We are very proud to announce CARLA 0.9.0!
In this release we have completely redesigned the networking architecture and built from scratch a new Python API that completely changes the way CARLA is used. Every vehicle can now be controlled, cameras can be placed anywhere, and any number of client applications can connect simultaneously to the same instance of the simulator. But beware, this is a development release. The amount of changes we are doing is enormous, so we wanted to make available some of the latest features for our brave users that want to start experimenting with the new CARLA API. Many things that were there will be temporarily unavailable and many new issues will appear, but we believe all these changes are worth it and put us straight on our road map for creating a great autonomous driving simulator for everyone!
Disclaimer said, let’s talk a bit about the cool features that this release brings.
The server-client communication has been redesign to allow any number of clients connecting and making changes to the simulation concurrently. It is finally possible to have a multi-player simulation with different AIs and humans driving around in the same city.
We have switched our networking protocol to an RPC model, using the great rpclib library. The new model uses two TCP ports, by default 2000 and 2001, the first one used to control the simulation with rpclib, the second one does the streaming of the sensor data. Both client and server work asynchronously, and although many optimizations are yet to be made, the latency is already pretty low.
The multi-client support opens the door to very interesting scenarios and integrations with third-party software like traffic control tools and pedestrian behaviour modelling libraries. It’s great for scalability as each of the clients can be run on a different node.
The final goal of the new API is to allow users to control every aspect of the simulation. Our view is to have everything available from Python; loading maps, adding sensors, adding static obstacles, controlling vehicles and pedestrians, and what not. The 0.9.0 API is just a step forward on that direction, but there are a bunch of cool things that you can already do with it.
But first we need to introduce a few core concepts:
All the actors can be created and destroyed at any point during the simulation, and all of them can be controlled or moved around. In this release only vehicles and cameras are available but in coming releases we’ll add pedestrians and traffic lights as well.
Let’s take a quick peek at how it looks, the following code adds a red Mustang to the simulation and enables its autopilot so the car can drive freely around the city on its own
from carla import * client = Client('localhost', 2000) world = client.get_world() blueprint = world.get_blueprint_library().find('ford.mustang') blueprint.set_attribute('color', '255,0,0') transform = Transform(Location(x=230, y=195, z=40), Rotation(yaw=180)) mustang = world.spawn_actor(blueprint, transform) mustang.set_autopilot()
Now let’s attach a camera to this vehicle so we can take a look at what’s going on
blueprint = world.get_blueprint_library().find('sensor.camera') blueprint.set_attribute('post_processing', 'SceneFinal') camera = world.spawn_actor( blueprint, Transform(Location(x=0.5, z=1.8)), attach_to=vehicle) camera.listen(lambda image: do_something(image))
the callback function passed to the
listen method will be called every time a
new image is received. This callback is executed asynchronously, this
considerably speeds up the parsing of images. Now it is possible to do things
like saving images to disk keeping up with the speed of the simulator.
Actors can also be teleported and moved around the city, for that we have
location = vehicle.get_location() location.x += 10.0 vehicle.set_location(location)
and in the special case of vehicles, they can be controlled too in the usual way
For the full list of methods available take a look at the Python API Reference.
We’ll revisiting and improving this API in the coming releases. If you find any issues or think of cool improvements that can be added, please don’t hesitate to share it with the community at our GitHub or Discord chat.
Many features that are present in previous releases are gone in this one. Things like Lidar, pedestrians, bikes, synchronous mode, or quality settings. This is due to the fact that we have switched to a new API and many things haven’t been ported yet. We’ll be adding them soon in the coming releases. As said before, this is a work in progress, we want to share this progress with the community, after all we think this can be already useful for a lot of people.