Part 3 – Sources and Paradata

Before going into the bulk of how to model an archaeological site and why do it, I would like to spend a moment discussing the research that should be at the basis of the model itself. The fact that 3D Reconstruction is in its infancy brings many advantages and disadvantages to the table. On the one part, it is exciting to think there is so much we do not know as it means endless applications are there just waiting to be discovered. On the other hand however, there is a distinct lack of consistent methodology between projects and while some publication are clearly founded on extensive research (Dawson et al. 2011 amongst many others), others seem to be more loosely interpreted.

324t343t

Fig.1 – The first steps in modelling, based on a plan of the site to scale.

This is one of the reasons behind ‘paradata’, a term that has recently been applied to the field. To understand paradata we need to first discuss metadata. Especially in computer science, many authors have lamented the inability to replicate experiments involving code (Hafer and Kirkpatrick 2009; Boon 2009; Ducke 2012; Hayashi 2012). In the words of Marwick:

“This ability to reproduce the results of other researchers is a core tenet of scientific method, and when reproductions are successful, our field advances (Marwick 2016, pp.1).”

and

“A study is reproducible if there is a specific set of computational functions/analyses (usually specified in terms of code) that exactly reproduce all of the numbers and data visualizations in a published paper from raw data (Marwick 2016, pp.4).”

Essentially the debate is that publishing results is not enough, but that instead we should include additional information, such as settings used in a program or the raw code. This collection of information is referred to as ‘metadata’. Some authors on the other hand have taken it a step forward, arguing that we should include descriptions of the process, a discussion of the choices made and the probabilities (Denard 2009; Beacham 2011, D’Andrea and Fernie 2013). This ‘paradata’ is best described in the London Charter, which is the first attempt to creating a methodology in 3D Reconstruction:

“Documentation of the evaluative, analytical, deductive, interpretative and creative decisions made in the course of computer-based visualisation should be disseminated in such a way that the relationship between research sources, implicit knowledge, explicit reasoning, and visualisation-based outcomes can be understood (Denard 2009, pp.8-9).”

Given that a major critique in 3D Reconstruction is accuracy (Miller and Richards 1995; Richards 1998; Devlin et al. 2003; Johnson et al. 2009), paradata is our way to defend ourselves. While it is impossible to create the perfect model, by demonstrating the process behind the reconstruction allows a user to understand the interpretation given and draw their own conclusions.

Roman Villa 4

Fig.2 – A highly speculative Roman Villa. Without knowledge of the process it is impossible to know how accurate each element is.

One of the elements we have mentioned previously are sources. While the process itself has to be methodical in order to gain accurate results, the sources provide the wireframe upon which the interpretation can take place. It therefore essential that the sources are well researched and well documented. For this purpose I like the classification proposed by Dell’Unto et al. (2011), which sees different categories based on accuracy:

  • Reconstruction by Objectivity: sources based on in situ elements, like plans, 3D scans, archives.
  • Reconstruction by Testimony: illustrations, literary sources, notes.
  • Reconstruction by Deduction: elements that can be deduced from in situ remains, but that are not actually there.
  • Reconstruction by Comparison: based on other sites, this is actually quite an important one as a lot of features carry on between remains of the same regions.
  • Reconstruction by Analogy of Styles: especially for decoration, looking at other stylistic elements that have been preserved can help make the whole model look more realistic.
  • Reconstruction by Hypothesis: an essential part of reconstruction, but the most inaccurate.

Of course, the more we go down this ladder, the more inaccurate the sources are. Yet it is by combining all the different sources that we get the finished model. Paradata can help with determining which sources were used for each part of the model, and therefore provide information of the model as a whole.

house6

Fig 3 = Partly completed model of a Greek house, based on plan, excavation reports and site comparison.

In conclusion, there are many sources that can be used when constructing a model and although some are more precise than others, all of them contribute to the final result. If they are applied methodologically and the process is recorded, we can provide an accurate and reliable reconstruction.

Over the next posts I will start looking at SketchUp for modelling, although the ideas will carry over to other software such as 3Ds Max.

REFERENCES:

Beacham, R. C. (2011). Concerning the Paradox of Paradata. Or, “I don’t want realism; I want magic!”. Virtual Archaeology Review Vol.2 No.4 pp.49-52.

Boon, P., Van Der Maaten, L., Paijmans, H., Postma, E. and Lange, G. (2009). Digital Support for Archaeology. Interdisciplinary Science Reviews 34:2-3 pp.189-205.

D’Andrea, A. and Fernie, K. (2013). CARARE 2.0: a metadata schema for 3D Cultural Objects. Digital Heritage International Congress Vol.2 pp.137-143.

Dawson, P., Levy, R. and Lyons, N. (2011). “Breaking the fourth wall”: 3D virtual worlds as tools for knowledge repatriation in archaeology. Journal of Social Archaeology 11(3) pp.387-402.

Dell’Unto, N., Leander, A. M., Ferdani, D., Dellepiane, M., Callieri, M., Lindgren, S. (2013). Digital reconstruction and visualisation in archaeology: case-study drawn from the work of the Swedish Pompeii Project. Digital Heritage International Congress pp.621-628.

Denard, H. (2009). The London Charter: for the computer-based visualisation of cultural heritage.

Devlin, K., Chalmers, A. and Brown, D. (2003). Predictive lighting and perception in archaeological representation. UNESCO World Heritage in the Digital Age.

Ducke, B. (2012). Natives of a connected world: free and open source software in archaeology. World Archaeology 44:4 pp.571-579.

Hafer, L. and Kirkpatrick, A. E. (2009). Assessing Open Source Software as a Scholarly Contribution. Communication of the ACM Vol.52 No.12 pp.126-129.

Hayashi, T. (2012). Source Code Publishing on World Wide Web. International Conference on Advanced Information Networking and Applications Workshops pp.35-40.

Johnson, D. S. (2009). Testing Geometric Authenticity: Standards, Methods, and Criteria for Evaluating the Accuracy and Completeness of Archaeometric Computer Reconstructions. Visual Resources 25:4 pp.333-344.

Marwick, B. (2016). Computational Reproducibility in Archaeological Research: Basic Principles and a Case Study of Their Implementation. Journal of Archaeological Method and Theory pp.1-27.

Miller, P. and Richards, J. (1995). The Good, the Bad, and the Downright Misleading: Archaeological Adoption of Computer Visualisation. In: Huggett, J. and Ryan, N. Computer Applications and Quantitative Methods in Archaeology. Oxford: Tempus Reparatum pp.19-22.

Richards, J. D. (1998). Recent Trends in Computer Applications in Archaeology. Journal of Archaeological Research Vol.6 No.4 pp.331-382.

Part 2 – 3D Reconstruction Literature

In this section I would like to go through some projects I have been reading about that I think are very useful for understanding 3D Reconstruction in Archaeology. Before delving into the practicalities of the technology it is important to assess where the field is at right now.

champion

An image from Champion et al. (2012) showing the reconstructed city of Palenque.

If you look through the literature, 3D Reconstruction is often scarcely documented and results are limited. The three major critique points I have encountered are to do with accuracy, lack of human element and on use. Here is a brief overview:

  • Accuracy: studies lack background information on how the model was achieved, and create the false idea that the reconstruction is absolutely certain, while often it is simply one of many interpretations.
  • Lack of human element: based on Thomas (2004a; 2004b) and Tilley (2004), 3D Reconstruction is seen as a purely visual subject, alienated from human experience.
  • Use: 3D modelling is used simply to present sites, and are seen as add-ons. In reality, they provide great scope for interpretation.

The first paper I would like to mention is “Digital reconstruction and visualisation in archaeology” by Dell’Unto et al. (2012). On the subject of accuracy in 3D Reconstruction, Dell’Unto et al. propose the use of a series of levels of reconstruction: by identifying and recording the sources for each portion of the model, it is possible to assess the relative accuracy of each part. The first level of reconstruction is based on in situ elements, which are nearly certain, while the last level is dedicated to purely hypothetical reconstructions. This is a great approach as it means the modeller is accountable for the model, but at the same time they have the freedom to experiment as it is clear from the recording what they have done.

dell'unto

Levels of reconstruction by Dell’Unto et al. (2012).

On the topic of human experience, I can mention a few papers that implicitly refute the ideas proposed by Tilley and Thomas. While 3D modelling is indeed an exceptionally visual subject, it is not simply about looking at images. An entire current of thought deals with ‘presence’, the feeling of belonging a person gets when exploring a 3D environment. It seems that people get involved with the models to the point they ‘experience’ them, as if they were present on site. So while Tilley and Thomas refuse Visualisation as they prefer to explore the site in first person, I would argue that you can do that with 3D Reconstruction. An author I have come across which deals with ‘presence’ is Ch’ng (2009; Ch’ng and Stone 2006; Ch’ng et al. 2011), although I think the forerunner of this field is Chalmers (2002; Chalmers and DeBattista 2009; Devlin and Chalmers 2001; Devlin et al. 2003; Gutierrez et al. 2006). He has made exceptional steps in recreating archaeological sites with near perfect realism, in order to increase the sense of ‘presence’ people experience. His work on illumination is unmatched, and his articles are well worth a read.

chalmers and debattista

Different lighting effects as studied by Chalmers and DeBattista (2009).

Additionally the work of Dawson and Levy (2006; Dawson et al. 2007, 2011, 2013) are an exceptional testimony of how people respond to 3D environments. They recreated a Thule hut and then invited some members to explore them, recording their reactions and showing their emotional attachment.

Dawson and Levy are also prime examples of 3D Reconstruction being used for interpretation, as their analysis of hut building showed that there was significant reuse of bone structures. Many others have explored the utility of this type of technology, so it is hard to pinpoint individual papers of significance. Champion et al. (2012) use gaming software to educate users on the archaeology of the Palenque city. This is by far one of the best studies I have encountered, and I believe they are the forerunners of ‘serious games’ for archaeology.

champion 2

Another view of the ‘serious game’ by Champion et al. (2012).

Similarly the work of Forte et al. (2012) shows much promise in the same area. Finally, the work of Murgatroyd et al.(2011) is not strictly related to reconstruction, but the simulations they have run on Byzantine army movement is very important for understanding the reach of scripting, which can be combined to 3D reconstruction.

I hope this has provided you with an overlook of all the potential applications of 3D software. Over the next couple of weeks I aim to outline the reconstruction process, in order to open up the path to scripting.

 

REFERENCES:

Ch’ng, E. and Stone, R. J. (2006). 3D Archaeological Reconstruction and Visualisation: An Artificial Life Model for Determining Vegetation Dispersal Patterns in Ancient Landscapes. Proceedings of the International Conference on Computer Graphics, Imaging and Visualisation.

Ch’ng, E. (2009). Experimental archaeology: is virtual time travel possible? Journal of Cultural Heritage 10 pp.458-470.

Ch’ng, E., Chapman, H., Gaffney, V., Murgatrayd, P.. Gaffney, C. and Neubauer, W. (2011). From sites to landscapes: how computer technology is shaping archaeological practice. IEEE Computer Society 11 pp.40-46.

Chalmers, A. (2002). Very realistic graphics for visualising archaeological site reconstruction. Proceedings of the 18th Spring Conference on Computer Graphics pp. 7-12.

Chalmers, A. and DeBattista, K. (2009). Level of realism for serious games. 2009 Conference in Games and Virtual Worlds for Serious Applications pp.225-232.

Champion, E., Bishop, I. and Dave, B. (2012). The Palenque project: evaluating interaction in an online virtual archaeology site. Virtual Reality 16 pp.121-139.

Dawson, P., Levy, R., Gardner, D. and Walls M. (2007). Simulating the Behaviour of Light inside Arctic Dwellings: Implications for Assessing the Role of Vision in Task Performance. World Archaeology Vol.39 No.1 pp.17-35.

Dawson, P., Levy, R. and Lyons, N. (2011). “Breaking the fourth wall”: 3D virtual worlds as tools for knowledge repatriation in archaeology. Journal of Social Archaeology 11(3) pp.387-402.

Dawson, T., Vermehren, A., Miller, A., Oliver, I. and Kennedy, S. (2013). Digitally enhanced community rescue archaeology. Proceedings of First International Congress on Digital Heritage pp.29-36.

Devlin, K. and Chalmers, A. (2001). Realistic visualisation of the Pompeii frescoes. Proceedings of the 1st International Conference on Computer Graphics, Virtual Reality and Visualisation pp.43-48.

Devlin, K., Chalmers, A. and Brown, D. (2003). Predictive lighting and perception in archaeological representation. UNESCO World Heritage in the Digital Age.

Dell’Unto, N., Leander, A. M., Ferdani, D., Dellepiane, M., Callieri, M., Lindgren, S. (2013). Digital reconstruction and visualisation in archaeology: case-study drawn from the work of the Swedish Pompeii Project. Digital Heritage International Congress pp.621-628.

Forte, M., Lercari, N., Onsurez, L., Issavi, J. and Prather, E. (2012). The Fort Ross Virtual Warehouse Project: A Serious Game for Research and Education. 18th International Conference on Virtual Systems and Multimedia pp.315-322.

Gutierrez, D., Sundstedt, V., Gomez, F. and Chalmers, A. (2006). Dust and light: predictive virtual archaeology. Journal of Cultural Heritage 8 pp.209-214.

Levy, R. and Dawson, P. (2006). Reconstructing a Thule whalebone house using 3D imaging. IEEE MultiMedia. Vol.13 No.2 pp.78-83.

Murgatroyd, P., Crenen, B., Theodoropoulos, G., Gaffney, V. and Haldon, J. (2011). Modelling medieval military logistics: an agent-based simulation of a Byzantine army on the march. Computational and Mathematical Organization Theory Vol.18 No.4 pp.488-506.

Thomas, J. (2004). Archaeology and Modernity. London: Routledge.

Thomas, J. (2004). The Great Dark Book: Archaeology, Experience, and Interpretation. In: Earle, T. and Pebbles, C. S. A Companion to Archaeology. Oxford: Blackwell Publishing pp.21-36.

Tilley, C. (2004). The materiality of stone: exploration in landscape phenomenology. Oxford: Berg.

PART 1 – Visualisation

ggantija

“Visualisation” is a term that is used quite consistently in recent archaeological publications. It refers to the reconstruction of archaeological evidence through the use of computer software, although it originates in the practise of recording the site using 2D drawings which has been around for a few centuries. Although the meaning of the word and what it entails fluctuates somewhat, I’ve come to identify three types of technologies that fall within this category:

  • Photogrammetry
  • Laser Scanning
  • 3D Reconstruction

Photogrammetry is also referred to as Structure From Motion, and differs from the other methods as the 3D models are based on photographs (Pedersini et al. 2000). Similarly to laser scanning, the result is a high density point cloud, with photorealistic textures.

Laser scanning is a powerful tool widely used in large scale recording. It uses laser measurements to calculate the position of points in a site, and like Photogrammetry it produces a textured mesh, although generally laser scanning models are much more dense and therefore more accurate.

3D reconstruction is the method we will be primarily dealing with. It is less accurate than Photogrammetry and laser scanning, and the results are less realistic. It does however possess some distinct advantages. Reconstructed models are easily manipulated, and often represent elements of a site that have been lost (Fig.1). They can also be combined with gaming software to create interactive environments (I could cite many authors here, but just as a taster I would recommend reading Champion et al. 2012).

image 1

Fig.1 = 3D Reconstruction of the site of Ggantija, Gozo.

The three methods have very different aims, and as such it is important to know what you want to achieve before applying them:

  • For small and medium scale recording Photogrammetry is excellent (Scopigno 2012). It is very cheap and fast, and possesses the accuracy and visual effects that are necessary for recording and presenting. It is ideal for cataloguing finds or small scale excavations, although it can be used for larger features if necessary (see the current Must Farm excavation models by Donald Horne for more details: https://sketchfab.com/mustfarm). The fact it possesses lower points than laser scanning makes it easy to manage, and it requires little training.
  • For detailed models and large sites Laser Scanning is the tool of choice. More expensive and computationally challenging than Photogrammetry, laser scanning creates precise models that are perfect for recording, presenting and some interpreting. A great example is the work of John Meneele (https://www.facebook.com/1manscan/) who has been analysing stone decay be comparing models taken in different years. I personally have little experience with laser scanning, but the results I have seen have shown a lot of promise.
  • 3D Reconstruction is mainly for presentation and interpretation. Although some arguments have been put forward on using 3D reconstructions for metadata recording, this is not where the technology shines (Reilly 1990; Barreau et al. 2013). 3D reconstructions can show a site “as it was” rather than “as it is”, leading to a more vivid understanding of archaeological contexts (Miller and Richards 1995; Lewin and Gross 1996). For the general public it is perfect, and it can be made highly interactive in order to further increase user comprehension of the archaeology. As for interpretation, the use of scripting allows a number of tools to be created in order to answer archaeological questions. One of the projects I have been working on was looking at analysing solar alignment at a Maltese site, and through a custom-written script I concluded the site is illuminated on the winter solstice (Fig.2). While Photogrammetry and Laser scanning shine with precision and photorealism, 3D Reconstruction truly dominates in presentation and interpretation.

 

overall image

Fig.2 – Overview of the script interface.

It is important however to mention how these methodologies are not mutually exclusive. Little work has been done in combining different techniques, but the results show much promise. A previous article on this blog discussed virtual museums, and the combination of a 3D reconstructed environment, with Photogrammetric models within.

In conclusion, there is a lot of technology put there, and although research is slowly unveiling the advantages of each there is much to be discovered still. With 3D Reconstruction we are barely scratching the surface, and only in the last 10 years we have had custom written scripts for archaeology. It may take a while, but once we uncover what is possible, archaeology will really reap the results.

 

In the next post I will be looking at previous work in 3D reconstruction, with a few examples of significant projects that have helped shape the methodology.

 

REFERENCES:

Barreau, J., Gaugne, R., Bernard, Y., Le Cloiree, G. and Gouranton, V. (2013). The West Digital Conservatory of Archaeological Heritage Project. Digital Heritage International Congress. Vol.1 pp.547-554.

Champion, E., Bishop, I. and Dave, B. (2012). The Palenque project: evaluating interaction in an online virtual archaeology site. Virtual Reality 16 pp.121-139.

Lewin, J. S. and Gross, M. D. (1996). Resolving Archaeological Site Data With 3D Computer Modeling: The Case of Ceren. Acadia pp. 255-266.

Miller, P. and Richards, J. (1995). The Good, the Bad, and the Downright Misleading: Archaeological Adoption of Computer Visualisation. In: Huggett, J. and Ryan, N. Computer Applications and Quantitative Methods in Archaeology. Oxford: Tempus Reparatum pp.19-22.

Pedersini, F., Sarti, A. and Tubaro, S. (2000). Automatic monitoring and 3d reconstruction applied to cultural heritage. Journal of Cultural Heritage 1 pp.301-313.

Reilly, P. (1990). Towards a virtual archaeology. In: Lockyear, K. and Rahtz, S. Computer Applications in Archaeology pp.133-139.

Scopigno, R. (2012). Sampled 3D models for Cultural Heritage: which uses beyond visualisation? Virtual Archaeology Review Vol.3 No.5 pp.109-115.

A Theoretical Approach to Photorealistic 3D Video: the Future of Film and Gaming?

Generally I am not a big fan of theoretical issues, especially when it comes to something as practical and visual as 3D modelling. This however is something I cannot really experiment with practically (or within an acceptable time frame), so for now it has to remain in the grounds of theory. It is also not strictly archaeological, although I’m sure some applications must come from it.

What I mean with Photorealistic 3D Video is taking the still photogrammetric models you’ve seen before and applying movement to it. This can be done by using either stop motion or a combination of cameras to acquire the original footage, then modelling individual frames and putting the frames in a sequence.

Image

The acquisition of footage depends on what you are trying to achieve. If the object is still itself and it’s going to be moved frame by frame (like traditional stop motion animation) then a single camera is required. Instead of taking a single photo of the scene, like in standard animation, a series of images would be taken to make a Photogrammetric model, as explained previously on this blog. If instead the object is already in motion, as for example an individual acting out a scene, the trick is to use a large number of video-cameras that surround the object, using the same positions described before (a good example of this can be seen here http://www.webpronews.com/get-a-3d-print-of-yourself-in-texas-2013-08). With all the cameras then each frame is isolated as if photographs of the scene were taken at the same time from all angles. With either method, the results should be a large number of frames (24 for second or more depending on format), each of which is made up by 20 to 30 images.

The second step is the creation of the models. This can be done using 123D Catch or any other Photogrammetric software. Each series of images constituting a frame are hence transformed into a single rotatable 3D model.

Then all the frame models are run through other software, at present I am leaning towards gaming software, but video editing software or animation software may be more suitable, so possible options are Unity 3D, Maya or After Effects. Some alignment will have to take place, but by superimposing the models on top of each other and making it so that a single one is visible at a time should create an animation effect, again like stop motion. This is the part I am most unsure about, due to it being quite a demanding task, which may be far too complex for computers at this time. Still, in the future it should be more than possible.

Image

At this stage the result is a series of still models that run through giving the illusion of movement. This can then be combined with technology that is now appearing on the market. In particular it could be used with the Oculus Rift that is soon going to revolutionise how 3D gaming works. By tracking the position of the user, it would be possible to not only see the Photorealistic Video, but also move around it as if it were real. By combining more than one model an entire scene could be created, meaning 3D films in which the user is actually present within the film can become a possibility, as well as uber-realistic videogames.

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Virtual Museums: Combining 3D Modelling, Photogrammetry and Gaming Software

I wrote the post below yesterday night, but since it was written I’ve managed to create at least a part of what is described in the text, which is shown in the video above. Hence keep in mind that the rest of the post may be slightly different from what is in the video.

One of the more popular posts I’ve published seems to be the one about public engagement at Caerau, South Wales, in which I created an online gallery with the clay “Celtic” heads school children made. The main concept that I was analysing in the text was the idea that we could create digital galleries in which to display artefacts,

When I wrote the word gallery I imagined the computer definition of gallery, as in a collection of images (or in this case models) within a single folder. However I have since found this: http://3dstellwerk.com/frontend/index.php?uid=8&gid=18&owner=Galerie+Queen+Anne&title=1965%2C85%C2%B0C

This is an example of what the website http://3dstellwerk.com offers, an opportunity for artists the create a virtual space in which to display their work. It allows users to go “walk” through the gallery and view the 2d artwork as if it were an actual exhibition. Although the navigation may require a little improvement, it is a brilliant idea to make art more accessible to people.

Virtual Museum

This idea however could easily be adapted for archaeology, using Photogrammetry, Making models of a selection of artefacts using 123D Catch, we can then place them within a virtual space created with our 3D software of choice, in order to then animate it using gaming software such as Unity 3D which would allow user interaction. A large scale project could even allow the objects to be clicked in order to display additional information, or create audio to go with each artefact. Video clips could also be incorporated within the virtual space.

Virtual Museum 2

On an even larger scale this could mean we can create online museums available to all and with specific goals in mind. As we are talking of digital copies of objects, it would be possible to group in a single virtual space a number of significant objects without having to physically remove them from their original location.

The only problem that we may encounter with this idea is file size, as each photogrammetric model is relatively small and manageable, yet if we want a decent sized virtual museum we are going to need a large portion of data. Still, even if the technology at present is not quite capable of dealing with the bulk, the rate at which it is improving will allow such ideas to be doable in the near future.

Virtual Museum 3

Basics of Coding for Archaeology: Scripts and Text

Before reading this post, please look at my previous post. Seriously, it will mean nothing to you otherwise. Yesterday I went through the basic layout of Game Maker, and explained the difference between rooms, sprites and objects, as well as basic commands using events and actions. Today we will expand this last concept and look at how we can display prewritten text on the screen. The main aim of this series of post is to give an overview of how we can use gaming software to create programs that can help archaeology.

As we saw last time we could easily write some text on the screen by using a series of action drop boxes that game maker has prepared for us, and in some cases this is an efficient and easy approach. But I’ve found that when making a more complex program you can go insane with the number of action drop boxes you would have to use. Hence I like to use Game Maker Language to tell the program exactly what want it to do.

The first step is to create a new object. We can ignore sprites (the visual component) this time as the object is not going to be visible on screen. We can then rename the object something like text_ctrl. This object will have a series of commands attached to it that it will follow at a certain point we decide, the event. In this case the event is going to be the “Draw” event, which means the action happens at all times. The “Draw” event is like the Step event I mentioned yesterday, but the former is connected with making things appear on the screen, so anything visual usually ends up in this event. If for example we are deciding how an object moves, then the step event is more appropriate, while creating a rectangle with certain dimensions is in the realm of the Draw event.

Image

Having decided when the action happens (all times) we then go to the “control” panel and choose the “execute script” action. This is where the coding happens, and where it all gets complicated yet interesting. Copy and paste the following:

{

draw_text(50,60,“Archaeology is pretty much the best thing ever.”);

//draws the text at position, creating new line when reached position

}

Save the object and then create a room in which add the object, which will appear as a blue ball with a question mark. Then run the game (green arrow) and hopefully you should get a screen that displays the message.

Image

What you are doing is running a script. You are telling the program to draw a piece of text, using what is called a function (draw_text), and you are giving it some parameters to follow. First of all, you are telling it where the text goes. The rooms are divided up by a grid, each point of which is recognisable by an x and a y. The point in the top left corner has an x of 0 and a y of 0, while all other points on the screen have an x and a y depending on where they are. The further down they are on the page, the more the y is going to increase, and the further across the point is, the higher the value of x. In this case we have told the program that we want the text to be at the point x=50 and y=60.

We then told it what we want to say, using a “string”, which you can recognise because they are within the “ ”. Within the “ “s you can write whatever you want, and use whatever symbols you want, without making any difference to the code itself. Outside them any small change can really create problems with the code.

A few more things to notice. I’ve used the brackets { and } to open and close a part of text I want to be separate from other parts of text. This means it will work as a block, and if many functions are within it they too form a block. At the moment they seem pointless, but they will become more and more important. Also, the ; closes a function, making space for another, while the ( and ) brackets are used to specify the parameters of the function. Finally the // and everything that follows is a comment, a way for me to put a note to myself to know what is going on. The program recognises the //s and ignores anything that follows on the same line.

A last piece of code is a slightly extended version of the one before:

{

draw_text_ext(50,60,”Archaeology is pretty much the best thing ever, except for making origami, because at least origami doesn’t pretend it has an edge that is nowhere near where you expect it, meaning you spend three days looking for something you thought would take you two minutes to find.”,-1,150);

//draws the text at position, creating new line when reached position

}

The function here is draw_text_ext() and it allows a few more things to take place. First of all It sets a limit to the line you are writing, in this case x=150. When the code gets to that point it automatically creates a new line underneath, at a distance specified by the -1 (which for some reason is the standard number to use). This way you can write long pieces of code without running out of the screen.

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Basics of Coding for Archaeological Programs: Game Maker Overview

Image

I am not a coder. I am especially not a gaming coder. I am however an archaeologist interested in all aspects of digital archaeology, from 3D modelling to Cad surveys, and I enjoy bending the original use of programs to fit my own needs. The best example I’ve ever seen of this is when some archaeologists used a Kinect to survey a room in 3D.

One of the most interesting programs I’ve ever used is Game Maker. It is not easy, not easy at all, and the main purpose is the creation of small .exe games. However the potential of this program is much more, as it is theoretically possible to do anything using the Game Maker Language, and I’ve seen some people make impressive 3D viewing software. What I am interested in is the ability to create programs to be used in archaeology, and up to now I’ve had success in two projects, one regarding the creation of interactive plans of sites, the other a small game to teach kids the workings of a hill fort.

Given the great potential, I thought it may be worth going through the steps for creating a program for all archaeologists who may be interested in doing so. The first thing to note is that Game Maker is similar to Dreamweaver in that it possesses tools to simplify coding, but allows some coding to be done if needed. The drop boxes used by GM are great to start off, but they get increasingly difficult to use the more complex the program gets. For this reason I use a combination of the two.

GM uses three main elements to create games: rooms, sprites and objects. Rooms are were everything happens. They are were the objects are placed and where they interact with one another. A game can have many rooms or a single room, and we decided what happens in each. Sprites are the images that we see. In the game Tetris, the various shapes can be seen because we have an image file opened as a sprite. What happens to the shapes though is decided by the objects, each of which has the sprite associated to it. The objects are where the coding happens, in which we tell the computer what we want it to do.

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So, in Space Invaders we have a single room where the entire game takes place, we have a series of objects with certain commands and represented by image files called sprites. This is the basic working of games, and with programs it is the same. In Word we could say we have a “room” which is everything we see when we open it up, a series of “objects” which are the buttons we can press, each of which is coded to do something, and which are represented by “sprites”, the icons.

The next thing to look at is how to create an object with a sprite in a room. First of all we create a new sprite, and upload the image we want to use. Then we create an object, and in the box that appears we select the sprite we want in the sprite box. Finally we create a room and place the object within the grid that appears. If we then click the green arrow in the toolbar it all opens up, and we have an empty window with the image we selected at the position we told it. Of course nothing happens because we haven’t told the object what to do.

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This is the hard part. The commands an object follows are made of two parts: the event and the action. The event tells the object when something happens. It means that if you tell the program that when you click on the object it moves left, it won’t just move left any time, but only when you click it. The action is instead what happens when the event takes place. GM allows you to choose from a large list of events and actions. The main events to remember are the create event, which means that the event happens when the room is opened, and the step event, which means the action happens at any time.

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As an example let’s set the event as left key pressed and the action as movement, clicking on the left arrow and the speed as 4 (the speed at which it will move). When we press the green arrow now the room will open up and when we click the left keyboard key the object will move left, without stopping.

I realise this is not strictly archaeological, but I’ll get to that. In the next couple of days I will explain a bit more about this and go into the coding process.

Using Gaming Software for Archaeology

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Say you have a large archaeological site with many features and much to show. Say you want your site to be accessible to everyone who has an interest in it, regardless of their knowledge of the period or of archaeology in general. How would you go about showing what you have found in the most appealing and simple way to the general public?

Of course there is not one single answer to this question, and many methods of public engagement are available to you. However I’d like to suggest a newer and more visually stimulating way of presentation, by combining archaeology with gaming software.

I personally enjoy playing around with Game Maker from time to time, a program specifically designed to create games in a simple fashion, and that can easily be adapted to create any type of program. But beware, Game Maker is not an easy program. Behind a simple-looking interface hides a complex script writing process that means you have to know at least a bit of programing to do anything good.

Given the nature of the program the possibilities are endless, and the final result depends solely on the imagination and time available. One of the projects I was working on was to create an interactive plan of sites, which allowed the user to select different time periods and then click on the features to receive information about them. Having already created a 3D version of the plans in Sketchup for a different project I decided to use these again in order to save time and improve the visuals.

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I then proceeded to create a mechanism by which clicking on the features would direct you to another “room” where the information was. This was done by creating invisible boxes on the 2d surface and then telling it what to do when a specific box was selected. I then created buttons to go through the different time periods using a similar principle. Finally I wrote the code and made sure it appeared within a box next to an image of the selected feature.

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I cannot give you the exact way in which I achieved this unfortunately for a number of reasons, first of which it would be pages and pages of text and code, but the basic idea is that I played around with the software until I achieved what I wanted: a series of snapshots of the site in 3D that allow navigation through time and that show exactly what we have found with images and text.

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Another project I’m currently working on in instead a program for kids that allows them to interact with a roman soldier and help him carry out tasks. The aim of this is of course educational, and it displays the archaeological finds in a fun and interesting way that kids will enjoy. This one is made using a series of rooms that change every time you click on a certain portion of the map, depending on what the task is, i.e. if the soldier asks you to find the enclosure, then clicking on the enclosure changes the text.

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And these are only some of the ideas that can be made into reality. As odd as it may sound to use gaming software to create archaeology, the potential is great. Games like Assassin Creed or Skyrim have massive cities within them, with which the player can interact, so how much harder can it be to reconstruct entire sites and allow players to walk through them in order to learn more about them?