Modeling The Vision Of A Better City With LIDAR
LIDAR is a fast and efficient method to capture high-resolution data with accurate measurements. But in this episode, the focus is not on using LIDAR to make better measurements. Rather the talk is about how point cloud data can be used to tell a story. The guest tells how creating a film with 3D LIDAR data of a city provided a medium that could be consumed by the public to understand how a city could be transformed.
About The Guest
Benjamin Muller is a team leader at Leica Geosystems in the R&D section. Doing mechatronics, they combine disciplines such as software development, mechanics, and electronics to develop devices such as drive chains for laser scanners and total stations.
Benjamin was part of a project that used LIDAR data to create a film that communicated the vision of a better city. He emphasizes the importance of using easily understandable films to communicate complex details. In his words:
“Facts do not always speak for themselves. If a visualization can be wrapped around the truth, and packaged in a story, it can reach a lot more people. And this could be a driver for change.”
How Is LIDAR Useful In 3D City Modelling?
Getting insights into a whole city is an important element in the process of transforming a city into a future-proof city. It is not possible to get this kind of insight when walking through a city because at that moment you are only viewing the city from a very small perspective.
LIDAR makes it possible to make 3D models of the whole city, with accurate measurements that preserve the integrity of the city features. Visualizing a city in this way provides a wider perspective on how various changes would impact a city. Viewing a city and its surroundings in a new perspective unlocks new ideas and better strategies of transforming a city. Additionally, LIDAR data collection can be done whenever required to capture any new changes that have happened in the city.
Drawbacks in Working with LIDAR
During LIDAR data collection, massive amounts of point clouds are captured. Even for a small city, the size of data captured can easily grow into several terabytes. With data of this size, many LIDAR experts have reported that a great part of their work, over 80%, is filtering the data. It can take months to process LIDAR data for a city.
Processing LIDAR data for a city is costly both in terms of time and money – which can run into several hundreds of thousands of dollars. Using AI in processing can considerably reduce processing times, but even then working with the data requires expensive and powerful equipment. For most people, who may just need a one-time visualization of a part of a city, it is uneconomical to buy such expensive infrastructure just to visualize a small part of the city.
How LIDAR Was Used To Visualize a Better and More Sustainable City
A project undertaken in the city of St Gallen in Switzerland used LIDAR data to create 3D models of the city. It added contributions from different experts to create subsequent versions of how the city can be transformed. These versions were pieced together to create a 30-minute long film that helped to communicate to people a vision of a greener, more sustainable city.
The advantage of using a film as a communication tool is that it is easier to understand. It effectively communicates the message to people who may not deliberately read detailed books on how to transform a city. Additionally, a film can efficiently reach a wider audience in society and inspire people to become a part of the change for a better future city.
From A Vision to A Strategy
The film of the city was created to communicate a vision of a better future city. But it also transformed to a strategizing tool. With this visualization, decision-makers could formulate a step-by-step strategy that can be applied to make the city more sustainable and healthy for both the people and the whole environment. This led to the creation of 16 books alongside the film, which contained detailed information on how to do the desired transformations in the city.
Other Uses of 3D City Models
Various sectors including tourism can benefit from 3D models of a city. Using augmented reality the 3D models can be used to support digital tourism. While visiting a site, tourists can also view the site from different perspectives, and experience things that would otherwise not be obviously visible.
For cities where you need to report the changes you are doing to structures on your property to city authorities, visualizing the changes in a 3D model provides an opportunity for understanding the impact of the changes to the city and the environment.
How Can We Democratize 3D City Data?
With AI it is possible to build services that process LIDAR data on the cloud. These services can then be accessed through a browser by the public. In this way, more people can visualize the data without having to buy very expensive infrastructure or become an expert in visualization. Providing easier and cheaper ways for the public to consume LIDAR data is an important step in its democratization. But if only a few specialists are able to use the data, it will still remain a very expensive luxury to have it.
HxDR (Hexagon Digital Reality)
HxDR is one example of a publicly available platform for viewing 3D models of cities. You have to register first before you can view detailed 3D city models. At the moment, there are models of several cities in Europe and the US on the platform. Some of the cities have high-precision geospatial data and you can also purchase parts of the city that you are interested in.
A platform like this is only the beginning of a transformation to have access to 3D data, but we expect there is more coming in the future.