51World creates digital twin of the entire city of Shanghai

As recently reported on The B1M, 51World individually modeled over 20 landmark structures including the Oriental Pearl and Shanghai Tower, and used data from satellites, drones, and sensors to generate digital versions of countless other buildings, roads, waterways, and green spaces using an algorithm. Ultimately, the plan is to turn this model into a true digital twin that will be continuously updated in near real time.

Digital twins are precise virtual representations of physical assets that use connected digital information—again from geographic information sensors, satellites, drones, and other sources—to mirror reality. In the case of cities, planners and engineers can study digital twins and gain insights for improving services, planning developments, optimizing buildings' systems, and monitoring traffic flow. Designers can simulate ideas in the live city environment before they are constructed, and understand in advance the impact of decisions such as where to position a bus stop, or the footprint of a new housing development.

It’s natural that digital twins in the hands of a private company or national government raise concerns about rights, ethics, and privacy. But what is actually captured is just trends. All the data is anonymized; facts about specific individuals and their movements are not tracked.

To optimize the photorealistic real-time rendering of the Shanghai model in Unreal Engine, the entire simulation is divided into two-square-kilometer segments, which are loaded and unloaded according to the camera view—a trick often used in video games. Closer objects appear in finer detail, showing accurate environmental reflections, soft shadows on surfaces, and lifelike shading effects in accordance with the weather. The team used Unreal Engine’s Sun and Sky model to simulate natural daylight. 

The Shanghai model is clearly one of the most advanced thus far, but several other cities are now investing in virtual clones of one kind or another. While not a true digital twin, virtual Helsinki, a digital replica of the Finnish capital created by VR studio Zoan, is used for everything from the promotion of tourism to virtual real estate tours.

Digital twins are still in their infancy, but their potential to transform our urban landscapes is huge. With the rise of artificial intelligence and machine learning, smart cities with autonomous decision-making capabilities are no longer the stuff of science fiction, but a very probable future reality.