Specially for the KRAVETS fashion house and their new collection «Dragonfly» (autumn - winter 2014/2015), an interactive floor «Dragonflies» was developed.

User interaction is based on the work of 3d cameras. A separate C++ module was written to track moving objects in the scene. It uses infrared images from cameras, several clever algorithms for tracking moving objects and a special marking algorithm (Hungarian algorithm). To synchronize several cameras with each other and calculate the position of the cameras relative to the displayed surface, a special calibration module was written. It uses well-known checkerboard pattern recognition techniques.

As for graphics, the Unity engine was chosen as a very flexible and convenient editor. User interaction is as follows. As soon as the camera system sees a person, dragonflies flock to him and begin to circle around, following him wherever he goes.

The tracking and calibration module has been integrated into Unity as a plugin by marshalling unmanaged C++ code to managed C# (.Net marshalling). This module represents the core of the interactive floor system, which is also used in other similar systems («Shallow water fish» and «Dolphins» interactive floor).