Different Visions

Back to Laxton tonight, wearing a by now slightly unfamilar hat, to talk to the Laxton History Group about the past excavation and survey work in the village and castle.

I can't resist including one of the CryEngine visualizations of the castle survey in the presentation, and have settled for that produced in CE2:

It strikes me how different the same basic data looks in CryEngine 1:

Nothing deep here, but it strikes me as how CE1 has something of a cartoonish, fantastical feel about it.  Now we may deride that as lack of photo-realism, something that undermines the authenticity of the visualization, and if we did we might have a point.  But there's also something attractive about this, rather like naive art, the studied lack of realism invites a different kind of engagement and reject criticism for not looking real enough.  This might just be my liking for the speed and simplicity of CE1 speaking, but if game based rendering of landscape is about more than simply realism (and I believe it is) then maybe naivety and a simple pallet have something to offer.

Recounting the Landscape: Laxton Castle CryENGINE 2

Part of the aim of "Lasers, Landscapes and Muddy Boots" is to demonstrate the way in which game engines can place us as archaeologists physically within the landscape of our surveyed monuments, albeit virtually.  As a demonstration I've produced this short walkthrough of our survey of Laxton castle, based on field collected GPS data.

Produced using CryTek's CryENGINE 2, it lacks the ludic elements of earlier CryENGINE 1 models of the same site, but has a greater degree of visual fidelity - it looks more like the real thing.  Just the thing to get across the point that standing inside our survey data and rewalking the same fields, getting digital mud on our boots, may bring new insight. In the words of Tilley "To understand a landscape truly it must be felt, but to convey some of this feeling to others it has to be talked about, recounted, or written and depicted."

In the Bleak Mid-Winter...

Winter is truly upon us in the UK, and it seemed appropriate to represent that, and the Christmas season, in some frosty visualisations of Laxton castle, in CryEngine.  It reached -20 centigrade in Laxton last week, and hardy souls ventured out for a public meeting where we discussed ideas for a new venture in public archaeology for the village and its fine castle.

But for now, the holidays are nearly upon us, enough thinking, talking and writing, time for playing and relaxing.

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Laxton CryEngine Photosynth

More playing with photosynth, this time a panorama based on screen grabs from our CryEngine model. I like this, and the simplicity of creation is most impressive.

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Laxton Castle, CryENGINE Anaglyph 3D

Trying to short-cut the anaglyph movie workflow, this short movie of the Laxton Castle game/model uses a single video stream duplicated within Stereo Movie Maker to provide left and right video channels and with the stereo effect created simply by tweaking the registration of the two channels.  It seems to work quite well, although mis-registration is perhaps a little overdone.  Anyway, enough anaglyph for now.

Music "between blue sky and cubicle" by Japanese Seizure Robots on mp3unsigned.com. 

CryEngine Anaglyph 3D

Anaglyph 3D in CryEngine 1 has proven surprisingly difficult to master.  The images below use the same technique as for CityScape (manual panning between captures and Takashi Sekitani's AnaMaker to generate the 3D images from two stills).  Getting the separation between images right is (obviously) crucial for producing a good stereo effect and simple trial and error is problematic.  Time to experiment with cameras in CryEngine.

Although imperfect, I do quite like these images, particularly the final one of Laxton castle looming in the virtual mist.  I wonder if access to a (simulated) third dimension increases the evocative power of the images to render landscape accessible?

Playing with Perception: Panoramas in CryEngine

Photographers have experimented with panoramic cameras since the Daguerreotype. Panoramas provide a fresh perspective on landscape that is both disconcerting (places and structures appear to assume different and unfamiliar relationships to each other in a panorama) and yet familiarly complete (the whole landscape is there as we might see it when we change our view by turning on the spot).  Static panoramic photographs are also strangely beautiful, and often form striking artistic impressions of land and cityscapes.

Moving panoramas have become fashionable on the web (or perhaps have come and gone in fashion) as digital photography and software such as Apple's Quicktime VR supported their creation and display.  Google Streetview is the ultimate example of this, and assumes a strange beauty when deconstructed to it constituent images.

Games-based visualisations are at first glance locked to the fixed, first-person viewpoint of the avatar, a naturalistic, view, but limited in its artistic pretensions...

Following on from playing with the camera in CryEngine to simulate the effects of changing lenses on a 35mm camera, it struck me that combining a series of static "photographs" of the landscape using appropriate software (I used the free, and rather wonderful Autostitch) would enable the creation of static panoramic images.  So here are two, of Laxton Castle.  These are 360 degree panoramas each created from approximately 30 "photographs" of the landscape from a fixed location, but each with a different view.  The results are quite pleasing and provide a different perspective on landscape, escaping from the avatar, as it were.

Playing with Perception: Camera Control in CryEngine

Photographers know well that changing lens provides access to different creative effects, from the panoramic impression of an ultra-wide angle lens to the compressed perspective of a telephoto.  CryEngine's fixed 60 degree diagonal field of view is approximately the equivalent of the human eye, roughly the same as a 40mm focal length lens on a 35mm film camera.

While the avatar is restricted to this fixed view angle, playing about in Sandbox it is possible to create multiple cameras, each with its own field-of-view of up to 180 degrees. Here, by way of example, a range of fields of view from the same viewpoint, each with the approximate 35mm film focal length equivalent.

5mm (180 degrees)

24mm (80 degrees)

40mm (60 degrees)

200mm (10 degrees)

400mm (5 degrees)

1600mm (1.7 degrees)

The artistic possibilities are immediately obvious, and choosing a narrow field of view (reaching for that telephoto lens) has the useful and realistic effect of compressing both perspective and depth of field.  Interesting potential here for cinematic style zoom and dolly combinations.  Time to experiment.

Building Sterile Landscapes

Together with colleges at Birmingham and Nottingham I have spent a good many years exploring the earthworks of Laxton's fine medieval motte and bailey castle.  For those who are interested many of the details of our work are available on a dedicated website and in fact some of my early game-based visualisation experiments, using the Medieval Total War engine, were focused on Laxton.While that was altogether an unsatisfactory experience it did force me to consider more sophisticated technology, and so to CryEngine.

Our fieldwork at Laxton has always been an ad-hoc affair, student and community focused, and one of the outcomes I would still very much like to achieve is to return a version of that work to community ownership.  I've ruminated on whether game-based visualisation is one was to achieve that.  A game provides an elegant, accessible portal into the technicalities of survey, and one that can seamlessly move from real and now to then and maybe (back to that five-dimensional space).  However, recent reading is causing me to reflect on the whole game experience.  What draws us in to the game world? Dan Pinchbeck's work reminds us that it is narrative and particularly elements of narrative beyond the ludic, that capture attention.

So, while our present game-based visualisation of Laxton attempts to recreate the now and real of the monument and landscape, and entice users into exploration and discovery, rather than passive reception, this is on one level a sterile vision, the roving eye of the avatar moves over the landscape without motive or intent.  Perhaps what is needed is a narrative to motivate and inform.  Co-opting not just the technology of game engines, but the ludic and the narrative, now there is a challenge...



Pinchbeck, D. 2008. Story and Recall in First Person Shooters. International Journal of Computer Games Technology. 

Unity

I've recently been working with Unity Technologies Unity3d game engine. Unity is attractive as the basic version is free to download and use, and the editor pretty easy to get to grips with (although I admit to struggling to master camera control).  Its great strengths are a graphically stunning 3d engine and the ability to compile the same basic level for delivery as a standalone file for a range of platforms or via a web-browser plug-in.  Since this is a stripped back game engine, not hung on a particular game, the combat element that is so hard to get around in CryEngine is wholly absent, a refreshing change.

Unity appears to work well with greyscale heightmaps for defining real-world terrain (although confusingly the editor appears to mirror the x and y co-ordinates of the original image) and there are a range of pre-fab objects and textures to make level creation possible straight from the box, so to speak.  I'm impressed and so will be working to get to grips with the finer points of Unity in the hope that it may provide a better solution than my favourite, CryEngine, in the longer term.

Dynamic Lighting

One of the things I particularly like about CryEngine 2 is its implementation of dynamic lighting, great for seeing the effects of changing sunlight on the landscape.

This simple video sequence shows a static view of Laxton Castle from sunrise to sunset, compressing a day into 90 seconds.  True, not much happens but the lighting effects at dawn and dusk are great and there is considerable potential for exploring interplay of light and landscape further.

First Steps in Source

Half-life 2 is one of my favourite games, there is just something about the look and feel of the landscapes, the atmosphere and the character models that feels right and I've been keen to try it for archaeological visualisation for a while.

However, the brush based modelling used by Half-life makes use of terrain models derived from greyscale heightmaps problematic. Inspired by discovery of Dan Pichbeck's excellent Chineseroom and his AHRC funded Half-life 2 mods Dear Esther and Korsakovia I felt it was time to grapple with the problem again.  A little bit of searching turned up a really useful tutorial at Interlopers.net and a link to DispGen, a tool for deriving Half-life brush-based displacement maps from greyscale heightmaps.  Initial results are promising, and it proved relatively easy to get our Laxton Castle terrain model into Hammer and on into Half-life 2.  Scaling is a bit of a problem, solved for now by using an NPC as a rough scale.  Early days, but the potential for using Half-life for visualisations based on real terrain is quite exciting...

Laxton's Castle: A Virtual Fieldtrip

Laxton Castle in Nottinghamshire is a fine medieval motte and bailey, once supporting a substantial masonry castle which served as the centre of the administration of Sherwood Forest.  We have surveyed the earthworks over a number of years, and our initial GIS-based visualisations provided much of the impetus for testing out the alternative route of game-based visualisation.

As we've worked on the Laxton model we have begun to think about and explore ways in which the game paradigm can be exploited to encourage exploration as well as simple for visualisation.  A first step is to embed within the terrain model vestiges of the masonry curtain walls and towers, based on the surveyed remains and, realistically hidden in the vegetation.  The first question for a new gamer is "what are you looking at and what evidence can you find for the original form of the castle?"   I feel that we are creating the first draft of a kind of virtual fieldtrip, encouraging users to explore the game landscape and learn from it just as one would confronted with the real thing.