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.

Exploring Visibility and Atmospheric Occlusion in CryEngine

The role of visual appreciation of landscape has taken a leading role in the archaeology of landscape, encouraged both by theoretical approaches and the utility of GIS softwares for automatic analysis of the visual characteristics of large landscapes.  Various writers have critiqued GIS studies of visibility and proposed enhancements to and refinements of visibility studies (eg. Llobera 1996 and 2000; Ogburn 2006).  In essence arguments for the refinement of visibilities studies focus on the need to appreciate the impact of range, view direction and target size on visibility. Additionally, a number of authors have pointed out the shortcomings of both theoretical and practical approaches to visibility studies, in particular the fact that many studies ignore or misrepresent the potential impact of vegetation and past vegetation patterns on landscape and visibility. 

I have been experimenting with using CryEngine to model different degrees of visual occlusion of landscape, based on atmospheric fog and rain.  Sandbox conveniently allows varying vegetation scenarios for the same landscape to be stored as layers that may be turned on and off to explore the visual impact of changes in vegetation.  Sandbox's environment controls allow alteration of the character, density and occlusion distance of atmospheric fog and addition the impact of rain on visibility may be simulated through particle effects.  The graphics here illustrate CryEngine simulations of the effect of increasingly dense atmospheric fog (with view distance decreasing from 200m to 500m) and the addition of rain on visibility of Stonehenge as viewed from The Cursus, a distance of just over 2km, and can be compared with a traditional GIS-derived two-dimensional viewshed diagram from the same location.

I think this approach has some potential for exploring changing visibility in landscapes where views and indivisibility are considered significant.  I'll be exploring different vegetation patterns in a similar light in the near future.

Llobera, M. 1996. Exploring the topography of mind: GIS, social space and archaeology. Antiquity 70, 612-22.

Llobera, M. 2001. Building past landscape perception with GIS: understanding topographic prominence. Journal of Archaeological Science 28, 1005-14.

Ogburn, D.E. 2006. Assessing the level of visibility of cultural objects in past landscapes. Journal of Archaeological Science 33, 405-13.

Technological Advances in Landscape and Heritage Management Recording

Here, for the record, my presentation given at Technological Advances in Landscape and Heritage Management Recording in Dublin on Friday.  An excellent, useful and enjoyable day with some very interesting presentations, particularly focused on high resolution airborne and terrestrial lidar.  I was really taken by the work of Dr Dave Walker on the Nottingham caves (good enough to deserve its own post, so more later) and the Scottish Ten, mysterious name, but great work, again deserving its own post. Since I managed to give the wrong version of my presentation, anyone interested in what I had to say will get a fuller picture from the below...  

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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Little Gidding

This short movie shows work in progress on visualising Eliot's poem Little Gidding in CryEngine.  It gives some sense of what I am trying to achieve, a sort of meditation on landscape and time using Eliot's words and the real landscape of Cambridgeshire. Much more to do, and not sure as a concept if it works or not, but as an experimental use of game engines it has some novelty at least.

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Little Gidding

history is a pattern

Of timeless moments. So, while the light fails

On a winter's afternoon, in a secluded chapel

History is now and England.

TS Eliot's Little Gidding is my favourite poem by my favourite poet.  Written in wartime, it conveys a timeless Englishness and a profound sense of landscape and time.  Little Gidding is of course the location of a secluded church, home to an Anglican religious community founded by Nicholas Ferrer in 1625.  Both the church, the community and the landscape inspired Eliot.  Inspired by Dan Pinchbeck's Dear Esther I have set about translating this wonderful poem into a narrated, free-form landscape-based game in CryEngine.  The landscape of Little Gidding is developed from Ordnance Survey data (some rough drafts below) and the church is to be modelled in SketchUp using crowd-sourced photography.  I'm using the version of the poem spoken by Paul Schofield for the BBC in the 1980s as the basis for the narration.  The imagery of the poem will guide development of the landscape and at present I'm considering whether to fragment the poem (Esther style) so that players encounter the verse in random fragments as they explore the landscape, or to create a guided path around the landscape, revealing verse fragments and imagery in correct order.  Eliot himself inspires the approach:

If you came this way,
Taking the route you would be likely to take
From the place you would be likely to come from...
If you came this way,

Taking any route, starting from anywhere,
At any time or at any season,
It would always be the same

Why on earth do this?  Well partly in homage to Dear Esther, which I love, and partly to explore the game form as a method for encountering text and landscape.  The idea of uniting Eliot's text with its inspiring landscape intrigues me and I wonder, does such rich text bear mediation in the game form?  I also like the idea of subverting CryTek's violent game engine to the purpose of presenting Eliot's most meditative war poem (well poem written in time of war).  More later.

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Spherical Projection

An office move has uncovered our old Elumens Vision Station, which sat running no more than the Elumens demonstration movies and a copy of EventScope for most of its life as no-one ever really got to grips with its peculiarities. A quick investigation revealed Elumens' TrueFrame software still installed.  The challenge was obvious, can CryENGINE be persuaded to generate spherically projected images for the VisionStation?  In the absence of SPI-API (Elumens are now long-defunct) which offered live conversion of Open-GL output I resorted to generating static images (four per spherical image) from a custom camera in Sandbox and stitching these together in TrueFrame. It works (as you can see) although the sky is a little flaky (possibly a misaligned camera; something to investigate).  However, the prospect of trying to produce animated output from CryENGINE, with limited Sandbox camera control and no native animated output, fills me with dread; something for a very rainy day...

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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 Movie

After considerable fiddling I appear to have produced an anaglyph 3D movie generated from CryENGINE.

The movie was produced by creating a camera path in Sandbox, running the camera in an out-dolly along the path at 1/8 of its full speed and using Camstudio to capture the results as an AVI (if only AVI output wasn't broken in Sandbox).  The master AVI was exported to an image sequence (5300 frames) using VirtualDub.  The frame sequences were then duplicated (one for left eye and one for right eye) and, through trial and error, a step mismatch was introduced to simulate the view from parallel camera tracks.  It worked out that a mismatch of 10 frames created a good stereo effect.  The mismatched image sequences were then combined to produce a single anaglyph AVI using Masuji Suto's excellent Stereo Movie Maker.

Does it work?  Most of my colleagues can see the 3D effect, so I guess it does.  Improvements required are a higher native resolution (I've upscaled this to 720p from the original 360) a more adventurous camera path and and some work refining the simulated parallel camera paths (requiring a higher frame-rate for the video capture to enable more subtlty in creating the mismatch).

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?

Strange Visions

More strange visions, this time panoramas of Stonehenge assembled in CityScape (top) and CryENGINE (below).  These strange mournful visions of the stones are quite beguiling.

For comparison, here below, a real photographic panorama of the stones, courtesy of the BBC.

BBC Stonehenge Panorama

I'm quite taken with the idea of using game engines to create artistic renderings of landscape, extending into the impressionistic, even the surreal.  Why should we be chained to photorealism by the intense graphical renderings of modern games. More experimentation, less realism...

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.

Redhill: Visual Impact on an Archaeological Landscape 3

A final version of the Redhill visualisation completed in CryEngine. Better in the end than I anticipated, but still problematic, particularly in terms of placing digital vegetation to mirror the real-world, which becomes crucial when local vegetation can radically alter mid-range views and visibility.  

8-bit CryEngine texture mask derived from a colour
air-photograph co-registered with the terrain model in ArcGIS

CryEngine terrain model, textured using
an air-photo mask, (top) without
and (below) with vegetation models.

One innovation that I am pleased with is using air-photographs to create Sandbox texture masks to rapidly add low-resolution landscape detail.  Here I've used a colour original air-photograph, co-registered with the DTM in ArcGIS, to create an 8-bit monochrome mask, with features textured on other layers such as trees, excluded.  The end results add useful detail to the CryEngine rendered terrain and makes placement of assets such as trees and hedges easier. 

I think based on these results, and the development of a fairly robust and rapid workflow from GIS to CryEngine I'd be confident to use CryEngine to take on more ambitious GIS derived visualisations, particularly where good quality asset models already exist.

Redhill: Visual Impact on an Archaeological Landscape 2

A quick update of work on the Redhill visualisation.  The model of Ratcliffe Power Station is taking shape, cooling towers in place, buildings and main chimney to add.  I'm quite pleased with the results of adding particle effects to the cooling towers, although the "smoke" needs to be white, not black, as it is in fact water vapour.

Overall the visualisation is working out better than I had anticipated, although the proof will still be comparison with ground level photographs.

Redhill: Visual Impact on an Archaeological Landscape

I've been working on a visualisation to attempt to illustrate the visual impact of a proposed development on an archaeological landscape.  Such work is usually the preserve of landscape architects working with high-end CAD and landscape design software (see for example Griffon, et al in press).  In this example I've attempted to use CryEngine as a low-cost visualisation tool to present a ground-level view of the landscape in order to assess likely visual impact.

We're looking at the hinterland of the Roman cult site at Ratcliffe on Soar, Nottinghamshire.  This is an archaeologically important landscape (protected as a Scheduled Ancient Monument) which is poorly understood and substantially affected by previous developments including railway, power station and major roads.  The issue is the extent to which proposed future development will intrude on what remains of the unspoilt landscape setting of the Roman site.

Initial work was carried out in ArcGIS, building a terrain model and a series of land use masks derived from Ordnance Survey mapping.

GIS derived terrain model and land use mask for use in CryEngine

The terrain and masks were then used in CryEngine to build a basic landscape with correctly located river, woodland, fields and building placemarkers.  First results are below.  The overall visualisation now needs considerable work to add existing buildings, the development and landscape detail in key areas.  Results will be tested against ground level photographs for general reliability.

A selection of images from the initial CryEngine visualisation showing
the rivers Trent and Soar, woodland and building placemarkers.

I'm not convinced that CryEngine (or my modelling skills) are up to the task, particularly with the approximations in vertical scaling inherent in CryEngine, but it's an interesting project, and worth a try.

Griffon, S. et al in press. Virtual reality for cultural landscape visualization. Virtual Reality. 

Waun Ddu: Experiments in Terrain Texturing in CryEngine

One of the things that I have found a niggling problem in CryEngine (and for that matter in every game engine I have tried) is creating natural looking texture-mapped landscapes.  CryEngine offers a number of ways to achieve this, including painting textures directly onto the landscape, automatic mask generation based on elevation and slope and use of custom texture masks.  Using automatically generated masks one is restricted to simple slope or elevation classifications, based on the in-game terrain model (with its degraded resolution).  This is rarely wholly satisfactory, but at least better than the carpet-like effect of a single texture.

While it seems that texture variations based on products derived from the terrain model might be desirable, and represent real-world landscape change, as vegetation and landcover usually do vary in such a way, I'm keen to keep the original higher resolution terrain model as a base for these.  I've experimented with a variety of derived products from a GIS-based digital terrain model, in this instance based on 0.5m resolution airborne lidar data for the Medieval motte and Roman fortlet at Waun Ddu near to Llandovery in the Brecon Beacons.

DTM derived layers, hillshade, slope severity and solar radiation

Using ArcGIS I generated slope, hillshade and solar radiation maps of the terrain model.  These were used to create texture masks for CryEgnine (for a 512 x 512 terrain model Sandbox requires texture masks of 4096x4096 pixels in windows bitmap format).

The results are interesting.  Individual DTM derived texture masks produce more subtle terrain texturing than using Sandbox's built in tools.  The solar radiation mask (based on the amount of sunlight received at each location in the terrain model) is particularly useful for showing vegetation variations, which are often based on such factors.

Terrain variation based on solar radiation map

Terrain variation based on slope severity

The masks also work well together, with a plain base texture using slope to add rocky outcrops and solar radiation to vary vegetation

Combined base, slope severity and solar radiation texture mapping

This looks like a good way of adding naturalistic variations in terrain texture based on real topographic data and I shall be experimenting more with this in future.

Painting the Landscape

A request to provide images of Stonehenge with the Cursus barrow group in the background had me pondering the limitations of my Ordnance Survey based terrain model, which of course includes no such details.  In the absence of lidar terrain data for the study area (unless of course English Heritage would like to hand some over)  I've come up with an inexact compromise.

Using the Ordnance Survey mapping, which shows barrow locations, I've created a binary mask in ArcGIS in which the earthworks of barrows are shown in solid black.

Imported into CryEngine as a texture mask, and with a suitably garish texture, this serves as a visual guide for manually tweaking the terrain with Sandbox's terrain modification tools, in effect painting the barrows on to the landscape.  With sensible textures restored things begin to look reasonable.

The results are not so bad, with correctly located barrows that, with care, can be sculpted into approximately the right size and profile.  Better of course to begin with accurate survey data, but for now at least this meets the requested need.

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.