New Technology Uses Point Cloud Data to Reproduce Roads and Public Structures in Virtual Space

A research team reports on "point cloud data" technology for reproducing actual cityscapes and buildings in virtual spaces. Laser measurements are merely a "collection of points," the team reports. However, by using a platform that makes it possible to share 3D data, including point cloud data, the range of its application will increase, the researchers explain. 

The team was led by Kenji Nakamura, professor at Osaka University of Economics, Ryuichi Imai, professor at Hosei University, Yoshinori Tsukada, associate professor and Yoshimasa Umehara, lecturer at Setsunan University, and Shigenori Tanaka, professor at Kansai University. 

A report by the team was published in English in the Journal of Digital Life, a multidisciplinary, peer-reviewed, open access, online journal based in Japan.

What Is Point Cloud Data?

Point cloud data is a huge aggregation of points with information such as XYZ (width, height, depth) coordinates and RGB (red, green, blue) values of color. These can be used to record detailed data of objects in actual sites. 

For example, take the decision to deconstruct the former Miyakonojo Civic Hall (Miyakonojo City, Miyazaki Prefecture). It was designed by the late Kiyonori Kikutake, one of the leading architects of the post-war period. In 2019, a group of volunteers worked to preserve the architecture in cyberspace. They used 3D laser scanners to archive not only the exterior but also the interior stage, audience seats, and the structure behind the ceiling. 

Point cloud data is not only used for "preservation" of buildings but is also attracting interest in the field of "i-Construction." That is a field where ICT is being applied to construction sites and civil engineering work. 

The technology can also be applied to infrastructure inspections. For that reason, the Ministry of Land, Infrastructure, Transport, and Tourism is working to utilize point cloud data to improve the efficiency of road management. Specifically, they and to identify roads at risk in the event of a disaster. 

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3D Point Studio Platform Takes On Challenges

Although it is certainly a useful technology, Dr Nakamura and his colleagues indicate that it is difficult to use point cloud data wisely in accordance with its intended purpose.

When a road is modeled in 3D using point cloud data, it is easy for people to visually understand at a glance that the roadway extends from here to there and has a sidewalk next to it. Or that there are trees, a traffic light, and a road sign along it. However, when analyzing point cloud data with existing systems, the point cloud data itself is nothing more than a set of points. So it is not possible to assess basic information, such as where something is located.

To solve this problem, Dr Nakamura, Dr Imai, and their colleagues at Intelligent Style Co have developed 3D Point Studio. This is a platform that promotes the utilization of point cloud data. In addition, they have made some of the functions available to the public free of charge.

Creating 'Digital Twin' Public Spaces

With 3D Point Studio, "area data," which holds information on the location and attributes of natural and artifacts, is provided to point cloud data. This makes it possible to extract only "a specific set of points" from the vast amount of point cloud data that has not been organized as data. 

Because of the machine-readable (readable and processable by a computer) attributes of area data, it is possible to extract only the slope of a road from point cloud data of a cityscape. Or for example, to extract only utility poles from "pillar-like objects" lined up along a roadway. 

The technology that creates a "twin" of real space in a virtual space and performs simulations is called "digital twin." Dr Nakamura and his colleagues refer to the technology that can analyze roadways, road signs, and utility poles in their respective virtual spaces as "digital twin for public structures."

Since point cloud data is large in size and cannot be easily viewed, Dr Nakamura and his team divided the functions of 3D Point Studio into an online version for data viewing and information sharing. They also made an offline version for data processing and analysis. 

Award-Winning Technology Used in Real Life

When a road construction worker wants to quickly view a construction site, he can access the online version of the website. There he can "preview" the site in 3D graphics in a few minutes. The URL of the viewed data can be issued and shared with others. 

Its offline version also has a number of practical analysis functions that allow users to analyze and edit point cloud data from multiple perspectives. For example, 3D Point Studio can be used to compare point cloud data of prefectural roads published by Shizuoka Prefecture at different times of the year. When doing so, Intelligent Style Co has created an environment that allows users to inspect how the areas damaged by the typhoon changed before and after the typhoon. 

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For this achievement, the company received the 2019 i-Construction Grand Award (Excellence Award). The award is given by the Ministry of Land, Infrastructure, Transport, and Tourism to outstanding construction and civil engineering-related projects. 

In the future, the research team hope to promote the results of its research by conducting various studies related to architecture and construction, not only for the purpose of maintaining and managing buildings and infrastructure with 3D Point Studio.

This article was first published on Sankei Biz by the Journal of Digital Life. You can also read the article in Japanese.

Author: Taketoshi Noma

Also available to read in English on JAPAN Forward: other articles first published on Sankei Biz by the Journal of Digital Life.