. This downloads and compile all the dependencies, takes a while but you only need to do this once

$ ./Setup.sh

Now you can use the Makefile to compile and test the code. However, the rebuild script of the main project will do that already, see next section.

It is recommended to do a check to see if everything worked fine

$ make check

Build and launch CARLAUE4

Define the environment variable UE4_ROOT pointing to Unreal Engine's installation folder.

In the root folder of CARLAUE4 you can find "Rebuild.sh" script. This deletes all intermediate files, rebuilds whole CARLA, and launches the editor. Use it every time you update CARLA.

$ UE4_ROOT=~/UnrealEngine_4.17 ./Rebuild.sh

It looks at the environment variable UE4_ROOT to find the right version of Unreal Engine. You can also add this variable to your "~/.bashrc" or similar.