* In order to use this app, you need the "AR Mail from Harbin" postcards. If you do not have them ready on hands, please visit the site below, download the postcards, and print them. http://uqr.to/armail * This project was presented at Siggraph 2017. * This project was nominated for two categories in Unity Awards 2017. "AR Mail from Harbin" is a small augmented reality (AR) application that works with a set of postcards. Each postcard is printed with a portion of the plan of St. Sophia, the main church in the center of the city of Harbin. A user can assemble a 3D model of the building by laying out the postcards in the proper composition. By combining a photogrammetric capture of the church, AR technology, and traditional paper media, this tool enhances visitors’ experience at the historical location, increases their understanding of its spatial design, and promotes social interaction between the visitors on site and their friends in remote locations, all in a playful setting.