In recent years, the use of 3D scanners has gained increased popularity in various industries. From architecture and engineering to healthcare and entertainment, 3D scanners have changed the way we capture and replicate the physical world in digital form. However, with any technological advancement, the question of accuracy arises. How precise are these scanners in capturing the minutest details? Let's delve into the world of 3D scanning and explore its accuracy levels, limitations, and potential applications.
Before we dive into accuracy, let's first understand how 3D scanners work. 3D scanners are devices that capture the geometry and appearance of physical objects or environments using various technologies. These technologies include laser-based scanners, structured light scanners, and photogrammetry, among others. These scanners collect data by measuring points on the object's surface and create a digital representation known as a point cloud. This point cloud can then be processed to generate a detailed 3D polygonal model.
3D scanner accuracy relies on several factors including the type of scanner, the scanning technique and the nature of the scanned object. Typically, the accuracy of 3D scanners is within a range of 0.01 mm to 0.1 mm, but a fixed standard for accuracy is not necessarily required. Instead, the level of accuracy needed depends on achieving the desired results. For example, a less expensive handheld model may be suitable for your specific purposes, even if it sacrifices some accuracy. In return, it offers greater flexibility and adaptability to the scanning environment. Comparing accuracy figures across different scanner types overlooks important factors that influence scan precision. The focus should be on achieving accuracy that is sufficient for your specific needs and desired outcomes.
This refers to the capacity of a scanner to precisely capture the positioning of points within a three-dimensional space. The latest 3D scanners can achieve sub 0.1 of a millimetre accuracy, although this accuracy decreases as the scanning distance increases. Therefore, scanning small objects at close range yields better results than scanning larger objects from a distance.
The level of detail and resolution captured by a 3D scanner also impacts its accuracy. Scanners with higher resolution can capture finer details, leading to more accurate representations of the object. However, it's worth noting that extremely high-resolution scanners may result in larger file sizes and longer processing times.
Shiny or reflective surfaces can cause issues with capturing accurate data due to light reflection or refraction. Some scanners use specialised techniques to overcome these challenges, but it's important to consider the surface properties when assessing accuracy.
While 3D scanners have made significant advancements in accuracy, they still have some limitations:
Objects with complex shapes or occlusions (hidden areas) can pose challenges for traditional 3D scanners. These scanners rely on line-of-sight measurements, so areas not directly visible to the scanner may be inaccurately represented or missed altogether. You’d need to use a 3D CT scanner (3D-Computed Tomography) to get past this issue.
Transparent or translucent objects are difficult to scan accurately because light can pass through them rather than being reflected back to the scanner. This limitation affects the accuracy of capturing the object's internal structure.
Proper calibration of 3D scanners is crucial for achieving accurate results. Additionally, the expertise of the operator plays a vital role in positioning the scanner, choosing appropriate settings, and interpreting the data obtained. Lack of calibration or operator skill can lead to inaccuracies.
Despite the limitations, 3D scanners have found widespread applications across various industries. Some notable applications include:
Part Inspection refers to comparing the values obtained through a measurement device with available references, such as 3D CAD models or 2D drawings, to determine whether a product is acceptable or not.
3D scanners facilitate the replication of physical objects and enable reverse engineering processes, which is useful in industries such as manufacturing, automotive, and aerospace.
3D scanners aid in creating precise digital models that can be used for prototyping, product design, and testing.
Poor data costs the construction industry up to $88.69 billion per year, says FMI and Autodesk. If you rely on inaccurate data, you risk creating rework, delays, and budget overruns. How can you avoid these risks and improve the quality of your data?
One tool helping contractors collect more accurate data is 3D scanning. The technology uses laser beams to capture digital information about the surrounding area. Its accuracy allows contractors to better understand site conditions and eliminate rework.
Below, we look at how accurate 3D scanning is and describe the difference between accuracy and resolution. Plus, we’ll give you tips on choosing the right accuracy level for your next project.
When used correctly, 3D scanners produce measurements with an accuracy of +/- 1 mm. The accuracy of these measurements eliminates the need to return to the field.
3D scanning is also visually impactful. Once the scans are converted into digital files, you can use these files to virtually walk through your job site. You can also take measurements down to the millimeter within the file. This allows you to access information about the distance, area, and volume of the space whenever you need it, and from any location.
Want to learn how laser scanning can help you save time and money on projects? Download our e-book, The Beginner’s Guide to 3D Scanning.
Confused about the difference between accuracy and resolution, and how each applies to 3D scanning? Here’s a quick breakdown:
Accuracy is how close the 3D scanner’s measurements are to the true size of the object. For example, if a cube has a width of 50.50 mm and a 3D scanner captures its width as 50.48 mm, the scan is relatively accurate. This is because the measurement comes close to the true dimensions of the cube. If your measurements must have a low margin of error, you should increase the accuracy of your scans.
Accuracy is different from precision, which shows how repeatable a measurement is. The graphic below illustrates the difference between accuracy and precision:
Resolution is the distance between data points captured by the 3D scanner. If the data points are dense and close together, then the resolution is high, and the resulting scan will be crisp. If you need to capture fine architectural details or small objects, then you should increase the resolution of your scans.
How accurate should your scans be? It depends on the minimum level of accuracy needed to complete your project. If you want to monitor construction progress, then you probably don’t need measurements accurate down to the millimeter. A less accurate scan will still allow you to track construction progress.
Some projects require higher levels of accuracy, such as floor flatness reports or renovations. In these cases, the margin of error must be small, and scans should be accurate down to the millimeter. You can consult with a 3D scanning technician to determine the right level of accuracy for your individual project needs.
Although the construction industry has been slow to adopt 3D scanning, the technology is becoming the norm on projects for its accuracy, efficiency, and cost-savings. To learn more about laser scanning and how it can help with your next project, download our free e-book: