What is 3D scanning and How does it work?
What is 3D scanning, and How does it work?
In this article, we introduce the various major 3D scanning methods that are gaining a variety of important uses in the industry.
Introduction
Did you know that 3D scanning can be a great way to start a 3D printing project? In fact, creating a 3D representation of an object can be started from scratch using 3D modeling software or a 3D scanning process. If you are interested in this 3D method, you may want to know how it works.
3D scanning is the method of analyzing an entity or real environment to gather data about its shape and possibly its formation(e.g., color). The gathered data can then be utilized to create 3D digital models.
A 3D scanner can be established on many additional technologies, individually with its own restrictions, benefits, and costs. There are still many restrictions on the type of objects that can be digitized. For example, optical technology may encounter many problems with dark, shiny, reflective, or transparent objects. For example, industrial computed tomography scans, 3D scanners with structural light, LiDAR 3D scanners, and Time Of Flight can be used to build digital 3D models without destructive testing.
Photogrammetry is the science of measuring from a photograph. This method uses the parallax obtained between several photos taken from different perspectives.
The collected 3D data is useful for various applications. The entertainment industry widely uses these devices movies and video games, including virtual existence. Other common applications of this technology contain extended reality, motion capture, gesture recognition, robotic mapping, industrial structure, orthoses and prostheses, reverse engineering and prototyping, quality control, inspection, and digitization of cultural artifacts.
What is 3D scanning?
3D scanning is the process of analyzing a real-world object collecting all the data to reconstruct its shape and appearance digitally. Thanks to this process, the object can be turned into a 3D model that can help you as a basis for the 3D project you want to develop, but it can also be used to reconstruct, analyze or simulate an idea. Are useful.
3D scanning is a technique for capturing the shape of an object using a 3D scanner. The result is a 3D object file that can be saved, edited, and even printed in 3D. There are many different 3D scanning technologies for 3D scanning of objects, environments, and people. Each 3D scanning technology has its own limitations, benefits, and costs.
The basic principle of 3D scanning is to use a 3D scanner to collect data on a subject. The subject can be:
- An object
- An environment (such as a room or even a landscape)
- One person (3D body scan)
Some 3D scanners can collect shape and color data simultaneously. The scanned color surface is called a three-dimensional texture.
3D scans are compatible with computer-aided design (CAD) software and 3D printing after modeling using 3D software. Also, 3D scanning can provide a lot of information about designing an object in a process called reverse engineering.
3D scanners are powerful tools for professionals in several industries such as automotive, aerospace, dentistry, and jewelry and more artistic applications such as video games, special effects, and animated films. 3D scanning technologies depend on additional physical regulations and can be categorized into the following types:
- Laser triangulation: It spreads the laser beam on a surface and measures the deformation of the laser beam.
- Structured light: A light pattern’s deformation when displayed on a surface to scan the surface shape in three dimensions.
- Photogrammetry: Also called “3D scanning of photos”. This technology reconstructs a subject in 3D from two-dimensional images with computer vision and computational geometry algorithms.
- Contact-based 3D scanning technology relies on sampling from several points on the surface, measured by a mechanical, optical, or physical probe.
- Laser pulse: The laser beam is based on Time of Flight (ToF). The laser beam is propagated on a surface and collected by a sensor. The laser travel time between propagation and reception gives the surface scanner geometric information.
3D scanning technologies
- Laser triangular 3D scanning technology
- Structured light 3D scanning technology
- Photogrammetric 3D scanning technology (photography)
- Contact-based 3D scanning technology
- Laser pulse-based 3D scanning technology
Laser triangular 3D scanning technology
As you know, Laser triangle-based 3D scanners use a laser line or a single laser dot to scan an object. First, the 3D scanner launches its laser on the object. The laser light is reflected from the three-dimensional scanned object, and its original path is corrected and selected by a sensor.
It is then modified based on this path, and thanks to trigonometric relationships, the system can detect the angle of deviation of the laser. The calculated angle is directly related to the space from the thingto the scanner. When the 3D scanner contains enough distances, it can map the object’s surface to reconstruct it in 3D.
One of the main advantages of laser triangulation technology for 3D scanning is its high resolution and accuracy. One of the disadvantages of laser triangulation technology is that it is very sensitive to the properties of the body surface. Very glossy and/or clear and/or dark surfaces are problematic.
Structured light 3D scanning technology
Structured 3D light scanners use trigonometry but do not rely on lasers. Instead, they spread a series of linear patterns on the object. The system can then check the edges of each line in the pattern and how the lines deform and calculate the distance from the scanner to the surface of the object.
The projected structured light used for 3D scanning can be white or blue and can be produced by various projectors, such as Digital Light Processing (DLP) technology. The predicted pattern is usually a series of light rays, but it can also be a random-dot matrix.
One of the main advantages of structured light technology for 3D scanning is its speed and sharpness. And its non-harmful light can be used for 3D scanning of the body. However, structured 3D light scanners are sensitive to light conditions and have difficulty working outdoors in broad daylight.
Photogrammetric 3D scanning technology (photography)
Photogrammetry is the science of measuring photos, especially to retrieve the exact position of surface points. Photogrammetry is based on computer vision and powerful computational geometry algorithms.
The principle of photogrammetry is the analysis of multiple images of a stationary subject taken from different perspectives and automatically detect pixels corresponding to a single physical point.
The main challenge of this 3D scanning technology is to examine tens or hundreds of images and thousands of high-precision dots. To run such photogrammetric algorithms requires a very powerful computer.
The main advantages of 3D photogrammetric scanning technology are its acquisition speed and ability to select colors and textures. Photogrammetric technology can also reconstruct subjects on a large scale, such as landscapes or buildings photographed from the ground or the air, for example, by a UAV.
The quality of the results produced by photogrammetric technology depends on the resolution of the input photos. This technology can also be very slow, depending on the software and settings of your PC.
Contact-based 3D scanning technology
Contact-based 3D scanning is also known as digitization. This 3D scanning technology includes a contact-based form of 3D data collection.
3D contact scanners examine the subject through physical touch while holding the object firmly in place. A touch probe moves along the surface to record three-dimensional information. The probe is sometimes attached to a hinged arm to collect all the relevant adjustments and angles for greater accuracy.
Some special configurations of contact-based 3D scanners are called Coordinate Measuring Machines (CMMs).
3D contact scanning is widely used to perform quality control after construction or maintenance operations. The main advantages of contact technology for 3D scanning are its accuracy and ability to 3D scan transparent or reflective surfaces. Weaknesses of 3D contact scanning technology include low speed and the inability to work with organic and free forms.
Laser pulse-based 3D scanning technology
Laser pulse-based 3D scanners, also known as flight time scanners or Lidar laser 3D scanners, measure how long it takes a cast laser to hit an object and bounce back.
Since the speed of light is precisely known, the time it takes for the laser to go back all the way shows the exact distance between the 3D scanner and the object. To accurately measure distance, a 3D scanner calculates millions of laser pulses with an accuracy of up to picoseconds (1 pics is equal to 0.00 trillion1 seconds).
Since each measurement collects only one point, the 3D scanner must project its laser 360 degrees around that point. To do this, the 3D scanner is usually fitted with a mirror that changes the direction of the laser.
Time-of-Flight 3D scanners include both laser pulse lasers and phase shift lasers. 3D phase-shift laser scanners are a subset of laser pulse 3D scanners. In addition to laser pulses, phase change systems also modulate the power of the laser beam. Phase shift lasers offer better overall performance.
How to use 3D scanning?
3D scanning, if you just reconstruct an existing object, can be a faster and easier technique for creating a 3D model for 3D printing. Once you have your 3D model, you can add changes to it, and itan actually be a great base to start your project.
What is the use of these 3D scans? The medical department really makes the most of this scanning technology. It also helps measure and crcreatesrostheses made for patients by 3D scanning. The scanning is very common in dentistry, for example, to view, simulate options, or even create dental devices such as braces, implants, and dentures. Using 3D scanning and 3D printing is great to avoid all the flaws of the templates and the whole process of creating these templates.
3D scanning has many advantages. There is even a solution for inventory data that we can use later. Did you know that some 3D scans of Notre Dame, the French cathedral, part of which burned down on April 15, 2019, could be used to reconstruct it? 3D scanning has many potentials.
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