3D modelling for heritage- virtual, physical or mixed reality?
Updated: Sep 22
A virtual 3D model on a screen has the potential for a site to be viewed, explored and analysed from every angle, and the data seamlessly integrated into computer aided design systems. Such models are regularly used by surveyors, architects, archaeologists and conservationists for specific tasks often requiring specialised software to process, manipulate or augment the raw model.
They have a further drawback in that they can often be used by one person at a time, showing one perspective and generally it is harder for them to be used by a group of people where a collective understanding or interpretation is needed, especially were those people are from different disciplines with differing awareness of the technical value or limitations of such a model.
The illustrations below show the virtual 3D model of the Shali citadel in the Siwa oasis to guide the restoration programme.
The site is organic with no reference points or lines that make modelling modern sites and structures so much easier.
In such cases a physical model can make a site easier to visualise and is much more accessible than a digital model only visible in a 2D screen. It can be touched, quickly viewed from any angle and explored by more than one person at the same time.
Successful conservation projects need to bring the different stakeholders together –conservation architects, engineers, volunteers, advisers and experts from different Ministries, local and national government; and most important the community itself.
Explanations of the work needed should be accessible and understandable to all these people. Most key meetings bringing together the different stakeholders in heritage conservation are likely to occur around a table, face to face. It is a collective experience and a virtual model or diagram that needs a screen to experience, can be a barrier to the collective understanding. You may have seen how in a museum exhibit, visitors are more likely to be drawn to a physical model first and only then look to the screens to access additional information and insights. An example that illustrates how the two approaches are complementary.
From traditional model building to 3D printing
Model building is widely used by architects and planners to present new schemes. However traditional model building is time consuming and difficult if a structure needs to be set in its natural topography.
The straighter edges, the easier a model is to build. In the case of archaeological sites and conservation architecture, there may not be any straight edges.
For natural sites there is the possibility of using traditional sculpting techniques with materials such as clay. Such an example can be see in this model of the Shali citadel in Siwa.
3D printing overcomes these challenges of creating organic, complex shapes through an additive manufacturing process. With 3D printing 3D models can be created directly from a digital file (STL). Polygons can be used to create complex shapes, with ever greater numbers and smaller sizes of the faces yielding greater accuracy.
This approach can be used to illustrated natural as well as built heritage. The picture below is a 3D model of Uluru or Ayers’s Rock. Uluru is a UNESCO World Heritage Site. The rock and the setting are equally important as the area around the formation is home to an abundance of springs, waterholes, rock caves and ancient paintings; and it’s the great rock is offset by the flat, arid land around it.
Reverse spaces can be created as in this example of a cave which is another example from the 3D Creation Lab.
The challenge of water
Water features can create a particular challenge to survey as the surface is reflective and continuously moving. Blending the natural structure of the land with synthetic algorithms for the water can enable the creation of an accurate and life like 3D printed model.
The example below is a hybrid 3D printed model of the Stone Town, Zanzibar featuring the Old Fort and the House of Wonders. It was been created in recognition of Her Excellency Dr Rawya Saud Al-Busaidi’s visit to Imperial College Advanced Hackspace and Sultanate of Oman’s support for heritage conservation in Zanzibar.
This simple model is the result of a variety of technologies already having a transformation impact on the World; from drone-based imaging, photogrammetry, 3D printing and mathematical modelling using artificial intelligence to create natural and synthetic forms. More importantly it illustrates the spirit of collaboration and creativity in Imperial College’s Advanced Hackspace (ICAH). The model highlights how the tools of the future are being applied to bring celebrate the past and open up a new era in heritage conservation, advocacy, education and cultural diplomacy.
Augmenting Reality – towards a mixed reality exhibit
The 3D model can also be used as a portal to additional information or perspectives on the site. This is illustrated by Inition’s mixed reality exhibit for the architects Zaha Hadid, to demonstrate a design for the Eli & Edythe Broad Art Museum in Michigan.
A 3D print scale model was created. Several layers were then developed which, when viewed via an iPad, overlaid the physical model with graphics boosting its value for architectural collaboration. These included internal systems, outside environment, thermal wind flow and geographical location.
This example illustrates how the transformational augmented models might be for curating exhibitions, aiding interpretation, in education and public outreach.