use of 3d laser scanning in singapore
Around the turn of the 21st century, 3D laser scanning techniques were developed for various uses such as: 3D digital measurement, documentation and visualization in many fields, including; construction, heritage conservation, facilities management, oil and gas industry, geospatial and survey industries, architecture, processing and mining industries, building infrastructure and archaeology. Increased innovation in hardware and BIM software performance have created improved applications of scanning technology for the building and construction industry. Scanning of objects is commonly applied to existing building structures. 3D model acquisition produced from laser scanners and photogrammetry provide content-rich information of the as-built conditions. The top manufacturers of 3D scanners are of the opinion that scanning technology will become a critical function required to complete the integrated BIM cycle efficiently and provide obvious value additions for the integrated BIM workflow.
use-case scenarios for scan to bim
BIM is a digital data flow around the lifespan of an asset or element of the built environment, proposed to provide better information management to aid with decision making. As a process, BIM has gained improved global acceptance across the Architecture, Engineering, Construction and Operations (AECO) community for improving information sharing about built assets. An important component of this is an object-based 3D parametric model which holds both geometric and semantic information. Other related BIM tools can be used to obtain useful details for various purposes. The captured 3D building model serves two purposes:
Energy analysis in construction
For Energy Analysis before, during and after reconstruction, when the chosen type and/or variant of insulation solution is applied. This allows fast and seamless assessments of design solutions to arrive at the most energy-efficient solution.
generate realistic site conditions (in bim) for assembly of prefabricated components
Many project sub-contractors are very sophisticated in their ability to create physical work assemblies in off-site locations and then bring them on-site in large clusters for rapid installation. Prefabrication offers many benefits, including safer working conditions, controlled environments, and automated machine usage. However, prefabrication is only successful when it is utilised in combination with accurate information about the destination of the final installation, which laser scanning can provide quickly.
scan to bim workflow
Creation of an as-built BIM involves measuring the geometry and appearance of an existing facility and converting these measurements into a high-level, semantically rich 3D model representation. The creation of as-built BIM model mainly involves three tasks: modelling the geometry of the building elements, assigning an object category and material properties to elements, and establishing relationships between elements.
1. Geometric modelling
The task of geometric modelling is to capture a representation of the building elements by fitting 3D geometric primitives to the point cloud data. Geometric primitives have to be individual volumetric shapes, e.g. a simple wall can be modelled as a rectangular box (cuboid). Since BIMs are normally defined as solid shapes, surface-based representations if present are required to be transformed into solid models of corresponding building elements. Capturing of parametric elements in external modelling applications depends upon the outcome of desired scope. Depending on the degree of fidelity of the model, several levels may be distinguished. In a low-fidelity model, rooms or spaces are modelled as simple solid volume geometric masses. Medium fidelity models are made from internal walls, floors, ceilings, and doors, etc. High-fidelity models asides the former include detailed door and window openings, building elements, detailed thermal bridge elements, MEP etc. Within each room or space permanent fixtures may be represented, such as sinks, toilets, urinals, lighting fixtures, etc.
2. Formation of as-built model
The forming of as-built model is a process of creating objects that represent building elements, including both geometric and non-geometric attributes and relationships. If BIM is modelled on the basis of previously captured building information, the preceding data capture, processing, and recognition methods influence data quality through the deployed technique and the provided level of detail. This was a complicated process in the earlier period of the development of these technologies. However, now, numerous plug-ins or add-on software modules have been developed, so that it is possible to import and process large scanning data files directly into BIM authoring software (i.e. Revit).
In addition, many hardware producers now are trying to attract more customers, allowing their proprietary data formats to convert into a neutral or unprotected file format e.g. ASCII format. This makes post-processing in independent software applications possible.
3. model export to cad
To choose an appropriate data export format, one should consider which CAD software will be used in downstream workflows. Most of the popular CAD and BIM software packages e.g. Autodesk AutoCAD, Autodesk Revit, Graphisoft ArchiCAD, and Bentley AECOsim Building Designer, allow direct import from scanners like Faro, Trimble or Leica using different data formats. These formats include xyz coordinates of the points, RGB colour and point intensity.
The only challenge is to follow the never-ending software version upgrades which for CAD software traditionally occurs annually. When considering the application of special add-on or plug-in products from third party developers, it is important to look out for compatibility issues. A well documented module may not even work with a newer or older version of end user software it was originally developed for.