Research, Documentation, and Restoration of Singapore's Built Heritage through 3D Modelling
Funded by the Ministry of Singapore's Academic Research Fund (AcRF) Tier 1 Grant (October 2021 to March 2023), Dr Nikhil Joshi is leading the research in the Architectural Conservation Laboratory, which investigates the use of advanced 3D and nanotechnologies for the conservation of historic structures.
This research explores the possibility of using advanced technologies such as 3D scanning, 3D modeling, and 3D printing to document, research, and restore architectural elements of varied scales and materials. This project also explores a suitable application of nano-coating that is anti-staining, UV-resistant, and resilient to prolong the lifespan of the 3D printed elements. Highly transparent and UV-resistant super-hydrophobic nanoarrays of ceramic-encapsulated metal-oxide nanomaterials dispersed within polymeric matrices will be investigated as potential nanocomposite coatings to protect and preserve 3D reproduced architectural elements and to prolong their lifespan.
Using NUS-Baba House as a case study, this study investigates ways to document the condition and repair by reproducing architectural details, slowly deteriorating. Furthermore, the documentation of heritage archetypes derived from the 3D scanned data of various architectural features is currently building an open-source digital library of historic building elements for future presentations to a broader audience.
Overall, this interdisciplinary study by researchers from the Department of Architecture, and Department of Built Environment of the College of Design and Engineering, NUS, attempts to integrate contemporary technologies and heritage conservation, ensuring a greater appreciation of the tangible past and its preservation for future generations.
Meet the Team
Digital Restoration of NUS-Baba House with 3D Scanning and 3D Printing
Through the use of high resolution LIDAR scanning, a portion of an architectural facade ornamentation was processed in a 3D software and prepare it for 3D printing. However the first print was too faint, as seen in Progress Report 1.
Coupled with historical research and analysis, the team worked on deciphering the various visual elements in the panel in its existing condition. This process allowed for several motifs to be reconstructed. The reconstruction was eventually printed in 1:1 scale and joined.
Identification of visual elements in panel
Scanned 3D of Buddha Hand Motif
Reconstructed Buddha Hand Motif
Reconstructed panel after analysis
Parts printed in 1:1 scale and joined
Subsequently, several Material Casting Tests were conducted with different materials for one motif - the Buddha Hand Motif to assess the feasibility of this method being applied to the entire panel.
These tests were done by developing a reusable mould and filling in castable mortar of different compositions (of lime and cement base mixtures). Certain mechanical properties were tested for outdoor environmental conditions, such as strength, degradation, and breakage points.
The team also conducted experiments to analyse the composition necessary for a weather-proof special paint mix. The paint samples were also subjected to ultraviolet (UV)-visible spectroscopy to observe the reflectance of UV light. It was evident that the tiles coated with special coating material performed better.
The final step involved fixing the 3D printed panel over the top of the actual panel at NUS-Baba House. Magnetic fixtures were used after discussions on how to best approach without damaging the original panel.
Moulds of the Buddha Hand motif
Fixing of 3D printed panel onto original
Paint analysis and experimentation
Work-in-Progress of panel with 1:1 3D printed parts and special coated paints
Kua Harn Wei, Abhimanyu Goel
The team carried out high resolution 3D scans of the chosen architectural motif within NUS-Baba House, specifically, it was a panel situated within the airwell of the shophouse. Special factors like the 3D scanner's proximity and the lighting conditions were taken into account. A relevant 3D software was used to stitch the scans together. A test 3D print was also created using high-quality scanned mesh.
The next step after obtaining a high-quality 3D scan is to examine the various surfaces with various paints for improved workability, cost, and time. Different 3d polymer tiles are produced by FDM (Fused Deposition Modeling), SLS (Stereolithography), and SLA (Selective Laser Sintering). Three paint types that are frequently used in the heritage industry are tested on the three different surface types. These paints come in three varieties: natural, mineral silica, and acrylic-based. All of the samples were tested against a UV Accelerated Weather Test machine using a combination of surfaces, paints, and specialty coatings.
High resolution LIDAR scanning
Scan processing in 3D software
3D printed panel based on scan
Paint types and samples
When natural paints were combined with lime putty, cracking and fading were seen. Natural paints fade more quickly than acrylic paints. If priming is not utilized, cracking may appear. While porous surfaces require a base coat to hold some paints, polymer surfaces can use acrylic without one. Testing are done on various compositions. Experiments are still ongoing to make new findings and results.
1. Continue testing different substrate, paint, and coating combinations to find the ideal one.
2. The historians will receive 3D models for an additional examination of the Baba House's architectural themes.
3. The finished 3D model will be printed according to the required dimensions.
4. The completed 3D model is coated and painted.