Test #3 is built on the Massachusetts Institute of Technology (MIT) FlightGoggles simulator, a first-of-its-kind virtual reality environment for drone research and development. MIT has modified FlightGoggles to include software for a drone racing simulation environment based on the Unity3D game engine. It includes Robotic Operating System (ROS) binding for integrating autonomy software and Unity assets for environments that resemble drone racing scenarios.
FlightGoggles simulator and several training courses are now available open-source to the public and are hosted on GitHub. You can find the source code for the simulator, more information about how to get started, and some example challenge files here: http://flightgoggles.mit.edu/