This blog post will serve as the first in a series of entries dissecting various elements of visual representation in the field of Digital Heritage. Before approaching the theme of this post, photorealism, I would like to briefly take a wider look at Digital Heritage itself with the view of putting photorealism in the field into context.
The use of ‘Digital’ as a prefix brings a malleability to familiar concepts and breathes life into older ones. It would appear that this field is open to various areas of debate which we explored in recent Digital Heritage classes; are Digital Heritage methods only there to serve Cultural Heritage in general or is Digital Heritage its own field? Is it the goal of its practitioners to combine newer and older methods in such a way that there is a symbiosis between itself and older methods, one which would potentially enhance the field of Cultural Heritage as a whole? As with any scholarly field, the implementation of technological methods within existing academic frameworks must surely help to alleviate a stagnation of ideas in the future, ensuring a continuing progression. When we use a phrase such as ‘Digital Heritage’, we conjure up images of a field that is heightened in some way; cutting-edge and open to innovation. If the field of cultural heritage is somehow transformed under the veil of the digital, are other existing concepts, methodologies, and tools transformed also?
Defining Photorealism: Perception, Interpretation, and Representation
The way in which we interact with the world around us is a constant combination of perception and interpretation. This differs from person to person, from culture to culture, and from school of thought to school of thought. ‘Photorealism’, in general, can be defined as follows:
“…a genre of art that encompasses painting, drawing and other graphic media, in which an artist studies a photograph and then attempts to reproduce the image as realistically as possible in another medium.”
This definition serves the general idea of process of perception, interpretation, and representation; the artist perceives its subject, they interpret its subject’s characteristics and qualities, and they then give us a representation which is supposedly as photographically close to the subject matter as possible. Accuracy is the key here. Within Digital Heritage, this concept applies on a technical level that transcends the traditional definition of photorealism, while essentially carrying out the same principle. If, say, an archaeologist is tasked with recording an object for preservation, they of course will want to produce a digital and/or physical model that is as close to the original as possible, in case of future damage to the original. In this case, there is a definite call, or need, for photo-realism as we would judge a recording against the original almost as a control as well as a recording. Hafizur Rahaman points out in Virtual Heritage: Exploring Photorealism that the development and refining of photorealism could have definite benefits in creating completely realistic representations of world heritage sites in the form of buildings or monuments. However, he goes on to point out that Maria Rossou believes that
‘…present VH projects consider ‘photo-realism’ as one of the most important measure of successfulness in representation of a virtual reconstructed site. Moreover, the affection of technology often luring us to be ‘blind’ towards an amorphous nature of history, while provokes to demonstrate the technical artistry and power of new technology’
What is presented here is the idea that trying to authentically replicate some form of physical history is to lose a sense of the history of the object itself. It is certainly not a bad things to reproduce certain objects photo-realistically for recording purposes or comparison, although conversely, are photo-realistic reconstructions of what a site or an object MAY have looked like as useful? Perhaps photorealism can better be applied within the realm of exact replication of damaged artifacts or sites as opposed to hypothetical representations, which would perhaps be better represented by non-photorealistic rendering. If the idea of cultural heritage itself is constantly evolving, do digital representations become a part of an object or site’s heritage themselves? If this is the case, then certainly photorealistic models would be beneficial in charting the evolution of digital preservation itself. Photorealistic models are therefore, within a certain context, an ‘artist’s’ representation of a particular subject matter at a specific point in time.
Immersion and Constant Change
As is the case with any form of interactive digital media, a user’s interest is ensured by an immersive experience. A feeling of being lost within that format, of ‘being there’. This is evidenced in examples such as computer games, applications on smart-phones and tablets, animations, amongst a host of others. Photorealistic representations, while offering some level of base visual interactivity to a user, are normally eschewed in favour of non-photorealistic depictions capable of greater user-interaction. However, there are some examples in which photogrammetry methodologies are used to great effect, such as Google Maps’ Street View function, or the Streetmuseum Londinium app, which provides a mix of augmented reality methods and photorealistic models of artifacts from the Roman Period in London.
Several factors usually seem to decide on the successful creation of a photo-realistic 3D model, chief among these is the quality of hardware and software available to a user. As technology advances, so to does the quality of photo-realistic models in Digital Heritage. The gradient at which improvements in techniques such as photogrammetry change and improve demonstrates a constant metamorphosis with regard to hardware and software constraints. For example; in their 2003 article Photorealism and Non-Photorealism in Virtual Heritage, Maria Rossou and George Drettakis explain how, at that time, most photorealistic models lacked the benefit of much interactivity due to “technological and methodological constraints”. Creating these models was laborious and time consuming. The fact that somebody today can create a photorealistic 3D model using a relatively low-end camera (a smartphone in some cases) and free software from the internet, such as Agisoft Photoscan or any number of similar products, would serve the idea that much of toil of the past has been left there.
In summary, this post asserts that the aesthetic of photo-realism allows us to create tangible reproductions from the real world which can have great benefits in terms of education, digital preservation, and elements of augmented reality. On the other hand, a user’s experience may be heightened or lessened by a lack of interactivity in some photo-realistic renderings. To conclude, as with most methodologies there is a time and a place for the employment of photorealism in Digital Heritage. It is purely up to the archaeologist or creator to decide whether or not this style of representation suits their user-base.
Drettkis, George, Roussou, Maria, Photorealism and Non-Photorealism in Virtual Heritage Representation, First Eurographics Workshop on Graphics and Cultural Heritage (2003), 2003, Brighton, United Kingdom. Web, accessed 10/10/15
Gutierrez, Diego et al. Virtual heritage, immersive environments and photorealism. Web, accessed 10/10/15.
Rahaman, Hazifur, Tan, Beng-Kiang, Virtual Heritage: Reality and Criticism, (January 2009), Web, accessed on 10/10/15
Rahaman, Hazifur et al. Virtual Heritage: Exploring Photorealism, (2012), Web, accessed 10/10/15
Roussou, Maria, The Components of Engagement in Virtual Heritage Environments, Web, accessed 12/10/15