carla/Docs/build_system.md

Build system

This document is a work in progress, only the Linux build system is taken into account here.

The most challenging part of the setup is to compile all the dependencies and modules to be compatible with a) Unreal Engine in the server-side, and b) Python in the client-side.

The goal is to be able to call Unreal Engine's functions from a separate Python process.

In Linux, we compile CARLA and all the dependencies with clang-6.0 and C++14 standard. We however link against different runtime C++ libraries depending on where the code going to be used, since all the code that is going to be linked with Unreal Engine needs to be compiled using libc++.

Setup

Command

make setup

Get and compile dependencies

• llvm-6.0 (libc++ and libc++abi)
• rpclib-2.2.1 (twice, with libstdc++ and libc++)
• boost-1.69 (headers only)
• googletest-1.8.0 (with libc++)

LibCarla

Compiled with CMake (minimum version required CMake 3.9).

Command

make LibCarla

Two configurations:

	Server	Client
Unit tests	yes	no
Requires	rpclib, gtest, boost	rpclib, boost
std runtime	LLVM's libc++	Default libstdc++
Output	headers and test exes	libcarla_client.a
Required by	Carla plugin	PythonAPI

CarlaUE4 and Carla plugin

Both compiled at the same step with Unreal Engine 4.21 build tool. They require the UE4_ROOT environment variable set.

Command

make CarlaUE4Editor

To launch Unreal Engine's Editor run

make launch

PythonAPI

Compiled using Python's setuptools ("setup.py"). Currently requires the following to be installed in the machine: Python, libpython-dev, and libboost-python-dev; both for Python 2.7 and 3.5.

Command

make PythonAPI

It creates two "egg" packages

• PythonAPI/dist/carla-X.X.X-py2.7-linux-x86_64.egg
• PythonAPI/dist/carla-X.X.X-py3.5-linux-x86_64.egg

This package can be directly imported into a Python script by adding it to the system path

#!/usr/bin/env python

import sys

sys.path.append(
    'PythonAPI/dist/carla-X.X.X-py%d.%d-linux-x86_64.egg' % (sys.version_info.major,
                                                             sys.version_info.minor))

import carla

# ...

or installed with easy_install

easy_install2 --user --no-deps PythonAPI/dist/carla-X.X.X-py2.7-linux-x86_64.egg
easy_install3 --user --no-deps PythonAPI/dist/carla-X.X.X-py3.5-linux-x86_64.egg