One of the newest and most exciting developments in Building Information Modeling (“BIM”) is the use of point cloud laser scans to create detailed 3D images of those structures. Imaging specialists use software from companies such as Autodesk Revit to generate images of anything from individual features of a building to entire city blocks from a set of data points in a 3D coordinate system (i.e. a “point cloud”). Those images can be integrated into a BIM system to simplify and to unify efforts toward the planning, construction, and operation of mechanical systems in new buildings, and to create images of existing buildings to facilitate installation of updated mechanical systems or retrofits and repairs of existing systems.
In practice, the laser scan that creates the data that is fed into a point cloud is analogous to the motion capture technology that is used by video game designers and movie animators. That technology reads motion data from a number of sensors on a special suit worn by actors and translates that motion into an animated character. With point cloud scanning and BIM technology, a scanning company will use one of several laser scanning options to create the data, including High Definition Surveying (“HDS”) and LiDAR The final laser scanning choice will be a function of the desired speed, accuracy, and range of data that needs to be generated to create the desired 3D images. In practice, the laser will be targeted at a structure and a data point will be generated for each time the laser reflects off of a point in three-dimensional space. The most robust laser scans will generate millions of data points per second.
A scanning company will take multiple scans from several different perspectives to generate an extremely dense data cloud. The distance between data point scans on the surface of a structure can be as low as two or three millimeters, which accounts for that data density. The company that conducts the scan will know the correct point density to create the image that has the greatest utility for architects, designers, and engineers.
The problem at this stage of the process is that few AEC firms have the internal technology or expertise to translate the massive amount of point cloud data into useful 3D images. Without proper point cloud functionality, the best result that can be drawn from this data is a 2D intermediate result with limited modeling references. The 2D image, however, creates a risk of losing data from the 3D laser scan. When a 2D image is later re-translated into a 3D digital model, that lost data will create modeling flaws that can affect the progress of a building project. An AEC firm might overcome this problem by transferring scan view data into a third-party software product that is able to interface into a BIM system, but this process is time-consuming and expensive, and it adds substantial unnecessary costs and delays into a building project.
A specialist scanning company that supports the AEC’s BIM modeling efforts adds the greatest value at this stage of the process. The scanning company’s specialists will analyze point cloud data to eliminate noise and to assure the integrity of the remaining data set, and will then use that set to generate meshed or surface 3D images that are integrated directly into the AEC firm’s BIM system. Architects and engineers then have direct access to those images for planning, detecting clashes and conflicts among mechanical system pathways, providing virtual reality tours of a planned or existing structure, or producing technical documents for regulatory, administrative, and operational purposes.
Older scan-to-BIM technology was limited by its ability to detect and model fine detailed features in a structure and to distinguish among different objects that are integrated into a structure. Two innovations in point cloud scanning from IMAGINiT Technologies have addressed these limitations, and in the process they are opening new vistas for designers, remodelers, and building preservation specialists. The first innovation is a “Create Mesh” feature that facilitates the modeling of finely-detailed building structures. Without this tool, building modelers would spend hours or days to create digital models of detailed building structures such as steeples, sculptural ornamentation, and ornate facades. The Create Mesh functionality creates a digital model in a matter of minutes by organizing and rendering scan data from a point cloud data set. The software allows designers to zoom in and out of different details in the structure with a simple slide bar control.
The second innovation is an “Auto-Find Walls” feature that eliminates the need to model building walls one at a time while simultaneously detecting different objects that are integrated into walls (e.g. bump-outs, windows, etc.). This feature renders a building or structure model from a point cloud data set, then gives architects and engineers a robust set of options to select different portions, levels, or tiers of the model with sufficient detail to distinguish walls from other surface areas. This feature also analyzes point cloud data to identify the materials that were used to build the wall. Thus, an architect or engineer can see whether a wall is made of brick, stone, wallboard, or some other material with a simple click of a computer mouse. It also distinguishes floors and ceilings and translates everything into an Autodesk Revit image with another mouse click.
The value of these features is best illustrated with an example. Assume that an AEC firm is tasked with modeling an existing structure for renovation and preservation. Unlike newer structures, the existing structure may have sagging or deformed walls and other features that pose a real challenge to more traditional modeling technologies. If the AEC firm were hired only for facilities management purposes, those deformities would not be a problem and a more generalized building scan would produce a usable digital model for the management function. Alternately, if the AEC firm was asked to provide an opinion of the building’s structural stability or to develop a conservation plan for its structures, the general scan would overlook crucial details. A detailed point cloud scan to a BIM system would quickly and accurately replicate all important details that the architects would need to complete the project.
AEC firms are typically concerned with three issues when they outsource the scan-to-BIM function: quality, cost, and risk reduction. Quality is a legitimate concern, as point cloud scanning to BIM is a relatively new technology, and only a few scanning companies have developed the depth of expertise to produce and render the detailed scans that the AEC firms need. Cost is also a major concern, but few AEC firms have the budget or resources to develop this expertise in-house, and outsourcing this function will be the more efficient and inexpensive option in virtually every case. Risk reduction is a concern at every stage of a project, but risks can be controlled and managed with good quality 3D drawings that show the detail needed to avoid the problems which arise when risks are not accounted for properly.
The Engineering Design Company has the expertise and ability to satisfy these concerns in every capacity. We provide scanning and modeling services for all types of building projects and have the experience and technology to handle everything from small, single-structure scans to the imaging of entire city blocks. We are available on a 24/7 basis to help AEC firms meet all deadlines with high-quality 3D images and within all budgetary constraints.