3D Laser scanning services & As-Buit Surveys
We rebuild the geometry of elements and infrastructures using 3D laser scanner technology
Structured / projected light scanner
Projected or structured light scanning technology is an advanced technique that has gained significant popularity in the 3D scanning industry due to its speed and precision. This method involves projecting structured light patterns onto the surface of an object and then capturing the shape and depth of the object based on how these light patterns deform on the surface. This approach stands out for its efficiency in acquiring highly detailed 3D data compared to other scanning techniques.
It is an appealing choice for applications that demand efficiency and speed in acquiring precise three-dimensional data, particularly valuable in industries such as manufacturing, reverse engineering, architecture, and product design, where rapid and accurate capture of 3D geometry is essential for the development and production process.
In summary, projected or structured light scanning technology has become an essential tool in the field of 3D scanning, especially in environments where light reflection poses a challenge, and where quick and precise 3D data acquisition is required.
Data collection:
This technology works by flashing a grid pattern of light on an object, where it is distorted according to the topography or shape of the element. The distorted pattern is then reflected in the scanner, where it is measured.
Each flash of light provides XYZ points or polygons. As an object is scanned from several angles, the data of the different flashes are merged using mathematical models to create a digital model.
The processed scan data, in the form of a cloud of points or mesh, can be used for a number of applications, including measurement, visualization and animation, digital archiving and 3D printing. It can even be used to make a lost wax casting process in which an STL model of the object is created and printed in 3D in wax, which is then used to melt the object into other materials.
Utility and employment:
3D structured light scanners are a flexible tool for scanning a wide range of objects in different sizes and shapes. Ideal for:
-
Highly detailed organic surfaces
-
Fragile objects that cannot be physically touched by a measuring device.
-
Volume scanning: can be automated to scan at high speed.
-
Document architectural and industrial elements to be incorporated into BIM (Building Information Modeling) platforms
The type of structured light scan you should use will depend on other surface features, such as reflectivity, transparency and roughness.
This technology allows museums to quickly archive their collections digitally and share them on the computer with anyone around the world.
3D scanning process:
Below we show the process of capturing information using a 3D scanner, the resulting digital model (polygon mesh / point cloud) and playback on 3D printers.
A 3D scanning system using structured light operates without the need for physical contact and consists of a projector emitting light patterns and one or several cameras. The data acquisition and analysis process is controlled by software running on personal computers, both being integral parts of the measurement system. The acquisition of 3D data is based on the principle of triangulation, using typical angles of approximately 30° for this process. The camera is calibrated and positioned relative to the projector, which projects light patterns onto the object's surface to be scanned.
To achieve optimal results, it is recommended to perform the scanning indoors or in shaded outdoor areas. Scanning surfaces that reflect light or are (semi)transparent poses challenges for any optical scanning system. Problematic surfaces include shiny metal, glass, marble, ivory, and many plastic materials. Applying a whitening spray on the surface can mitigate issues with reflections or transparency, although this solution is not applicable to all objects.
The extent of the scanned surface in each scan pass is limited by the brightness of the projector and the feasible distance between the projector and the camera. The field of view in a single scanning setup typically ranges from 30 mm to 2000 mm. The measurement depth of the system is determined by the camera's depth of field. There is an inverse relationship between resolution and depth, as larger areas entail lower resolution/accuracy because spatial resolution primarily depends on the number of samples per unit distance. Therefore, denser sampling generally leads to better depth detail in most approaches.
