CiThruS2 (See-Through Sight 2) is a virtual city environment and framework built in Unreal Engine 5 to aid in testing and developing various traffic-related systems, drone systems and vision-based systems. The environment is based on the real city of Hervanta, Finland, and it supports features such as simulated cars, drones and pedestrians, weather, seasonal effects, a changeable time of day and real-time video recording and streaming.
Currently, the environment is only officially supported on Windows. Most features are also available on Linux and macOS, but using either of them will require manually setting up the dependencies and content.
To use the environment on Windows, you must first make sure PowerShell, Visual Studio 2022, CMake and Unreal Engine 5.4 are installed on your computer. Then, run the setup.cmd script, which will automatically set up dependencies and download the CiThruS2 content, which is not included in this repository due to GitHub storage limitations. Please note that the script will download ~7GB of data: make sure your computer has enough storage space.
After successfully running the script, open the CiThruS.uproject project file in Unreal Engine. Click "Yes" when it asks whether you want to build the code. After building, the Unreal Engine editor will automatically open the environment. The editor will take several minutes to open and it will build shaders for 2min ~ 30min depending on the hardware used, but subsequent startups will be much faster. If the editor fails to open or the build process fails, please check that the setup script ran successfully and did not generate errors. The main components of CiThruS2 should be usable without any dependencies if there are issues with building them.
If you wish to delete CiThruS2, simply delete the directory in which you downloaded this repository: the setup script does not install anything elsewhere on your computer (other than CMake if it was not already installed. This is because the dependencies may install it.)
Old versions of CiThruS2 for older Unreal Engine versions are available on separate branches. They do not have the latest features and will no longer be updated, but they are otherwise usable. When switching branches, it's recommended to first clean the repository directory of all files not included in the repository to avoid version conflicts.
If you are using CiThruS2 in your research with a focus on ground vehicles and traffic, please cite the following paper:
E. Gałązka, T. T. Niemirepo, and J. Vanne, “CiThruS2: Open-source photorealistic 3D framework for driving and traffic simulation in real time,” in Proc. IEEE Int. Conf. on Intelligent Transportation Systems, Indianapolis, Indiana, USA, Sept. 2021.
If you are using CiThruS2 in your research with a focus on UAVs/drones, please cite the following paper:
E. Gałązka, A. Leppäaho, and J. Vanne, “CiThruS2: open-source virtual environment for simulating real-time drone operations and piloting,” in Proc. IEEE Int. Automated Vehicle Validation Conf., Austin, Texas, USA, Oct. 2023.
In other kinds of research, please cite the one you believe to be the most appropriate. If you're not sure which one to choose, we recommend the most recent paper.