A researcher measures the width of a stone structure. [Photo provided to China Daily]

A mountain of information is needed to make the rendering of scenic spots realistic, especially in showing the details of the buildings. There are more than 10 steps to digital reconstructing each scenic spot.

Based on laborious studies by Guo and her students of the Old Summer Palace and maps drawn up in 1933, 1965 and 2002, the team was aware of how hills and water systems had changed over the years, making it easier to collect and collate information on the sites.

Referring to design drawings when the park was built, paintings and calligraphy works created at that time, and other archives and material, the team analyzed the characteristics of each building and the spatial aspects of the scenic spots and determined the characteristics of special buildings, such as how to arrange artificial hills, flowers and plants.

Researchers then attempted to draw up a plan of each scenic spot and design the buildings, furnishings, decorations and gardens based on the information they got, and then build the 3D scenes.

However, historical archives and other material are far from a complete repository of the information needed.