3DNL - The Netherlands from every angle

Smart Digital Realities that replicate real-life geoinformation provide valuable insights, and support the analysis and interpretation of infinite data inputs from the real or digital world. Commercial and government customers can use them to improve work processes and planning.

3DNL is a first-of-its-kind photorealistic digital twin of the entire Netherlands. It is based on aerial imagery and LiDAR data, collected with a Leica CityMapper-2 airborne sensor and made accessible through Cyclomedia’s Street Smart web viewer hosted on HxDR, Hexagon’s cloud-based storage, visualisation and collaboration platform.

3D digital realities are changing the game

Cyclomedia has provided 360-degree street-level visualisations for decades. Aware of the increasing demand for 3D data and wanting to maintain its position as a preferred content supplier, Cyclomedia recognised the benefits of creating an innovative hybrid data set, offering both price and product delivery advantages. By creating 3DNL, the company has produced a multipurpose digital twin. In addition to its direct use in Street Smart, users can also stream or download the 3D data for third-party applications.

"We are making a big impact by creating a new way for customers to interact with data and develop insights to create smarter cities, achieve more efficient construction and derive information from the data to provide knowledge," says Thomas Pelzer, product manager at Cyclomedia.

The Leica CityMapper-2, a state-of-the-art hybrid airborne sensor, is perfectly suited for efficient and accurate urban mapping. The simultaneous acquisition of oblique imagery and LiDAR point clouds produces perfectly registered consistent data. The narrow field of view minimises occlusions while the oblique scan pattern captures building facades from all angles. One flight instead of two reduces environmental impact, decreases data acquisition costs and takes advantage of limited flying windows.

The most important benefit of using a hybrid system lies in the quality of the data products. Image-only systems struggle to provide accurate data in shadows, urban canyons and under vegetation. The LiDAR data perfectly complements image data to fill the gaps. As an active sensor, it does not require light to create accurate data points and can provide returns from underneath vegetation. At the same time, the image data is crucial for the generation of textured 3D models. A hybrid sensor provides more information, more-accurate measurements and smoother surfaces in the mesh.

"Adding a LiDAR sensor to an oblique camera, as found in the Leica CityMapper-2, is a game changer. We have a strong preference for hybrid data and there are many advantages to joining forces on acquisition and development with a large global corporation such as Hexagon," says Pelzer. "We are always looking for new ways to bring best-in-class products to market and Hexagon shares our enthusiasm for innovation."

Hexagon also leverages the one-of-a-kind sensor technology for the HxGN Content Program’s Metro HD city data offering. Hybrid data of major cities are captured with the Leica CityMapper-2 and used to produce a full stack of exceptionally accurate, temporally consistent 2D and 3D data sets to satisfy even the most demanding applications. The Metro HD city data will be hosted and made available on HxDR.

Unmatched 3D mesh quality

To capture the Netherlands in its entirety under favourable conditions and to produce the best data set possible, Cyclomedia partnered with Hexagon to capture aerial data each year between February and October. After processing with Leica HxMap software, the aerial imagery and LiDAR data as input are converted into a mesh and added to 3DNL. The 3D data is hosted on HxDR and fully integrated into Street Smart.

HxDR enables users worldwide to unlock the data within 3DNL and to take advantage of a range of functions and features to explore and utilise 3DNL. Features include 3D city mesh measurements (distance, height, volume), asset management, sun and shadow analyses, and building cross-section analysis. The platform is also ideal for visualising projects for public review and allowing the virtual collaboration of professionals in any field.

Practical applications

Hexagon and its partners have made great strides toward creating a digital environment in which stakeholders and citizens can plan, visualise and simulate developments. Tasks such as importing CAD and BIM data, importing reality capture data, automeshing reality capture data, as well as virtual tours and flythroughs, annotations and photosphere locations are possible.

The broad range of applications appeals to government and commercial customers. For example, a solar company may download the model of a specific house, calculate the pitch and slope, create a solar plan and present a proposal to the house owner. Construction and engineering companies can download an area of interest, design a new build and determine the most efficient access and logistics for the construction phase. A governmental agency may calculate how many trees are in a neighbourhood, plot heat pockets and perform a shade analysis.

Cyclomedia’s and Hexagon’s collaboration on this ground-breaking 3D digital twin project demonstrates the potential for the large-scale simultaneous collection of imagery and point clouds with the Leica CityMapper-2.

A version of this case study was first published in GIM International as part of the Aerial Mapping & Earth Observation Weeks 2022.

Smart Digital Realities support the analysis and interpretation of the real and digital world, connecting users to valuable insights that improve work processes, planning and collaboration. 3DNL, a photorealistic 3D model of the Netherlands, is based on aerial data collected with the Leica CityMapper-2 airborne sensor and is accessible through Cyclomedia’s Street Smart web viewer hosted on Hexagon’s HxDR platform. Seamless data flow and processing ensure stakeholders have the information they need when they need it.