floor plan raised up from 3D laser scanning

An Introduction to 3D Laser Scanning

Paul Tice3D Laser Scanning Leave a Comment

The 3D laser scanning market is exploding across the world. The market is predicted to grow from $5.5 billion to $8.51 billion by 2028.

This innovative technology is revolutionizing not only the AEC industry but the legal and historic preservation fields as well.

Embracing 3D scanning opens up possibilities for enhanced design, improved documentation, and advanced analysis.

In this guide, we’ll explore what 3D scanning is and why it’s so important in these fields. Let’s dive in and learn what 3D laser scanning is and the opportunities it offers across AEC projects.

Unraveling the Definition and Advantages of 3D Laser Scanning

What is 3D laser scanning? At its core, 3D laser scanning is a process that captures the shape, geometry, and texture of objects or environments using laser beams.

It involves sending out laser pulses and measuring the time it takes for the laser to return, creating a point cloud of millions of individual points that represent the scanned object or space in three dimensions.

What’s the result? You get an accurate representation of a structure or whatever it is you’re scanning, whether it’s an as-built project or a product design.

The accuracy of the scan is critical in the AEC industry, and it’s one of the key advantages of using 3D laser scans.

Since the scan lets you create accurate as-built documentation you have the foundation to create accurate BIM models. It’s helpful when conducting clash detection to avoid conflicts during construction.

Speed is another advantage of 3D laser scanning. Traditional measurement methods, such as manual surveying or hand-drawn sketches, can be time-consuming and labor-intensive, not to mention prone to errors.

Scanners can capture intricate details of complex structures and hard-to-reach areas, which may be challenging or unsafe to measure manually.

This speed allows for more efficient project workflows, limits the time required for site visits, and speeds up the overall project timeline.

Non-Invasive Data Collection

3D laser scanning is a non-invasive way to collect data. Scanners can capture data from a distance without direct contact with the object or structure being scanned.

This non-invasiveness is valuable in historic preservation, where delicate or fragile structures need to be documented without causing damage.

The non-invasive nature of 3D laser scanning also applies to the legal field. You can collect data without disturbing evidence. The data collected can get used in a variety of scenarios, from

3D laser scanning is a non-invasive way to collect data. Scanners can capture data from a distance without direct contact with the object or structure being scanned.

This non-invasiveness is valuable in historic preservation, where delicate or fragile structures need to be documented without causing damage.

The non-invasive nature of 3D laser scanning also applies to the legal field. You can collect data without disturbing evidence. The data collected can get used in a variety of scenarios, from accident reconstruction to criminal investigations.

3D Laser Scanning and BIM

We mentioned earlier that the accuracy of 3D laser scanning plays a vital role in BIM modeling. With high levels of accuracy, you can trust the information in front of you.

That’s not the only way the data collected from 3D laser scans supports your projects.

Comprehensive Data for Planning and Design

The data captured through 3D laser scanning provides a comprehensive understanding of the existing conditions of a building.

BIM models enhanced with laser scan data enables project stakeholders to assess structural integrity, identify clashes or interferences, and analyze the feasibility of design changes.

This level of detail allows for informed decision-making, reducing design conflicts, and facilitating more efficient construction processes.

Improved Collaboration and Communication

Laser scan data can be shared and accessed remotely, allowing team members to visualize and interact with the as-built environment without being physically present on-site.

This shared understanding improves coordination, minimizes conflicts, and facilitates effective communication among different disciplines involved in the project.

Facility Management and Maintenance

Beyond the design and construction phases, 3D laser scanning contributes to facility management and maintenance.

The detailed and accurate data captured during scanning can be integrated into BIM models to create a digital twin of the building.

This digital twin serves as a reference for facility managers, allowing them to access critical information about the building’s systems, equipment, and maintenance history.

It simplifies tasks such as space management, asset tracking, and maintenance planning, leading to more efficient facility operations.

Types of 3D Scanning Technology

Now that you understand how and why 3D laser scanning supports a variety of projects, let’s take a look at the types of 3D laser scanning technology.

A basic understanding of the technology lets you make the right decisions and choose the best approach for your project.

As you’re about to find out, not every 3D laser scanner is suitable for every project. The approach you choose impacts the accuracy, speed, resolution, and final quality of your scans.

Structured Light Scanning

Structured Light Scanning is a popular method for capturing 3D data using projected light patterns. This technique involves projecting a series of known patterns onto an object or scene and then capturing the deformations of these patterns using cameras.

The system can calculate the shape and geometry of the subject by analyzing the distortions.

One of the strengths of structured light scanning is its high level of accuracy and precision. It’s also capable of capturing a large number of data points in a short amount of time.

It can capture intricate details and produce highly accurate 3D models. This makes it well-suited for applications such as reverse engineering and quality control.

Time-of-Flight Scanning

Time-of-Flight (TOF) Scanning is a 3D scanning technology that measures the time it takes for a laser pulse to travel to an object and back to the scanner.

This method calculates the distance between the scanner and the object based on the speed of light, allowing for the creation of a detailed 3D representation.

TOF scanning excels in capturing large-scale environments with high accuracy. It is commonly used for outdoor scanning, such as topographic mapping, roadway mapping, and landscape modeling. It can also be used for building information modeling (BIM), urban planning, and environmental monitoring.

One of the limitations of TOF scanning is its reduced performance in situations with limited visibility, such as dense vegetation or foggy conditions. Additionally, the accuracy of TOF scanners may decrease with increasing range, so it is important to consider the scanning requirements of the specific project. TOF however does offer longer ranges than phase-shift scanning (below).

Laser Triangulation

Laser Triangulation is a technique where a laser line or multiple laser points are projected onto an object, and a camera captures the deformation of the laser pattern.

The system calculates the shape and depth information of the object by analyzing the geometry of the laser pattern.

Laser triangulation delivers a high level of accuracy and resolution. It can capture fine details with precision.

You can scan in real-time with laser triangulation, which gives you immediate feedback during the scanning process. This can be beneficial for alignment, positioning, and verifying the captured data.

Real-world applications of laser triangulation include automotive manufacturing, robotics, medical imaging, and precision engineering. It is commonly used for dimensional inspection of manufactured parts, 3D modeling of industrial components, and monitoring surface deformations.

Phase Shift

Phase shift laser scanning is a relatively shorter ranged technology compared to TOF that uses lasers to create detailed images or maps of objects or surfaces. Phase shift offers very dense point clouds suitable for photorealistic projects and works by rapidly moving a laser beam back and forth across the object, while also slightly changing the phase, or timing, of the laser light.

This change in timing helps capture more information about the object’s shape, texture, or depth. By combining all the measurements from different phases, a highly accurate and detailed image or map can be created. It’s like shining a laser on an object and moving it around really fast while also adjusting the timing of the laser light to gather a lot of information about the object’s features.

Photogrammetry

Photogrammetry isn’t a laser scanning method per se, but it is used to create 3D representations of a building or scene.

Instead of using laser beams to collect and measure data, it uses photographs taken at different angles. The photos overlap and get stitched together in specialized software to create a 3D visualization.

One of the major strengths of photogrammetry is its versatility. It can be applied to a wide range of objects and environments, from small-scale objects to large landscapes.

Real estate agents use this technology to create 360-degree tours of properties. It’s used in drone surveys to measure the distance between buildings or objects.

Is it as accurate as 3D laser scanning? It depends on image resolution, camera quality, the number of overlapping images, and lighting conditions.

The Basic Steps in the 3D Scanning Process

No matter which method of capturing data you choose, you’re going to have to make sure that your scans are accurate. There are several basic steps to get the most out of your scans.

For starters, make sure that the initial laser scanner position is set up in a prime location with a good amount of vertical geometry to ensure good stitching (registration) of subsequent scans.

Once you start your scan, the scanner emits laser beams or light patterns and collects the reflected signals using sensors or cameras. These signals contain detailed information about the geometry and surface characteristics of the scanned subject. Also, it is a good practice when scanning to eventually return to the initial scan location to “close the loop” on the scan dataset altogether. This allows the algorithms to properly correct for error.

The data then gets processed using specialized software to create a digital 3D model. This involves aligning and registering multiple scans to create a complete and seamless representation.

The software analyzes the data points and generates a dense point cloud or mesh that accurately represents the shape, texture, and spatial details of the scanned object or environment.

At this point, you can use the 3D model for documentation, design, or analysis or process it further.

For a more comprehensive understanding of the 3D laser scanning process, we have an in-depth article on our website that delves into the workflow of the process.

Mistakes to Avoid When Starting Out in 3D Laser Scanning

Are you just getting started in the world of 3D laser scanning? You need to be aware of the most common mistakes and steer clear of them. You’ll save time, money, and stress.

For those of you working with a new scanner for the first time, you might feel like a kid with a shiny new toy. You just want to play with it and jump right in to create your first scan.

Take the time to read the user manual, learn about the specifications, and practice using the equipment before diving into complex projects. You’ll learn how to calibrate and register the device and avoid costly mistakes or inaccurate deliverables to potential clients.

Calibration ensures that your equipment is correctly configured, while registration aligns multiple scans together into a cohesive 3D model. Glossing over these steps will result in errors and inaccuracies.

Another common mistake is neglecting the planning part. Be sure to evaluate the site before you start scanning. Assess the environment, identify potential obstacles, and plan your scanning path accordingly, ensuring you have a path that returns to your original start position. The exception to this is if you are using ground control points, which can offer confidence in the data without loop closure.

Part of the planning process includes understanding the lighting conditions and how they impact the result. Depending on the scanning method you use, you could end up with poor quality scans or the loss of important details because you didn’t read the lighting conditions correctly. Laser scanners in the near visible light spectrum of infrared may collect noisy data in sunlit conditions or in some cases, produce no data whatsoever.

Pay attention to ambient lighting and use supplementary lighting when necessary to ensure optimal scan quality. You might need to experiment with different lighting setups can help you identify the most effective approach for your specific scanning environment. If you are scanning to create a photorealistic dataset, it may be worth considering using an external DSLR camera shot from the same nodal point as the scanner and merging those photos with the 3D point cloud. More information can be found on colorizing scan data in our LinkedIn Learning course, “FARO SCENE 3D Laser Scan Registration”.

Do you think the job is done once the object is scanned? All you did was collect data. That data needs to be refined and processed to create 3D models.

Get familiar with post-processing software and techniques to clean up the scans, remove noise, and generate high-quality models. The time spent in post-processing will make a huge difference to the quality of your scans and improve the final output.

Learning All About 3D Laser Scanning

There’s no question that 3D laser scanning adds value to your project, whether you’re a facility manager or personal injury attorney.

As you embark on your journey into 3D laser scanning, remember to choose the right technology and avoid the common scanning mistakes that can jeopardize the quality of your data.

Do you want to learn more about 3D scanning? We have plenty of resources to help you get started. Check out our tutorials and LinkedIn courses today.

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