The commercialisation of 3D laser scanners in tandem with the increasing ubiquity of Building Information Modelling (BIM) software has made advanced reality capture a highly viable option for members of the AEC sector when it comes to the precision surveying of sites and assets.
The market for 3D laser scanners is booming, with a recent report by consultancy Market & Markets forecasting a doubling in global value during the five-year period from 2013 to 2018, from $2.06 billion to $4.08 billion.
While 3D laser scanners are employed by a multitude of industries, including aerospace and defence, entertainment and media, energy, and healthcare, the advantage of the technology for business purposes are particularly demonstrable for the AEC sector, whose exclusive business is manipulation and control of the physical world’s corporeal particulars.
Today’s 3D laser scanners are capable of producing data-rich “point clouds” based on existing physical environments, that can subsequently be used to create extraordinarily detailed digital reproductions of such real world locations for various surveying or design purposes.
The scanners achieve this by using lasers mounted on rotating heads to measure the precise 3D location of myriad points on the surfaces of physical objects. They are capable of performing this process with tremendous speed and accuracy, recording millions of individual data points within the space of mere decades.
Operators of the devices then move them around to cover multiple lines of sight in order to amass point clouds that serve as comprehensive models of real world environments, that account for almost every last nook and cranny on their exposed surfaces.
While the 3D laser scanners themselves are just the tools for amassing vast amounts of raw data on the real world in the form of point clouds, it’s the widespread use of BIM within the AEC sector that has greatly expedited the use of technology for reality capture purposes by providing the software platform within which data-rich models of physical environments can be created and manipulated.
The ability to produce highly accurate and detailed digital reproductions of the real world using laser scanning technology brings multiple benefits to members of the AEC sector.
It enables them to model and visualise the actual conditions of a real world site with near-perfect accuracy, which is of immense benefit to architects during the design phase of a project, as well as during the process of selling clients on the merits of a proposed outcome by enabling it to be viewed in its actual context.
Engineers can use reality capture to create the most accurate possible form of “as-built” documentation on an existing built asset, which greatly facilitates the process of structural analysis and clash detection.
3D laser scanning can also help owners to fully leverage the benefits of BIM during the operating phase of a project by facilitating the creation and maintenance of reliable, up-to-date Asset Information Models that perfectly reflect the current state of assets.
In addition to permitting the creation of preternaturally detailed precision models of the real world, as a surveying method, laser-based reality capture is also several orders of magnitude faster than conventional techniques.
A surveyor using a total station, for example, is at best capable of measure roughly 700 points during a full day of work. Today’s 3D laser scanners make this figure seem trivial, however, as they are capable of measuring as many as a million physical points in just a second.
Laser-based reality capture is also far more accurate than conventional surveying. While a surveyor must apply their own interpretation to the process based on client needs, and can avail themselves of only limited measurement points given time and labour constraints, 3D laser scanners are capable of amassing millions of data points within the blink of an eye, as long as the surface of an object lies within the device’s line of sight.
3D laser scanners are just one of many technologies that are currently being used for reality capture purposes, with other popular options including structured light sensors and photogrammetry, as well as more esoteric tools such as X-rays, ground-penetrating radar, and impact echo-testing.
Laser scanners possess a number of advantages compared to their main rivals in the reality capture space at present. Chief amongst them is the extremely high data density of laser scanners, which enables them to achieve extraordinary levels of accuracy
Terrestrial survey-grade scanners can accurately record points that are just millimetres apart, particularly when effective survey techniques are employed. This makes them extremely accurate tools for reality capture purposes, which is of critical importance to complex engineering and design projects where precision is of paramount importance.