carla/Docs/build_system.md

Build system

• Setup
• LibCarla
• CarlaUE4 and Carla plugin
• PythonAPI
  • Versions 0.9.12+
  • Versions prior to 0.9.12

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-8.0 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++.

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Setup

Command

make setup

Get and compile dependencies

• llvm-8 (libc++ and libc++abi)
• rpclib-2.2.1 (twice, with libstdc++ and libc++)
• boost-1.72.0 (headers and boost_python for libstdc++)
• googletest-1.8.1 (with libc++)

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LibCarla

Compiled with CMake (minimum version required CMake 3.9).

Command

make LibCarla

Two configurations:

	Server	Client
Unit tests	Yes	No
Requirements	rpclib, gtest, boost	rpclib, boost
std runtime	LLVM's libc++	Default libstdc++
Output	headers and test exes	ibcarla_client.a
Required by	Carla plugin	PythonAPI

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CarlaUE4 and Carla plugin

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

Command

make CarlaUE4Editor

To launch Unreal Engine's Editor run

make launch

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PythonAPI

Versions 0.9.12+

Compiled using Python's setuptools ("setup.py"). Currently requires the following to be installed in the machine: Python, libpython-dev, and libboost-python-dev, pip>=20.3, wheel, and auditwheel.

Command:

make PythonAPI

Creates two files that each contain the client library and correspond to the supported Python version on the system. One file is a .whl file and the other is an .egg file. This allows for the option of two different, mutually exclusive ways to use the client library.

A. .whl file

The .whl is installed using the command:

 pip install <wheel_file>.whl

There is no need to import the library path directly in scripts as is required in previous versions or .egg files (see section Versions prior to 0.9.12); import carla is sufficient.

B. .egg file

See the section Versions prior to 0.9.12 for more information.

Versions prior to 0.9.12

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

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-py3.7-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

# ...

Alternatively, it can be 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-py3.7-linux-x86_64.egg