Valeria Vitale from King’s college explained the importance of documenting the underlying technological and methodological processes of 3d visualisations. Some “beautiful cultural heritage visualizations” are like books without titles, dates, authors or references … documents that have no values in the historical debates.
She discussed the London Charter initiative and CIDOC-CRM RDF modelling approaches. Based on her own work on reconstructing some houses of Pompeii, she illustrated how untrusful can some historical engravings be, showing the difference between various engravings and photographs.
Uncertainly level must be attached to each element of 3d reconstructions. Vitale explained that Piranesi himself was using uncertainty level to document his reconstruction.
Then she presented her own proposal for 7 levels of uncertainty
LEVEL 1. The element is still in situ and its dimension and position can be measured
LEVEL 2. The element is not in situ but it has been visually documented in the past and the document is still available
LEVEL 3. The element is not in situ but can be geometrically derived form the surviving elements
LEVEL 4. The element is not in situ but it can visualized according to well accepted standards and precedents
LEVEL 5 The element is not in situ but it can visualised according to the modellers’s experience, knowledge and intuition
LEVEL 6 The element is not in situ and it has been added for communicative purpose
Linked with the Venetian cases.
Although Vitale presented cases of uncertainties and inconsistencies not directly linked with Venice, many Venetian documents are also untrustful
– Canaletto’s paintings of the Grand Canale, despite the fact they they are done using a camera obscura, are known to be much larger than the real thing to please the tastes of the English “tourists” that bought them.
– Maps of the Venetian Arsenale are known to be always wrong for ensuring military security
– Documents in the State Archive (work contracts, tax declaration) tend to declare smaller number of possessions / employees to avoid paying taxes.