A research sim for drones and cars that outgrew its hangar

What it does AirSim is an open-source simulator that drops into Unreal Engine (and experimentally Unity) to model drones, cars, and other autonomous vehicles with physically and visually realistic behavior. It exposes RPC-based APIs in C++, Python, C#, and Java so you can programmatically control vehicles, retrieve sensor data, and log training frames for deep learning and reinforcement learning. The same APIs are packaged as a standalone cross-platform library, letting you move code from the simulator to a companion computer on a physical vehicle.

The interesting bit The project treats simulation as a first-class production step, not just a preview: it supports software-in-the-loop with PX4 and ArduPilot and hardware-in-the-loop with PX4, and includes a dedicated Computer Vision mode that strips out physics entirely so you can position cameras arbitrarily to harvest depth, disparity, and segmentation masks.

Key highlights

• Plugs into Unreal Engine as a drop-in plugin; an experimental Unity plugin also exists.
• Supports software-in-the-loop and hardware-in-the-loop simulation with PX4 flight controllers.
• Includes a “Computer Vision” mode for collecting depth, surface normals, and object segmentation without vehicle physics.
• Recent additions include a ROS2 wrapper, optical flow camera, cinematographic camera, and GPS movement APIs.
• Cross-platform API library designed to run on both the simulator and real vehicle companion computers.

Caveats

• Microsoft has announced this original 2017 repository will be archived in the coming year with no further updates effective immediately; the company is shifting focus to a new commercial product, Microsoft Project AirSim.
• The Unity plugin and release are explicitly marked as experimental.

Verdict Grab the code if you need a mature, free autonomy sandbox for Unreal Engine, but look elsewhere if you want active maintenance or a Unity-first workflow. Researchers migrating to Microsoft’s upcoming commercial Project AirSim platform may also want to evaluate that instead.