Digital twins and smart cities
Fabrice Marre is the geospatial innovation manager who heads up the R&D team at Aerometrex. His role involves keeping up with existing and emerging 3D visualization technologies within the geospatial industry and beyond.
Marre has been using Unreal Engine for years, leveraging the technology’s photorealistic rendering to showcase 3D models generated from photogrammetry in the most engaging and realistic way possible. “The visual quality of Unreal Engine is exceptional, but it takes some experience to produce high-quality content quickly for very large assets,” he says.
Photogrammetry capture and real-time visualization
Aerometrex delivers 3D models that are captured using aerial photogrammetry techniques. Using a large format camera attached to a fixed-wing aircraft, Marre and his team captured and generated a large-scale 3D model of Adelaide, where the company is headquartered, and its surrounding area. They also captured and produced a 3D city model of the central business district (CBD) area at a higher resolution from a helicopter platform.
The 3D models generated then went through a manual clean-up process to remove any geometry and texture artifacts. These models were split into tiles with different levels of detail and exported in many 3D formats including OBJ and FBX. To integrate the 3D city models into Twinmotion, the team produced multiple objects made of merged OBJ tiles and then used tiles at lower levels of detail the further they were from the focus area.
A strategy to handle city-scale projects
Up to now, Twinmotion has generally been used to create smaller projects than this. A large project might include visualizing a football stadium or part of a housing estate. As Aerometrex has shown, the tool has the capability to visualize environments on a far grander scale.
That said, an endeavor as ambitious as visualizing an entire city does come with its own set of challenges. “Clear data management and asset production strategy, as well as a good understanding of the limit of the workstation, are essential when dealing with very large datasets,” explains Marre. “A large 3D model cannot be loaded at once. Splitting, merging, and decimating the data into manageable assets is the key.”
A huge city environment results in a hefty 3D model. Having strategies in place to ease the load on your workstation is essential. “Twinmotion does not currently support dynamic loading of level of detail, so in the case of Adelaide, we used high-resolution 3D model tiles over the CBD and merged them together,” says Marre. “We then merged a ring of low-resolution tiles around the CBD and used lower level of detail tiles the further away we are from the CBD.”
The team also manually hid the individual blocks of the 3D models that were not visible from a specific point of view to free up RAM and improve the real-time experience.
The success of the project has secured Twinmotion a permanent place in the Aerometrex pipeline. “Features such as drag-and-drop functionality, texture management, an extensive realistic asset library, customizable vegetation assets, and environment settings make the process of producing photorealistic visuals easy,” explains Marre. “All these benefits, in my view, place Twinmotion ahead of the pack.”
Marre says that Twinmotion will stay as their tool of choice for producing high-quality videos quickly and easily, while Unreal Engine will be dedicated to more advanced applications, including interacting with assets and developing interactive VR experiences. “It’s great to see real-time technology becoming a force for innovation across industries,” he says. “It’s very exciting for me to add a bit of the geospatial industry to the mix.”
Developing the smart cities of the future
The smart cities of tomorrow will be built on the datasets of today. Their foundations will be digital as much as physical, with large-scale city environments designed and managed using real-time visualization. “These real-time environments provide an accurate base to develop designs, test scenarios, and communicate a clear vision of what a future city could look like,” says Marre.
Interactive 3D is a universal language. It provides the tools to quickly test complex hypotheses, dynamically change lighting and weather conditions, add life to a static model, and produce realistic visualization.
While architecture and urban design concepts can be visualized on their own over a limited space, large-scale city environments can add context to a project and stimulate thinking outside the box. Large contextual 3D data enables us to not only focus on a design, but also to simulate how a design will fit in its environment in a realistic way.
With the Adelaide project, Aerometrex has discovered a new, fast option for creating city-scale visualization. “Twinmotion is an amazing tool and I believe it should not be restricted to small environments,” says Marre. “It has the capability to load very large datasets, provide solutions for large-scale design visualization, and expand into new markets.”
For those of us intrigued about the urban spaces of the future, Aerometrex provides a fascinating glimpse into the large-scale environment datasets that will inform their development.