The practice of BIM (Building Information Modelling) delivers more intuitive and cohesive collaboration on construction projects, improving efficiencies in the process. Now, advances in point cloud registration technology are expanding the possibilities of BIM in the construction process and beyond.
BIM is a process for creating and managing digital representations of physical spaces — a data model of a building or asset that enables an improved workflow for those working with it. The premise underlying BIM is that datasets of a building project should not only represent the three dimensions of physical space (height, width, and depth) but include other characteristics of the building such as time, cost, and functional details. Including this kind of information in a model aids the design and construction processes and future maintenance of the building.
The UK government categorises BIM as Level 0-3. Level 0 refers to the computer-aided designs (CADs) architects began using in the 1980s. BIM Level 1, ‘object-oriented’ CADs, appeared in the early 1990s, introducing 3D modelling and greater automation of tasks such as scheduling and room numbering.
BIM Level 2 adds a further goal to enhance workflow. This is to facilitate collaboration by ensuring that a change to one part of a project’s data is coordinated everywhere else. Architects, engineers and builders each need to view and change parts of the same dataset in different formats. When any change is made, it needs to be reflected in all of the separate representations. In BIM Level 2 this process is improved by the use of common export formats and the creation of a ‘collaborative data environment.’
While BIM levels 0-2 essentially offer an increasingly convenient digital version of traditional planning and model-making for building projects, BIM Level 3 represents a conceptual innovation. This category of BIM remains partially undefined. However, BIM Level 3 will be used here to reference modelling that pulls design and functional characteristics into central database storage. Storing all the information in a central database, rather than beginning with graphical representations, drastically improves workflows. Regardless of how the data is represented in various formats, it is stored in a single place. Any change of the data is automatically reflected everywhere else. This way all members of a team might share and edit files. BIM Level 3 is the technology platform we will be the focus of this article. Point cloud technology is expanding and enhancing the possibilities of BIM.
BIM provides everyone with access to the data in the format they need without the necessity to duplicate it. Rather than requiring separate updates when something is edited, with BIM, changes made in a given format are automatically updated throughout. A substantial amount of time is saved by removing the need to cross-check files.
Storing the data centrally allows for documents such as diagrams and schedules to be created and distributed easily. The same applies to 3D models and simulations with which designers, engineers and builders can consult and experiment. This could include design details of a room, installation fixtures or how the sunlight looks at different times of day. Structural physics programs can be applied to test the integrity of the plans in various situations, allowing for safer buildings while also enabling the use of experimental materials and construction techniques. The accessibility of 3D models allows non-specialists to engage with structural and architectural designs, improving client experiences and empowering construction teams.
BIM schematics remain useful long after the construction is completed. Maintenance, repairs and renovations are made easier and more effective with the precise details of the database, which can be updated for continued operations, further improving efficiencies.
The next major step for BIM is to go beyond the realm of theory and into physical reality. The BIM concept has traditionally been limited to planning and building new structures. However, terrestrial scans and point cloud processing can be used to create a BIM database of an existing building.
Building managers that oversee the maintenance of a building constructed with the aid of BIM get the advantage of a pre-constructed central database of their facilities capabilities. Now point cloud technology offers the ability to create such a model for any structure, no matter when it was built. With older buildings especially, crucial information and documentation concerning infrastructure, piping, electrical systems and maintenance history is scattered or even nonexistent. Point cloud scans allow you to quickly build a database from scratch.
Building managers can view their facility in 3D models and are able to filter the information to reflect specific relevant categories. Work teams can be more easily directed, and any obstacles or hazards can be identified and prepared for. This makes any type of building maintenance, from simple repairs to advanced analyses (such as thermal and x-ray) easier and more efficient. In addition, newer technology for structural maintenance such as airborne sound analysis require digital models to use. BIM provides a ready-made platform to implement these types of proactive maintenance procedures that are improving the efficiency of all types of building and facility management.
Post hoc BIM databases are only as limited as the information extant. Some details concerning design standards, building codes, construction methods and materials of old or historical structures may be unavailable. However, precise 3D models that include some of the details that would be included in a ‘design first’ BIM have been made. Point clouds allow surveyors to guarantee the accuracy of the spatial data they produce for post-hoc BIM schematics.
Point cloud technology offers major benefits to the construction process as well. Ensuring that projects align with plans is a necessity for builders. Point cloud technology produces accurate scans of construction sites before, during and after construction that can be compared to BIM plans at every step. The ability to produce a three-dimensional model at each stage of a project before proceeding allows teams to progress according to plan with confidence that errors have been avoided.
The application of scanning technology to augment BIM schematics or create BIM style 3D models of existing structures has always been limited by the cost of point cloud surveying. The creation of point clouds was inefficient due to the time-consuming nature of 'registration'. Point cloud software could not produce reliable alignments automatically, requiring technicians to manually input and cross-check each and every alignment. Fortunately, targetless registration for point cloud datasets is now efficient enough to make its use in BIM construction projects feasible.
The solution has been delivered by a new process of multi-stage vector analysis. In the new targetless registration process, point clouds are represented as 'vector spheres', which enables them to be automatically compared and aligned, drastically cutting down the need for manual oversight. By breaking the registration process into three alignment stages (rotational, horizontal and vertical) greater automation is achieved and processing time cut by 40-80%. This also allows rapid comparison of entire data sets, resulting in more accurate alignments than before.
These improvements are revolutionising the possibilities for point cloud scans. The increase in efficiency created by automated, multi-stage processing is allowing new businesses and industries to take advantage of point cloud technology.
The practice of Building Information Modelling (BIM) ensures that datasets include relevant information about a building project beyond just the physical dimensions of the building. Models created from BIM data are invaluable to the construction of the building and later maintenance and management. By centrally storing these datasets, various team members are able to make changes in the data which are reflected throughout, no matter what format the data is being accessed in.
Laser scanning and point cloud technology can be used to make accurate models of areas during construction and after to deliver excellent BIM datasets. At every stage of construction, a 3D model can be made to ensure a project aligns with the plan. Scans of existing buildings can be taken to create BIM datasets for buildings that lack them, allowing vast improvements of visibility and planning capabilities for management and maintenance. The maturation of point cloud technology is increasing its accessibility by improving the efficiency of point cloud processing. This is allowing new types of projects and building managers access to this resource. Point clouds and BIM are a powerful combination.