Recall a grand reconstruction of an ancient place you have seen on television, in museums or in the classroom. Did you think about how that reconstruction was made? Now imagine a tool to create that reconstruction. Such a tool offers the means to materialize a vision of ancient places, represent that vision to colleagues, promote discussion of debated aspects, and present an engaging vision of the past to the public. This tool is virtual architectural reconstruction (VARch).
Figure 1: Structure A-11, Plaza A-III, Xunantunich, Belize Photo Courtesy Leah McCurdy
VARch is part of a larger category of archaeological investigatory techniques known as virtual archaeology. Generally, virtual archaeology involves digital creation tools to represent and analyze different types of archaeological datasets in a variety of ways. For instance, Geographical Information Systems (GIS) is another branch of virtual archaeology employed to represent spatial data. Virtual reconstruction is a broad term denoting activities inside and outside of archaeology to simulate and build upon reality in a virtual world. In archaeology, this typically involves the creation of virtual facsimiles or recreations of artifacts, buildings, or entire landscapes. Architecture and the built environment is the focus of this commentary.
As a research tool, VARch is a particularly visual way to analyze data, interpret evidence and support hypotheses. Most archaeologically investigated buildings do not survive in their entirety. Thus, reconstruction entails both realistic replication and addition based on informed interpretation. VARch involves the visualization of empirical data collected via direct survey of surviving building features, analysis of that data for spatial, aesthetic, and typological aspects, and development of interpretative reconstructions of non-surviving portions based on various types of evidence. Essentially, VARch is analogous to argument-based scholarship in written formats. One builds an argument (or interpretation) based on evidence collected for the specific purpose with reference to previous research. The beauty of VARch is that it allows investigators to think about a building as a designer would and in this way attempt to reconstruct a building as it was originally conceived. VARch as an investigatory technique requires an intimate knowledge of the building subject as an architectural design, constructed monument, and experienced space. With each of these perspectives, VARch becomes an integrative way to understand the ancient built environment from all its angles.
VARch in Action
As an aspect of my research in the Maya region, I developed a VARch of the royal court (Plaza A-III) surviving at the archaeological site of Xunantunich, Belize (Video 1).
Video 1: VARch of Xunantunich Royal Court
This architectural complex holds much significance for the history of Xunantunich’s rulers’ political claims and probable demise. With a focus on the architectural history of the royal court, I used VARch to develop four alternative hypotheses about the changes made over time at the palace (Structure A-11 [Figure 1]) in particular. In 3D virtual space, I faithfully recreated virtual versions of the surviving portions of the royal court and added informed reconstructions based on archaeological data recovered at the structure, analogies to other buildings at Xunantunich, and general knowledge of lowland Maya architectural style and construction. Once viewed as a virtually reinstated architectural complex and analyzed through structural, aesthetic, and functional lenses, I proposed a revised architectural history of the palace. Through VARch, I was able to demonstrate that a completely unknown original building phase must have existed and various layout changes intended to restrict access to interior living spaces began from a less restricted original architectural design (Video 2). These findings reinforced Jason Yaeger’s interpretations of political instability during the final phases of extensive occupation in Xunantunich’s monumental city center.
Video 2: VARch of Xunantunich Palace showing newly discovered, original construction phase and transition to the final construction phase.
Recently, I shifted my focus to El Castillo, the architectural centerpiece of Xunantunich (Figure 2). I am currently developing a VARch of El Castillo aimed at investigating questions of architectural design and construction carried out by Xunantunich’s ancient builders. VARch is the perfect tool to visually analyze El Castillo through its long construction history and investigate hypotheses related to its architectural change.
Figure 2: El Castillo, Xunantunich, Belize Photo courtesy Leah McCurdy
VARch Methodology
The foundation of any VARch is 3D data collected as virtual coordinates representing the relative locations of building features. The most common and efficient survey method for collecting 3D virtual coordinates is electronic distance measurement (EDM) using a total station theodolite or laser scanner. 3D survey of architecture is more detailed and smaller in scale as compared to large landscape surveys often undertaken with EDM. Often, the dataset acquired during 3D architectural survey is dependent on the size and design features of a building. Adequate recording of EDM locations and coordinate sequences during survey is essential to ensure that 3D data will be understood once visualized in virtual space.
The data collection phase culminates with the initial visualization of 3D coordinate data. This process can be undertaken in many different software packages such as ArcGIS (for landscape oriented surveys), GoogleEarth, or Computer-aided Drafting (CAD) programs. For VARch, CAD software offers 3D tools to recreate surfaces and design features with much more precision than mapping software packages. Coordinates can be easily imported into various CAD programs and immediately visualized in 3D virtual space (see Video 3 beginning). Coordinate data is plotted relative to a reference grid and can be manipulated for directionality, scale, and reconstruction.
Video 3: Demonstration of recreating walls of Structure A-32 (El Castillo, Xunantunich, Belize) from EDM 3D data. This video was created using screen capture software. The video speed is accelerated.
As an initial reconstructive step in my methodology, I use CAD virtual drafting tools to ‘connect the dots’ and create a virtual representation of the building’s current state (Video 3). This initial model is a baseline for architectural analysis and interpretive reconstruction. Layer functionality in CAD programs (similar to that in GIS software) allows the separation of different phases of VARch. Typically, I distinguish phases based on the degree of separation from the survey data. For example, the initial model recreating surviving building remains is separated from (while linked to) the reconstruction of hypothesized roofs or possible decoration. As reconstruction progresses, phases become increasingly dependent on previous reconstructive decisions, thus linkages between phases are crucial traces of the path from direct evidence to informed hypotheses of form and appearance. Preliminary line representations of a VARch are transformed into 3D solids to give mass to a virtual building (Video 4). These 3D solids can be fleshed out for more aesthetically pleasing representations.
Video 4: Demonstration of “extruding” walls into 3D in AutoCAD software based on wall recreation (Structure A-32, El Castillo, Xunantunich, Belize). This video was created using screen capture software. The video speed is accelerated.
To fully reconstruct an ancient place, a VARch should incorporate aesthetic properties that are as accurately representative of the architectural context as possible. Visualizing architectural materials and their surface qualities within a VARch serves as a record of archaeologically recovered data and offers an important touch of realism to a virtual representation (Video 5).
Video 5: Demonstration of adding architectural materials (plaster, wood, etc.) to 3D objects and environmental qualities to scene (light, shadow, etc.) in Blender software. This video was created using screen capture software. The video speed is accelerated.
Additionally, simulating environmental qualities provides appropriate context and assists the viewer in recognizing the reality that the creator endeavours to present (see Video 5). Environmental context also offers an experiential setting for exploring a reconstruction as an ancient person may have. Light, shadows, time of day, color, and/or material can influence experiences of an architectural space. VARch allows people to experience past built environments with virtually realistic changes in environmental qualities. Various 3D graphics software packages offer relatively easy transitions from CAD programs. There are extensive options available to simulate architectural materials or to apply specific photographs of materials to reconstructed surfaces. Environmental qualities can also be simulated through estimation or in some cases can be precisely realistic through geographically referenced data.
If a VARch creator is interested in developing a reconstruction for presentation or publication, there are some important avenues to consider. First, digital images of a VARch from various angles can suffice to illustrate an architectural complex (see Video 5 for image creation). Videos can also be complied through digital animation of virtual scenes using the same types of 3D graphics software as discussed above (Video 6).
Video 6: Demonstration of “key-framing” an animated video of Structure A-32 (El Castillo, Xunantunich, Belize). This video was created using screen capture software. The video speed is accelerated.
Animated “fly-through” videos are the most recognizable sort of VARch presentation (Video 7).
Video 7: Example of animated fly-through VARch highlighting Structure A-32 (El Castillo, Xunantunich, Belize).
Audiences of VARch images or videos often lament the lack of interactivity. In response, VARch creators can implement their reconstructed spaces in video game engines to allow real-time movement within the virtual architectural space as if the visitor is engaged in a video game scene (without gun fights and magical powers of course). This sort of development in VARch enhances user experience and broadens the potential uses for archaeologically responsible reconstructions of ancient spaces.
VARch Improvements and Involvement
Even great tools are not perfect. VARch entails some issues that should be recognized and addressed by current and future “VARchies.” The visual products that result from different VARchs of the same building (created by different people) can be vastly different. While based on empirical data specific to a particular building, VARch is a multi-faceted methodology with many subjective elements. VARchs can differ based on the hypotheses implemented in the virtually reconstructed building, the style of virtual features, and the degree to which the reconstruction reflects a realistic setting or schematic drawing. Standards of creation, implementation, as well as storage are much needed to ensure the veracity and viability of virtual archaeological techniques in scholarly research. Principally in the UK and Europe, some scholars focus on discussions of what virtual archaeology is, how it should be used, and why. Through such self-critique and collaboration, VARch can become a more widely used and cited archaeological technique.
As viewers are immersed in the virtual experience of flying through an ancient architectural masterpiece, the roots of that recreation can be obscured. Some prettily packaged reconstructions may not be adequately supported by archaeological evidence or informed interpretation. While it is difficult to police, the virtual archaeology community promotes responsible reconstruction practices. For VARch in particular, it is paramount that creators document their reconstruction hypotheses. Towards this end, I create a transparency record of process data (paradata) as an aspect of my work. VARch paradata should include documentation of the sequence of reconstruction, archaeological and/or documentary evidence, linkages to surviving remains, and alternative hypotheses. With this information, viewers can understand the creator’s reasoning and argumentation for the reconstruction. The most transparent VARchs visually incorporate paradata into the reconstruction presentation and thus highlight their data and supported argument.
VARch will also improve as more scholars become interested in the research possibilities and experiment with the methodology. While it may seem technically involved, only basic computing knowledge is needed to learn CAD and 3D graphics software. Online resources abound for newcomers to virtual techniques. If you are looking for a less technically demanding introduction to VARch, many animations and even game experiences are available online. Becoming part of the VARch audience will improve the visibility of this new methodology for archaeological research and not just for fancy television graphics. As improvements build and involvement increases, VARch will become a widespread research tool for reconceptualizing architectural histories and integrating architectural knowledge into archaeological interpretations.
Leah McCurdy is a PhD student in anthropology at the University of Texas at San Antonio. Her research interests are monumental architectural production in complex societies, virtual architectural reconstruction, and cognitive studies of design and creativity.