In this paper we present DejaVu, a novel 3D virtual world
co-simulator for ‘visual diffing’ of cyber-physical system
deployments in indoor and outdoor environments. Using
faster-than-real-time simulation and efficient recording DejaVu
can record days of simulation data, including environmental,
sensor and network data for later replay and analysis.
DejaVu enables developers to replay and visually compare
multiple simulations simultaneously using different visual
diffing techniques, including ghosts, paths, colour and
size, highlighting differences between runs, including energy
consumption, radio metrics, movement, etc. We demonstrate
several of these visual diffing techniques in an CPSenhanced
evacuation case study.