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AI/TLDR

CARLA

The open driving simulator autonomous-driving research is built and validated in

Simulators & Synthetic EnvironmentsOpen source
Language
C++
License
MIT (code) / CC-BY (assets)

Overview

CARLA is, in the project's own words, "an open-source simulator for autonomous driving research", developed from the ground up to support the development, training and validation of autonomous driving systems. Where a general game engine gives you a world, CARLA gives you a world plus the research scaffolding around it: open digital assets — urban layouts, buildings, vehicles — together with the protocols to drive them programmatically.

Two capabilities do most of the work for machine-learning teams. Sensor suites are specified flexibly, so a vehicle can be fitted with whatever combination of cameras, lidar and other sensors an experiment calls for, and the same scene re-run with a different rig. Environmental conditions are configurable in the same way, which is how a policy gets tested against weather and lighting it would take months to encounter on a real road. Together they make it practical to generate labelled training data and to replay the same scenario until a controller stops failing it.

The project is long-running and actively developed — the `ue5-dev` branch tracks the Unreal Engine 5 line — with documentation at carla-ue5.readthedocs.io covering building on Linux and Windows, a first-steps tutorial, the asset catalogue, the Python API reference and the blueprint library. Licensing is split the way simulators usually are: the CARLA code is MIT, the assets are CC-BY, and bundled dependencies such as PROJ, SQLite, Xerces-C and Eigen keep their own open-source licences.

What it does

  • Open digital assets: urban layouts, buildings, vehicles and pedestrians for driving research
  • Flexible sensor-suite specification, so the same scene can be re-run with a different sensor rig
  • Configurable environmental and weather conditions for stress-testing a policy
  • Python API for scripting scenarios, collecting data and driving vehicles programmatically
  • Unreal Engine 5 line under active development on the `ue5-dev` branch
  • Documentation covering builds, first steps, the asset catalogue, the Python API and the blueprint library

Getting started

CARLA is built from source against Unreal Engine. The commands below are the ones given in the `ue5-dev` README; the full build guides live at carla-ue5.readthedocs.io.

Clone the UE5 branch

The repository is large — clone the branch you intend to build.

bashbash
git clone -b ue5-dev https://github.com/carla-simulator/carla.git CarlaUE5

Run the interactive setup (Linux)

The setup script walks through dependencies and the engine checkout.

bashbash
cd CarlaUE5
./CarlaSetup.sh --interactive

Install the Python API

Build the client-side Python package so scripts can talk to the simulator.

bashbash
cmake --build Build --target carla-python-api-install

Read the first-steps tutorial

The documentation site covers building on Linux and Windows, the asset catalogue, the blueprint library and the Python API reference.

texttext
https://carla-ue5.readthedocs.io

Commands and code are distilled from the project's own documentation — always check the official repo for the latest.

When to use it

  • Reach for it when a driving policy has to be validated against scenarios that are unsafe or impractical to stage on a real road
  • Reach for it when you need labelled perception training data with a sensor rig you control
  • Reach for it when the same scenario must be replayed deterministically across model revisions
  • Reach for it when testing how a controller degrades under weather and lighting changes

How CARLA compares

CARLA alongside other open-source simulators & synthetic environments tools AI/TLDR tracks, ranked by GitHub stars.

ToolStarsWhat it does
AirSim★ 18.6kMicrosoft's Unreal Engine simulator for drones and cars, with a Computer Vision mode, weather effects and C++/Python/C#/Java APIs for generating training data and testing control policies.
CARLA★ 14.5kThe open driving simulator autonomous-driving research is built and validated in
AlpaSim★ 1.3kNVIDIA's open-source closed-loop simulator for testing end-to-end autonomous-driving policies on neural-rendered scenes built from real driving logs, run as swappable gRPC microservices.