The past is now in 3D!

The application of 3D technologies in cultural heritage has happened since the 1990s. However, it has only been in the last ten years, and with the development of cheaper and more powerful computers, it has become commonplace. Making 3D models of objects in museums, buildings, and archaeological features is now a key part of our practice.

While initially it was only a means of visualisation (which is still an important part of it), it is now used in analyses that help us conserve objects and gain new insights into them. In this blog, applications of 3D recording in cultural heritage are examined within the Auckland Museum, Aotearoa, and beyond.

Blog by Dr Josh Emmitt, Curator Archaeology

17197 Blue painted bowl by Auckland Museum on Sketchfab

In the Museum

Auckland Museum has been creating 3D models for nearly ten years. These have mainly been constructed with structured light scanning, which uses light patterns to measure the shape of an object (there are some very cool models in the collection; check out this one of a Moa skeleton). Thanks to the C&L Gregory Special Projects Fund, the Auckland Museum has gained the capability to create models efficiently using photogrammetry. Photogrammetry uses multiple photographs of an object to create a 3D model. Over the last year, models have been constructed of objects on display in our Ancient Worlds gallery and others from our Human History collections that are currently not on display.

The models are used for various applications, but one of the primary ones is making them a part of our collections online interface so that objects can be manipulated digitally. Have you ever wondered what the other side of an object looks like? Or underneath it? A 3D model allows you to investigate that without holding the object. The models also reveal details not visible to the naked eye. On the model of the blue painted bowl included here, click on it, press 'i' on your keyboard, then click "Matcap". This will turn off the texture and show the bowl's surface without the colour. Can you see the lines going across it? These are from when the bowl was spun on a potter's wheel!

Auckland Museum has also recorded many of its past galleries in 3D so that you can take a virtual tour of them. Check them out here.

Ahuahu 1960 by UOA Faculty of Arts on Sketchfab

In the field

Archaeologists use 3D recording in the field to record their excavation and the landscape they work in. For example, the Ahuahu Great Mercury Island project, a joint project by the University of Auckland and Auckland Museum, used photogrammetry to record the areas where they were excavating. They also used it to take historical aerial images from 1960 to construct a 3D model of the island as it was at the time. This can be compared to modern imagery to see what changes have occurred, such as coastal erosion, and to determine where archaeological sites may be at risk of being lost.

Elsewhere, for example, the Armenian-Polish Archaeological Mission – Metsamor is using 3D modelling to display their excavations more dynamically, showing the different layers of excavations that archaeologists uncovered. Archaeological excavation is a destructive act, and once archaeologists dig up a site it can’t be perfectly reconstructed to how it was before they started. While archaeologists are careful to record small details as they work, 3D models helps to create a copy of the excavation that can be referred to later as an addition to traditional photographs and drawings. The creation of a 3D model of an object has it is being excavated is also a form of conservation. Sometimes objects, especially fragile organic ones, cannot be preserved once they are uncovered, or change in shape or colour as they dry. By creating a 3D model of them it allows archaeologists to have a dynamic record of how an object was so it can be compared to how it changes in the future, such as with wooden artefacts as they dry and are preserved.

There are many more examples online, and people are constantly developing new and clever ways to present their data.

The future

3D models are now a standard part of the toolkit of heritage professionals, whether they are based in the museum, lab, or field. Creating and sharing models is increasingly easy with web and mobile applications. 3D models can potentially contribute to our gallery displays as a stand alone display or perhaps even enhance an object (for example, reconstructing a pot from only one small part). Hologram machines (also known as peppers ghosts) can let people view 3D models without needing 3D glasses or VR headsets. Where will this technology go in the future? Only time will tell, but the potential is very exciting!