Summary
The paper deals with one of the most important Italian initiatives in the field of VR applied to cultural heritage. The “L’Ara com’era” (The Ara as it was) project, held in 2016-2019, was devoted to the Ara Pacis, a Roman monument built between 13 and 9 BC. Once entered the Ara Pacis Museum, visitors could focus on nine points of interest wearing Samsung Gear VR visors, fitted with a Samsung S7 smartphone. Through films, virtual reality and immersive technologies, visitors had the opportunity to enjoy bird’s-eye views of ancient Rome, experience a sacrificial rite and see the marble reliefs in their original polychromy.

Innovative VR tools and techniques
• A 3D tracking implementation was developed to use rounded irregular objects (e.g. bas-relief or statues) as markers for AR contents
• The system recognizes three-dimensional bas-reliefs and statues, carries out real-time tracking and overlaps the original polychromy to the works of art

VR in education
• Real objects (the marble reliefs in their present state) and 3D objects (the marble reliefs in their original polychromy) merged into one image to show the monument in its original colors
• Through Samsung Gear VR viewers, visitors experienced that ancient sculptures and reliefs were originally polychrome; colors of the 3D objects were based on conservation reports
• The combination of VR, AR and films, as well as the participation of two popular Italian actors as narrator’s voice, made the tale of the monument’s history and original functions very engaging