3D scanning is a type of reverse engineering that uses light or contact to create a 3D image of a solid object. This image can then be digitally saved, edited, or used directly in 3D printing production. Currently, there are various 3D scanning technologies available, ranging from small tools and parts, medium-sized human limbs, and large vehicles to landscapes, each with different applications. Below is a brief explanation to help you understand them!
Basic concepts
During the 3D scanning process, the 3D scanner can gradually build up a digital image of the target object, and the scanning results are usually compatible with CAD design software and 3D printing programs, so that they can be directly modified or used to produce 3D printed entities.
Application Category
Modern 3D scanners are widely used in automobile manufacturing, aerospace, dentistry, artifact preservation, and game characters, among others, with film and television special effects and VR virtual scenes experiencing particularly rapid growth. Based on different construction principles, 3D scanning technology can be mainly divided into contact and non-contact 3D scanning :
I. Non-contact scanning
Time of Flight (TOF)
"Time-of-flight ranging," also known as "time-of-flight ranging," primarily uses laser light to detect targets and then calculates the surface image of the object by measuring the round-trip time of the laser light. Since each laser signal can only measure one endpoint, it is usually equipped with a rotating mirror to allow for 360-degree scanning of the object.
Features and limitations: "Time difference ranging" can measure approximately 10,000 to 100,000 target points per second. It is mainly used for large industrial objects and fields with high accuracy, but its speed is relatively slow compared to other 3D scanning technologies.
Laser Triangulation
As the name suggests, the "triangulation method" refers to the use of a laser spot on an object, a sensor, and a laser to form a triangle. The laser light is emitted onto the object being measured, and the sensor records the reflection time and deviation angle of the laser spot, thereby calculating the shape of the object.
Features and limitations: "Triangulation" is a 3D scanning technology with high resolution and accuracy. However, it is relatively sensitive to the surface characteristics of the scanned object and is not suitable for objects with highly reflective or transparent surfaces.
Photometric Stereo
Photogrammetry (or "stereo optics") works by analyzing still photographs taken from different angles and automatically detecting the corresponding pixels. Due to the large amount of information, it requires calculations by a high-powered computer.
Features and limitations: Photogrammetry is well-suited for large-scale applications such as terrain models or aerial photography. However, its drawbacks include lower resolution for details and longer processing time.
Structured Light 3D Scanning
Linear patterns (or "gratings") are projected onto the object being measured, and the surface shape of the object is calculated by observing the deformation at the edges of the grating. The light source is usually LED white or blue light, making it widely used for human or facial imaging. Some 3D scanners can also read color images; these full-color scanning aids are often called "texture cameras." Because they can measure multiple points or large areas at once, they are generally divided into two methods: fixed 360-degree scanning and handheld fast scanning. (Further reading: EinScan Pro 2X+ put to the test! Bumper modeling in just 3 minutes! )
Features and limitations: Structured light 3D scanning strikes a balance between speed and image quality, and handheld scanning is relatively simple, making it a widely used technology. However, this technology is quite sensitive to ambient light, therefore it is more suitable for indoor use. For outdoor environments, scanning is recommended on cloudy days without strong sunlight. (Further reading: Reverse engineering tests, monsters and their models! )
II. Contact Scanning
• "Contact-based 3D scanning "
The method involves physically probing an object and using a probe to move across the surface to calculate a 3D image. This can be imagined as a calculation method that uses a pen to draw a three-dimensional structure.
Features and limitations: While contact 3D scanning offers high accuracy and is almost unaffected by lighting on the object's surface, it is only suitable for small to medium-sized objects due to its speed limitations. As it is limited by physical contact, it is not suitable for fragile ancient artifacts or works of art.
Time difference ranging: Depicting the geometric data of an object by measuring the round-trip time difference between the transmission and reception of a laser beam.
Triangulation: Projecting laser light onto the surface of an object and measuring the laser angle data to convert it into a 3D image.
Photogrammetry: Reconstructing images in 3D from a large number of overlapping 2D pixels using computers and visual images.
Structured light: Based on the deformation of an object caused by a grating, 3D scanning imaging is constructed, usually using an LED light source.
• Contact scanning: relies on physical multi-point sampling of the entity and uses the contact trajectory of the probe to build an image.
After this introduction, do you have a better understanding of 3D scanning ? Unsure if your 3D scanner meets your needs? Feel free to contact us for answers, or we also offer high-quality scanning services.
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