Build system for the new architecture of CARLA

Demo project for developing the new build system and architecture of CARLA Simulator.

This new architecture supports multi-client multi-agent communication, basically any number of Python clients can connect and send instructions to the simulator simultaneously. The result is a new API that allows a finer control of each actor in the scene

import carla

client = carla.Client('localhost', 8080)
client.set_timeout(1000)

print('client version: %s' % client.get_client_version())
print('server version: %s' % client.get_server_version())

world = client.get_world()

blueprint = random.choice(world.get_blueprint_library())

transform = carla.Transform(
    carla.Location(x=-12.5, y=24.0, z=2.0),
    carla.Rotation(yaw=-90))

actor = world.spawn_actor(blueprint, transform)

while True:
    control = carla.VehicleControl(
        throttle=random.uniform(0.3, 1.0),
        steer=random.uniform(-0.1, 0.1))

    actor.apply_control(control)

    time.sleep(1)

Design

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.

Compilation

Required installed dependencies,

$ sudo add-apt-repository ppa:ubuntu-toolchain-r/test
$ sudo apt-get install clang-5.0 lld-5.0 g++-7 ninja-build python python-pip python3 python3-pip libboost-python-dev
$ pip2 install --user setuptools nose2
$ pip3 install --user setuptools nose2

Required compiler

• clang++-5.0

Best if it is set up as default version of clang

$ sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/lib/llvm-5.0/bin/clang++ 101
$ sudo update-alternatives --install /usr/bin/clang clang /usr/lib/llvm-5.0/bin/clang 101

Everything is compiled with -std=c++17.

Required CMake 3.9 or higher.

Required Unreal Engine 4.19, install with the usual

$ git clone --depth=1 -b 4.19 https://github.com/EpicGames/UnrealEngine.git ~/UnrealEngine_4.19
$ cd ~/UnrealEngine_4.19
$ ./Setup.sh && ./GenerateProjectFiles.sh && make

and set your UE4_ROOT environment variable

$ export UE4_ROOT=~/UnrealEngine_4.19

Once everything is installed, run one of the following commands

$ make launch   # Compiles CARLA and launches Unreal Engine's Editor.
$ make package  # Compiles CARLA and creates a packaged version for distribution.
$ make help     # Print all available commands.

Compilation details

Here a detailed description of the different modules that need to be compiled. The Makefile compiles these modules incrementally as needed.

Setup

Command

$ make setup

Get and compile dependencies

• llvm-5.0 (libc++ and libc++abi)
• rpclib-2.2.1 (both with libstdc++ and libc++)
• boost-1.67 (headers only)
• googletest-1.8.0 (with libc++)

LibCarla

Compiled with CMake (min. 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 4.19 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-0.9.0-py2.7-linux-x86_64.egg
• PythonAPI/dist/carla-0.9.0-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(
    'dist/carla-0.9.0-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-0.9.0-py2.7-linux-x86_64.egg
$ easy_install3 --user --no-deps PythonAPI/dist/carla-0.9.0-py3.5-linux-x86_64.egg