Tuesday 3 September 2013

Cathedral slices - Update

Nearly there!  The cathedral bay models created as a guide to English ecclesiastic architectural history for the (very soon) forthcoming Cathedrals and Monasteries from the Centre for the Study of Christianity and Culture are just about ready.  These are something of a record for me in terms of modelling time.  They have taken six weeks from start to now.  To put this into comparison, the model of Wakefield Cathedral I created at the start of the year took almost twice as long and is, arguably, no more complex than these.
Wakefield Cathedral.  Created for an interactive touchscreen by the Centre for the Study of Christianity and Culture installed at the reopening of the nave in 2013.  (This is just the Cathedral as it stands today - I also modelled it in five periods in the past too.  Whew!)  (Image: A Masinton)
Why the huge time savings?  Many reasons.  The chief ones are that Wakefield taught me a lot about modelling Gothic detail and that I had a very good set of measured drawings and architectural details to work from in the form of antiquarian books now out of copyright and kindly made available on Internet Archive.  Chief among these are the volumes of Britton's Cathedral Antiquities, Bond's Gothic Architecture in England and the (slightly eccentric) Robert Billings' Durham Cathedral and the fabulous  Power of Form.  These deserve posts of their own.  For now, go get them yourself.  (I highly, highly recommend you download the original scan data if you want to use these for modelling.)  Like the £2 coin says (quoting Newton's backhanded swipe at Hooke, of course) - 'Standing on the shoulders of giants.'

Romanesque.  c1066-c1180.  Based on Durham Cathedral choir.  Just a bit more geometry to finish. (Image: A Masinton)
Early English Gothic.  c1180-1280.  Based on Salisbury Cathedral (with bits of Whitby).  A little more modelling needed.  (Image: A Masinton)
Decorated Gothic.  c1280 - c1350.  Based on Exeter Cathedral.  Details need to be added (fiddly bits!).  (This one is by far my favourite.  Image: A Masinton)
Perpendicular Gothic.  c1350 - c1540.  Based on Canterbury Cathedral (with a fictional fan vault - my showpiece modelling achievement for this project).  The fan vault needs the 'spandrels' filled and there are details to fix in the geometry here and there.  (Image: A Masinton)

Monday 2 September 2013

The challenge of reconstructing the past - Strangers Hall, Norwich

The challenge of creating a vision of the past which values material and historical integrity is significant.  This is well known but never well understood until an attempt is made to carry this out in practice.  The greater the integrity, the longer it takes to produce a finished vision.  The value of such an exercise is, fortunately, equally significant.

For example, attempt a vision of Strangers Hall, Norwich, in the first years of the seventeenth century as an example.  The subject matter is simply one room, the parlour, but the brief is to reconstruct it as it might have been based on all of the physical, historical and comparative evidence available.  A single image, a snapshot.

What's wrong with this picture?  Discuss.
(The Parlour, Strangers Hall, Norwich, c1600 - Image: A Masinton)
Technical challenges are legion.  There are the very basic but fundamental issues of creating geometry based on data collected in the field.  Scan data, even if it were available at the level of individual objects, is practically useless on its own.  A more conventional approach is called for, but proceeds slowly in the absence of an appropriate set of moulding profiles and rim sections.  Materials are particularly difficult.  Creating a digital version of the material properties of tin glaze Maiolica ceramics, for instance, is difficult, to say the least.  What about a material definition for wood, or pewter, or linen, or felt, or tapestry?  Add to that the issue of the interaction of the material with virtual light sources, and the technical difficulties quickly compound.  What light sources should be used?  A 'simple' exterior sun light - then at what time of day, what time of year?  Interior artificial lighting of the period?  What might these have been?  Tallow?  Wax?  Rush?  What are the photometric properties of each of these light sources and how best the model them digitally?  It is a given that a 'global illumination' rendering model should be employed because it is the most physical accurate simulation of the propagation of light through space, but which approach?  Ideally, an unbiased renderer, of course, but even here there are numerous choices - and if interior lighting is attempted, an unbiased approach may not be suitable simply because the equivalent IES data for historical light sources has never been defined.  To do so would be prohibitively time-consuming.  It is a study within its own right.  Even if daylight alone is used, what about the transmittance qualities of historical glazing?  Again, no quantitative data exists.  And, horror of horrors, what if the windows were 'glazed' with horn?  It quickly becomes evident that the benefits of an unbiased approach are limited because the fundamental data necessary to allow the resulting render solution to claim some historical accuracy simply do not exist.

However, in a way, these issues are trivial when compared to the intellectual issues of attempting to envisage a specific past.  If the project has a well-understood range of technical tolerances, then the technical challenges can be met.  Work in this area is advancing all the time, and the vast majority of scholarship in the field of visualising the past concentrates on technical issues.  This is understandable because these issues are the safest.  These are the ones it may eventually be possible to overcome.

Far more troubling are issues of interpretation.  Even where evidence is relatively rich - where an inventory exists, where items from the inventory survive, where the room remains - understanding and interpreting this evidence is fraught with problems.  Inventories have long been a chimera for archaeologists and historians.  They present a beautiful, itemised report of the contents of a house.  They tell you what items were found in what rooms, sometimes in lovely detail, particularly when it comes to painted cloths, tapestries, linens and cooking ware.  However, while they provide a room-by-room description of the house, when the house itself survives efforts to match the room names to the surviving structure are notoriously difficult.  What the creator of the inventory meant by 'little chamber' or 'parlour' is rarely certain.  Inventories also only present a catalogue of items found in these rooms - not their distribution in space.  If we know that the 'little chamber' contained two beds and three valences, where were they in that room?  Were they piled into a corner?  Were they laid out to offer the most efficient use of space?  Were they arranged to put a visitor at a social disadvantage?  Were they 'presented' to catch the eye?  Were they rumpled and worn, bearing the marks of generations of stories? And what if some of these items do survive - if we have good material evidence?  Some of these questions can begin to be answered.  But trouble remains.  How much has this been altered over time?  What has been lost into the silence of the past?  We may have a bed frame, or a painted cloth, but what don't we have?

These are issues of synthesis.  Evidence exists.  Scholarship, good scholarship, dealing with the evidence already exists - at least a collection of scholarship covering a collection of sub-issues and individual types of evidence.  To create a visualisation of the past is to attempt a synthesis of all the available evidence in light of all the available scholarship.  The resulting image is a map of all the scholarship that has gone before.  It is as much a vision of our own state of understanding as it is a vision of what the space may have looked like at a point in time.

But then, what about all those places in our synthesis where we have no evidence and where we have no scholarship?  Just how very much falls into these uncharted areas of the map becomes clear in the process of creating the image - and this is perhaps where the act of image creation is most valuable, the most dangerous and the most rewarding.  The process of imagining a space in the past is one which is concrete and systematic.  The luxury of focusing on one kind of evidence does not exist.  For the parlour at Strangers Hall, floor, walls and ceiling must exist.  But how were they covered?  And what colours?  How was the room lit and how were the objects within arranged to catch that light?  With what messages and meanings did the owners fill that space?  These are Exciting questions because they bring us closer to a conversation with the people of the past in this place.

But, they are dangerous questions, thrillingly dangerous because to attempt to answer them you cannot rely on evidence and scholarship alone.  You must use your imagination.  Even if all of the pieces of this puzzle survived - to assemble them would require imagination.  But to use the imagination, and to still claim integrity, is to open one's work to criticism.  It is an open invitation to dismantling and rejection.

And that's the point.  A visualisation should never seek to present the past.  It should invite the viewer - any viewer, to enter in and begin to engage, to pick it apart, to find the seams and cracks, and to build on these.  It is to ask the viewer to find weaknesses and to see these as signposts pointing the way forward for a deeper understanding of the past.