What Is Point Cloud Processing? A Comprehensive Guide to Its Uses and Benefits on Construction Sites

Introduction: What is this frequently heard term “point cloud processing”?

In recent years, you may have increasingly heard the terms “point cloud” and “point cloud processing” on construction sites. These are new technical terms that have emerged with the digitization of surveying and construction management, but many young engineers and workers may think, “I’ve heard the name, but I don’t really understand it…” Point cloud processing may sound difficult at first, but simply put it is a technology for recording and utilizing the shape of a site in three dimensions as countless points. In this article, we will gently explain the basics of what point cloud processing is, the situations on construction sites where it can be used, how work changes after introducing it, and the benefits. At the end of the article there is also an introduction to a cutting-edge tool called “LRTK” that allows anyone to easily capture point clouds using a smartphone. Grasp the image of how point clouds can be applied and consider moving forward with on-site adoption.

What is a point cloud? How is it different from photos?

A point cloud, literally, is a “collection of a large number of points.” It refers to a representation of the shape of real-world objects such as buildings or terrain recorded as countless measured points (three-dimensional coordinate data) using laser measurement or similar methods. Each point in the data contains X, Y, and Z coordinate values indicating actual position (height and distance information), and the higher the point density, the more closely the shape of the real object can be reproduced. For example, if you convert ground leveled by heavy machinery into point cloud data, the terrain’s bumps and hollows at that moment are digitally preserved, producing a three-dimensional model that can be viewed from any angle on a computer.

So what’s the difference from photos or drawings? The biggest difference is that point cloud data is 3D, so you can “measure” things afterward. Photos may look realistic but are flat images, so you cannot directly measure exact dimensions or distances of the subjects shown. Drawings such as plans are often sketches based on measurements of only parts of the site and may not fully represent complex shapes. In contrast, point clouds record the object’s surface as it is, comprehensively and three-dimensionally, so a single measurement can provide detailed information across a wide area. After acquisition, point cloud data can be viewed from any angle on a computer and arbitrary cross-sections can be displayed to take measurements, meaning additional measurements can be added later as needed. In other words, point cloud data is a full-scale 3D copy of the site that provides objective information including parts not visible in photos or drawings. The significance of measuring in three dimensions is that every shape on site can be completely and accurately digitally recorded.

Point cloud processing basics: How do you scan and use it?

Here is a broad overview of how point cloud data is handled on an actual site. There are technical processes involved, but this section highlights the key points for beginners.

• 3D scanning (measurement): First, scan the site to acquire point cloud data. There are several measurement methods: tripod-mounted 3D laser scanners that measure the surroundings with lasers, drones that take aerial photos and create 3D models, and more recently, methods that use a smartphone’s built-in LiDAR sensor for easy scanning. Regardless of method, they all share the ability to acquire a large number of points in a short time to measure the entire site. Unlike conventional manual surveying where you measure point by point with a tape or total station, machines can measure wide areas all at once in three dimensions.

• Processing point cloud data: The raw point cloud data obtained from scanning consists of millions to hundreds of millions of point coordinates. Dedicated point cloud processing software is used to clean and convert the data into a usable form. For example, you remove unwanted points introduced during measurement (airborne noise, passersby, etc.), align and merge separate point clouds scanned from multiple positions into a single coordinate system, and, if needed, create surfaces from the point cloud to generate 3D models or automatically generate cross-sections and plan views (these are advanced topics and are not detailed here). Through this processing, precise 3D data that reproduces the entire site is completed.

• Using the data: Processed point cloud data can then be used in various site tasks. You can directly measure dimensions on a PC or tablet, calculate volumes and areas for quantity estimation, and compare completed structure point clouds with design data (drawings or 3D models) to quickly check whether the finished work matches the design. You can also generate arbitrary cross-sections from the point cloud to easily verify heights and slopes. Because the data can be stored in the cloud or on shared servers, it is easy to check point clouds from the office or use the same 3D information for meetings with stakeholders, enabling digital information sharing. In this way, the cycle of acquisition → processing → application allows point cloud data to be effectively utilized in site operations.

Where to use point clouds on construction sites

Now let’s look at specific situations in construction and civil engineering where point cloud data is useful. Below are representative use cases where the advantages of point clouds are clear compared to conventional methods.

• As-built management (post-construction shape verification and inspection): As-built management is the process of verifying and recording whether completed structures or terrain match the design drawings after construction. Traditionally, selected measurement points were spot-checked and compared with drawings, but by using point clouds you can measure and check the entire structure at high density, dramatically reducing oversights. By overlaying acquired point cloud data with the design 3D model, you can immediately see which parts are higher or lower than the design values. Deviations down to the millimeter level can be identified in 3D, allowing early correction to prevent rework and drastically improving quality control accuracy. In addition, point cloud data itself serves as a detailed record of the finished condition, providing evidence for inspection reports and serving as a digital record to refer back to for future maintenance to see “how it was originally constructed.”

• Record preservation (progress and condition records): Compared to photos or drawings, records made with point cloud data excel at preserving the entire scene as it was. For example, if you record the pre-construction terrain or excavation status with point clouds, you won’t have to worry about “I forgot to take a photo of that spot…” since the whole space including the surroundings is digitally preserved and you can extract the necessary information later from the data. Storing intermediate progress and the completed state as point clouds makes it possible to reproduce fine details that later would not be apparent from drawings or reports, aiding future verification and troubleshooting. Because digital data requires less storage space and does not degrade like paper documents or photo albums, it can be accumulated as a high-precision record asset of the site.

• Safety checks: Point cloud technology is powerful for safety management as well. Its greatest advantage is that it allows measurement at hazardous locations without people approaching them. Using remotely operated laser scanners or drones, you can obtain detailed terrain data from a safe distance even in steep or collapse-prone areas. Surveying at heights or in narrow spaces can be completed quickly without erecting scaffolding, reducing risks to workers and improving efficiency. Sharing acquired point cloud data via the cloud enables supervisors or engineers who are not on site to review objective current conditions together, facilitating collaborative safety decisions. Moreover, augmented reality (AR) technologies that leverage point clouds can overlay locations of buried pipes or cables on the real scene to help prevent accidental damage during excavation. In this way, point clouds not only measure but also visualize “invisible hazards,” strengthening safety measures.

• Quantity calculation (volume and area calculation): Point cloud data is powerful for calculating quantities for earthwork and similar tasks. Traditionally, calculating cut and fill volumes required measuring ground elevations before and after construction, creating cross-sections, and performing manual calculations using the average-section method—time-consuming work. With point clouds, you can scan the terrain before and after filling or excavation and calculate the differential volume to obtain earthwork quantities instantly. Because point cloud data includes subtle surface irregularities, it enables high-precision volume calculations that consider depressions or bulges that traditional methods might miss. For example, scanning a spoil heap and immediately obtaining its volume lets you know on-site how many truckloads of soil there are, enabling quicker decisions about truck arrangements. If point clouds have been captured, you can also change the calculation area and recalculate later without returning to the site, so requests to recompute quantities for a particular section can be handled immediately. As a result, the time required for quantity calculations is greatly reduced, dramatically improving the efficiency and accuracy of progress management.

Benefits of point cloud processing: What improves after adoption?

As seen above, point cloud technology can bring various benefits to construction sites. Here are three easy-to-picture points for beginners that summarize how work improves when using point clouds.

• Faster and more accurate: Introducing point cloud measurement improves both work speed and accuracy. Wide-area site surveys that used to take half a day can sometimes be completed in minutes or tens of minutes with laser scanners or drones. Because you can measure everything at once, measurement omissions decrease and rework is prevented. Unlike manual surveying, machine-based measurement reduces human error and yields precise results, increasing the reliability of quality control and quantity calculations. Non-contact measurement also allows quick and safe measurement of hazardous areas, so safety benefits should not be overlooked. Leveraging point cloud technology is a trump card for addressing severe labor shortages by enabling “accurate surveying and construction management quickly even with small crews.”

• Understandable even if you can’t read drawings: Point cloud data is intuitive visual 3D information. When explaining as-built conditions to stakeholders, things that were hard to understand from paper drawings or numerical reports become obvious when viewing a 3D point cloud model. Showing 3D data to newcomers who are not used to reading drawings, craftsmen, clients without technical knowledge, or local residents makes it easy for anyone to grasp the site’s condition. Because information is conveyed in a form close to the actual scene, things that are hard to express in words or on flat drawings become understandable to everyone. This reduces miscommunication, making coordination among site staff and explanations to clients smoother.

• Easy for teams to use: Because point cloud data is digital, it is easy to share and use within a team. Storing point clouds and derived drawings or models in the cloud means supervisors in remote offices or subcontractors can view and discuss the same data. This reduces the traditional constraint of “you have to go to the site to understand the situation” and enables remote, three-dimensional understanding and decision-making. Data is also easy to copy and process, so it can be handed to other departments or design personnel as needed. With everyone holding the same digital “copy” of the site, information mismatches and duplicate work are reduced, improving project-wide productivity. Point clouds become a collaborative platform that connects site and office, people and people.

Point cloud surveying you can do with a smartphone! A simple introduction to LRTK

If you feel that point cloud measurement requires expensive machinery or special skills, here’s good news. With a tool called LRTK, recently introduced, you can perform high-precision point cloud measurement using only a smartphone. LRTK is a system consisting of a small RTK-GNSS receiver (high-precision GPS device) that can be attached to a smartphone and a dedicated app; when attached to a smartphone it enables real-time acquisition of centimeter-level position coordinates (cm level accuracy, half-inch accuracy). Then, by scanning the surroundings with the smartphone’s camera or LiDAR, it automatically generates 3D point cloud data with absolute coordinates on the spot. There are no complicated operations—this is truly a revolutionary solution that turns a smartphone into a high-precision 3D scanner.

So what specific benefits does LRTK offer? Compared with conventional laser scanners or drone-based point cloud measurement, it dramatically lowers the barrier to on-site use in the following ways:

• One person can complete the job on site: With a smartphone plus LRTK, measurement tasks can be completed by a single person on site. There’s no need to carry heavy tripod-mounted equipment or have another person hold a prism for surveying. Newcomers who are familiar with intuitive smartphone operation can simply walk around and scan, requiring no special skills. Its mobility is excellent for measuring in narrow interiors or tunnels, and it’s convenient to pull out and use whenever needed. Even on sites short-staffed, one person can perform sufficiently accurate surveying, reducing waiting times and improving personnel allocation efficiency.

• Cloud integration for data sharing: Point cloud data acquired with LRTK can be uploaded to the cloud and shared and used immediately. After finishing a scan on site, office staff can open the same data to take measurements or overlay it with design drawings to check as-built conditions. Dedicated cloud services also offer tools to measure distance, area, and volume with one click, so basic quantity calculations and cross-section checks can be performed even without specialized on-site software. Data is stored securely over the Internet, eliminating the hassle of carrying USB drives and enabling everyone in the company to share the latest 3D site data. Real-time information transfer between site and office will significantly improve the speed and accuracy of construction management.

• Intuitive use with AR display: One advantage of using a smartphone is the AR (augmented reality) function that overlays camera images with digital data. Leveraging LRTK’s high-precision positioning, you can overlay design data or point cloud data onto the actual scene on the smartphone screen. For example, AR display of the planned structure model on the pre-construction ground lets people immediately grasp the completion image. During construction, overlaying the design model with the actual as-built point cloud on the phone allows on-the-spot verification of whether the current position matches the design. Inspection tasks that relied on intuition while reading drawings can now be done accurately by following AR guidance and marking accordingly, so anyone can perform them precisely. Additionally, if you record buried pipe positions with point clouds before backfilling, you can later point your phone at the ground after backfilling to visually confirm the location and depth of the hidden pipes, aiding safe construction. By directly connecting digital data and the site through AR, construction management practices are being greatly innovated.

As described above, LRTK makes point cloud measurement—previously the domain of specialist surveyors—much more accessible. Without purchasing expensive equipment, you can use an existing smartphone to easily try three-dimensional site capture. Point cloud processing is not an inscrutable special topic. Start digital measurement from familiar places and experience the benefits of point clouds—fast, accurate, and easy-to-understand—on your site!