How to create Digital Twins for Heritage and Conservation…
I will liken him to a wise man, who built his house on a rock. The rain came down, the floods came, and the winds blew, and beat on that house; and it didn’t fall, for it was founded on the rock.
If you grew up attending Sunday school as I did, you’d find this parable in the book of Matthew familiar. The same can be said for Digital Twins, building a foundation with accurate information guarantees higher chances of success.
With that in mind, Congratulations! You’ve strapped on a pair of boots, picked up a LiDAR scanner and digitised the site you intend on converting into a Digital Twin. You’ve just taken your first step in preserving history in the Metaverse — now what?
The output of LiDAR scanning is a super accurate point cloud that enables measurements between objects with confidence. However, it doesn’t take long to realise that point clouds have limitations….
- File Size (can be in the Gigabytes!)
- Functionality (can I do anything else, besides measure stuff???)
- Unstructured data (can I assign information to the points?)
The issues described above can be overcome by converting point cloud to building information modelling (BIM), a process also known as scan-to-bim.
Similar to using tracing paper as a kid to replicate drawings, the process involves using a point cloud as a reference and tracing over the top of the point cloud with BIM elements.
The creation of the BIM model for the NUS Baba House was completed in less than a week. Using a combination of photography and LiDAR the team at TwinLogic Pte Ltd, accurately converted the raw information into a useable BIM model.
Why BIM and not the other formats? — The answer is plain and simple, BIM has an underlying data structure that describes what an object is and its relationship to other objects in that space. It is one of the few languages a machine understands.
In a BIM model a door is a door and information is tagged to it. No auto recognition, no guesswork, no problems.
Other benefits of the BIM model include-
- significantly smaller file size (megabytes, not gigabytes, easy to share)
- structured data taxonomy (enables queries, aggregation and analysis)
- useability (widely adopted data formats)
Converting the LiDAR and photography information into a BIM model has provided the team at the National University of Singapore with an accurate, structured baseline to build future applications upon. So stay tuned, we’ll let you know where it's headed.
On top of everything that has already been mentioned. BIM is an established data format used in Architecture, Engineering and Construction, BIM files can be turned over for future retro-fitting works without having to re-survey the space. BIM here is to stay and will not so easily go out of fashion.
