The disadvantage of CMMs is that their upfront cost and the technical knowledge required to operate them.
The greatest advantage of a CMM after accuracy is that it can be run in autonomous (CNC) mode or as a manual probing system. CMMs are the most accurate form of 3D measurement achieving micron precision. Modern CMMs are 5 axis systems, with the two extra axes provided by pivoting sensor heads. As the touch probe moves around the part, sensors on each axis record the position to generate XYZ coordinates. Coordinate measuring machines (CMMs) which traditionally have 3 perpendicular moving axis with a touch probe mounted on the Z axis.There are two main types of contact 3D scanners: There are a variety of technologies that fall under each of these categories.ģD scanning of a fin whale skeleton in the Natural History Museum of Slovenia (August 2013)Ĭontact 3D scanners work by physically probing (touching) the part and recording the position of the sensor as the probe moves around the part. Non-contact solutions can be further divided into two main categories, active and passive. A well established classification divides them into two types: contact and non-contact. The techniques work with most or all sensor types including optical, acoustic, laser scanning, radar, thermal, and seismic. There are a variety of technologies for digitally acquiring the shape of a 3D object. This whole process, going from the single range map to the whole model, is usually known as the 3D scanning pipeline. These scans have to be brought into a common reference system, a process that is usually called alignment or registration, and then merged to create a complete 3D model. Multiple scans, from different directions are usually helpful to obtain information about all sides of the subject. In some situations, a single scan will not produce a complete model of the subject. This allows the three dimensional position of each point in the picture to be identified. The "picture" produced by a 3D scanner describes the distance to a surface at each point in the picture. While a camera collects colour information about surfaces within its field of view, a 3D scanner collects distance information about surfaces within its field of view. Like most cameras, they have a cone-like field of view, and like cameras, they can only collect information about surfaces that are not obscured. If colour information is collected at each point, then the colours or textures on the surface of the subject can also be determined.ģD scanners share several traits with cameras. These points can then be used to extrapolate the shape of the subject (a process called reconstruction). This 3D model consists of a polygon mesh or point cloud of geometric samples on the surface of the subject. The purpose of a 3D scanner is usually to create a 3D model. 4.13 Circumvention of shipping costs and international import/export tariffs.4.12 Quality assurance and industrial metrology.4.2 Construction industry and civil engineering.2.8 Acquisition from acquired sensor data.2.7.1 Photogrammetric non-contact passive methods.Other common applications of this technology include augmented reality, motion capture, gesture recognition, robotic mapping, industrial design, orthotics and prosthetics, reverse engineering and prototyping, quality control/inspection and the digitization of cultural artifacts. These devices are used extensively by the entertainment industry in the production of movies and video games, including virtual reality. For example, industrial computed tomography scanning, structured-light 3D scanners, LiDAR and Time Of Flight 3D Scanners can be used to construct digital 3D models, without destructive testing.Ĭollected 3D data is useful for a wide variety of applications. For example, optical technology may encounter many difficulties with dark, shiny, reflective or transparent objects. Many limitations in the kind of objects that can be digitised are still present.
The collected data can then be used to construct digital 3D models.Ī 3D scanner can be based on many different technologies, each with its own limitations, advantages and costs. 3D scanning is the process of analyzing a real-world object or environment to collect data on its shape and possibly its appearance (e.g.