A compiler and scene generator for the Scenic scenario description language, with (partial) interfaces to the Grand Theft Auto V and Webots simulators. The src/scenic directory contains the package proper, while the examples directory has many examples of Scenic programs.

For a description of the language and some of its applications, see our PLDI 2019 paper. Scenic was designed and implemented by Daniel J. Fremont, Tommaso Dreossi, Shromona Ghosh, Xiangyu Yue, Alberto L. Sangiovanni-Vincentelli, and Sanjit A. Seshia.

If you have any problems using Scenic, please contact Daniel at dfremont@berkeley.edu or submit an issue to our GitHub repository.

• Installation
• Basic Usage
• Interfacing to GTA V
• Interfacing to New Simulators
• License

You need Python 3.6 or newer. The setup.py script will handle installation of dependencies (run python setup.py install). Some scenarios using OpenStreetMap data require the pyproj package and will prompt you if you don't have it (we haven't listed it as a dependency since there seem to be issues building it for Windows at the moment).

The top-level interface to Scenic is through the function scenic.scenarioFromFile, which compiles the given file into a Scenario object (see scenic/__main__.py for an example). The scenic module can also be run as a standalone application, in which case it renders simple schematics of the generated scenes. You can try this out as follows:

python3 -m scenic examples/gta/badlyParkedCar2.sc

A window should pop up with a diagram of a scene, in this case generated from the badly-parked car scenario from our GTA case study. If you close the window, a new scene will be generated. At least on OS X, you can kill the generator by right-clicking on the graphics window's icon in the Dock and selecting Quit. Control-C may not work due to how Matplotlib works. For demos, you can tell the generator to repeatedly generate new scenes after a given delay like so:

python3 -m scenic -d 5 examples/gta/bumperToBumper.sc

Scenarios for Webots or Guideways work the same way. For example:

python3 -m scenic examples/webots/mars/narrowGoal.sc
python3 -m scenic examples/webots/road/crossing.sc
python3 -m scenic examples/guideways/uberCrash.sc

There are many more examples of Scenic programs in the examples folder.

Interfacing Scenic to GTA V requires a GTA V plugin, which you can find here.

If you want to interface Scenic to a simulator, there are two steps. The easy part is using the APIs provided by scenic to load Scenic programs and generate scenes. To get an idea of how this works, you can look at scenic/__main__.py to see the source for the standalone application used above.

The more involved step is importing into Scenic information about the virtual world provided by the simulator, e.g. obstacles, regions, and types of objects. This repository contains four world models you may find helpful as examples, under scenic/simulators. Each consists of a master Scenic module which must be imported by every scenario using that simulator, possibly together with auxiliary Python and Scenic modules. The models are:

• webots/mars/mars_model.sc: The model for the Mars rover example in Webots. This model is extremely simple and might be a good place to start.

• gta/gta_model.sc: The model for the GTAV world.

• webots/road/road_model.sc: A general model for Webots worlds generated using the Webots OSM importer.

• guideways/guideways_model.sc: A prototype model for worlds derived from guideways data from the Intelligent Intersections Toolkit.

Scenic is distributed under the 3-Clause BSD License. However, it currently uses the GPC library (through the Polygon3 package), which is free only for non-commercial use. GPC is used only in the triangulatePolygon function in scenic.core.geometry, and you can alternatively plug in any algorithm of your choice for triangulation of polygons with holes. We plan to replace GPC with a BSD-compatible library in the near future.