Bringing Reality Capture into BIM
Although Building Information Modelling has been a hot topic for many years now, it still happens that it is misunderstood sometimes. The key to successful integration of BIM into existing workflows is recognizing that it’s not the same thing as 3D geometry. As a matter of fact, it’s much more than that and it often requires a completely different approach and organization of work.
So I wrote this article to explain the difference between 3D information and BIM and what role 3D data play in Building Information Modeling.
Third dimension vs BIM
Like I’ve already mentioned, it’s important to understand that BIM is much more complex than 3D data itself. Shape and dimension information is just one of the BIM elements. BIM involves many people, processes, phases and covers spatial relationships, quantities and properties of building components. It should be decided beforehand what information will be used by construction partners during different phases of the project- and then included in the BIM.
When 3D model becomes BIM
Let’s take a look what else apart from 3D geometry is included in BIM. If you decide to add time-related information for particular elements or the information about the sequence in which components should be installed, you will get 4D BIM. Including data about costs and materials will result in 5D BIM. We can talk about 6D BIM when sustainability information is present. Adding maintenance data and project lifecycle information gives 7D BIM.
After this short introduction, let’s go back to the basics- 3D BIM. Three-dimensional Building Information Modelling is needed to extract and generate views and information according to the needs of various stakeholders. Its visualizations capabilities enable participants of the construction process not only to see the building in three dimensions before construction even begins but also to automatically update these views along the project’s lifecycle. What is more, it helps members of the project to collaborate more effectively and even model and analyse complex spatial and structural problems. In addition to that, new and accurate data can be collected in the course of running the project and stored in the Building Information Model, thus adding the new value to predicting issues and resolving them before they even arise.
Point cloud to 3D model to BIM
Typically, the sources of 3D data used in BIM are laser scanning and drone photogrammetry.
The first method the most effective way to gather huge amounts of information inside buildings. Laser scanning point clouds are then used to automatically extract building geometry and to generate BIM model components. The end result is 3D as-built object model. The resulting model is used to compare as-built with the design and to track progress throughout the construction phase.
When it comes to point cloud obtained with drones, they give you an accurate representation of the outside conditions. Thanks to this, the design can be placed in a high-resolution model of the real terrain and surroundings even before the construction starts. Comparing these two will reveal any incompatibilities between the design and actual condition. In consequence, it’ll save time and money by eliminating the need for rework.
Not only construction projects
Let’s not forget that BIM processes are not only implemented in construction, but also in infrastructure projects. For the time being, BIM for infrastructure is not widely used. The main obstacle to using it more often are higher requirements for 3D modelling complex and diverse elements and structures. An excellent occasion to get to know more about BIM for infrastructure is InfraBIM Open, the first conference in the world concentrating solely on open infrastructure BIM, held in January 2019 in Tampere, Finland.
Find out more about the event here
What to read next
- Learn how to a create 3D map with open source GIS software, QGIS and qgis2threejs plugin.
- Interested in drone mapping software? Find out how to choose the best one.
- Find out what are the advantages of web-based point cloud viewers from this text.
