AEC Firms are increasingly utilizing point cloud models obtained from laser scanned data and using them for BIM, especially for building renovation and retrofitting projects.
Aug 12, 2014 -- Point cloud, an emerging technology, is a marked interest amongst architects these days. Entire buildings are replicated into a point cloud model by taking multiple scans using several High-End laser scanners that measure millions of points across a buildings surface, and provide detailed demarcations and dimensions. Buildings are scanned in entirety or in parts depending upon the requirement of a renovation project. This scanned data is delivered to 3D modelers who build on this data to develop BIM 3D models.
Point cloud to BIM – How much is too much?
The other side to this is that, people now want to use point cloud for every renovation project, without analyzing the requirements.. At times a building or a part of a building that needs to be renovated can be surveyed using traditional methods, and further BIM models can be created based on these surveys. However, in such cases stressing over point cloud scanning can amount to unnecessary overheads and massive scanning costs.
Point cloud is popular; however, there is a lack of understanding of what point cloud actually is and what it can offer. When you collect point cloud data, the volumes can be massive. If an entire building is to be renovated, then it might require as many as 200- 300 scans or even more. Here, BIM experts are supposed to be adept enough to handle these huge data volumes, and surface reconstruct point clouds to build BIM models with high level of detailing.
What is a point cloud model?
A point cloud model is a set of millions of data points within a coordinate system. These points represent the outer surface and the shape of an object. However, a point cloud model cannot be used as a BIM model. This point cloud data is used as a reference, and BIM experts trace upon this data to reconstruct a 3D model that is ready for BIM.
BIM experts index point cloud data from the photometric images and further use surface reconstruction technique to build a 3D model with triangles, polygon meshes or nurbs as per the project requirement. Further BIM specialists set up sections, elevations and levels to create 3D models that are ready for BIM.
Experts use software tools like Autodesk’s Revit BIM, to build a fully parametric building information model from the point cloud data. Using point cloud to BIM technology makes it possible to compare new building designs with the existing conditions. Experts can also compare as planned designs with as built structures, hence easily identify and analyze the possible issues in a renovation or a refurbishment project.
With the growing demand for refurbishment and renovation projects across the AEC industry, Point cloud to BIM technology is getting the required mileage. Almost every CAD service provider is bracing up, upgrading resources and leveraging capabilities for catering to the Point cloud to BIM requirements of clients.
How to choose your BIM expert?
Anybody who promises Point cloud to BIM at the best price might not necessarily be the right choice for you. Before engaging a BIM modeler, it is important to know about all the project related details, like what software will be used to create a BIM model, what will be the Level of detailing offered and whether the modeler has the capabilities to load the 3D BIM model with further information for project scheduling, cost estimation, sustainability, facility management etc?
Any technology is only as good as the quality of equipments and more importantly the ability of people using it. Hence, there are full chances of inconsistencies in point cloud data.
BIM models are intolerant to any kind of clashes or interferences when it comes to a building’s geometry. BIM specialists identify all the building elements like walls, stairs, doors, windows and floorings that are out of alignment in a point cloud model, and rectify these errors when they trace the point cloud models can convert them into 3D BIM models.
Laser scanning tools like Lecia Cloudworks and Kubit can fetch point cloud data that can be directly imported into Revit. These point cloud models are partially BIM ready; however, BIM modelers still need to put in a lot of dedicated efforts in rectifying and surface reconstruction for these models in order to make them fully ready for BIM. Hence, whatever scanning tool you use the importance of an expert and experienced BIM modeler cannot be underplayed.
About Author: Nikunj Patel is a design engineer working with Hi-Tech CADD Services for the past 4 years. He loves designing specialized industrial equipments and can always be found in the lab discussing, brainstorming & tweaking designs. He has also worked on architectural projects taking interest in every aspect of design & analysis.