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Geoinformatics-8-2008
article looking forward to a harmonious future together 3d laser scanning and its 2d partners figure 1: gwithian archaeological landscape, showing in a perfect world, harmony would be applied to 2d survey and a rapidly encroaching 3d perspective. since 2001 projects and organisations like cyark and heritage3d have embraced 3d technologies and tried to better understand and use them within a cultural heritage context. this article discusses three themes: the breakdown of 2d-3d barriers, the merging of digitisation technologies like those of photogrammetry and laser scanning (at least in terms of processing) and finally the increasing attempts to future-proof ancient monuments and historic landscapes by producing ever-more detailed and precise digital records which could survive erosion, vandalism and conflict. a number of practical examples are used to illustrate the points made. by adam p. spring, caradoc peters and andrew wetherelt the bronze age site of gmx also with elevation colour coding. excavated by charles thomas et al 1949 - 1969 . become fuzzy. indeed, for those who feel more comfortable with 2d drawings, a 3d point cloud can generate these as well. similarities between laser scanning and photogrammetry surprisingly such 3d point clouds suffer varying criticism depending on the means by which they are generated. since 1998 the rise of the mid range laser scanner has had many a photogrammetry specialist shaking their fist with a knowing and rebellious, "i've been doing this sort of thing with cameras for years". whilst it is justified to put new techniques through their paces, criticisms of laser scanning have not wholly gone beyond the superficial and have predominately centred on cost. fundamentally laser scanning and photogrammetry are very similar. both capture photometric and geometric information which means they deal with shape, colour, texture and size to produce a cloud of points made up of x,y,z co-ordinates. granted it is possible to produce similar, greatly watered down, results using a well-established survey tool like a reflectorless total station on an automated setting. however it is the speed and amount of information generated which separate potential 3d survey tools out from those traditionally associated with 2d survey plans. a further distinction may be december 2008 rguments about the role of 2d and 3d are not new. with the development of perspective by renaissance artists like leonardo davinci and filippo brunelleschi, the flat medieval art of the church was thrown into disarray. the flat medieval art survived however because perspective can only give an impression of 3d. perspective cannot provide accurate z coordinates for the depth, and so 2d was needed for more serious technical drawings. 3d can also be seen as potentially deceitful or affected by artifice as it was an artistic technique associated with special effects to draw the viewer's eye in a particular direction or to create illusions. a even today people connect 3d representations with cinematic effects, clever illusions or computer games, whilst 2d has remained the domain of the rational and academic. this has clouded people's perception of what digital 3d is about. a perspective in a 3d world can be measured as accurately, easily and readily as from a conventional or digital 2d plan. perceptions, or rather misconceptions, more than anything else hold the archaeological community back from the more widespread use of digital 3d recording. the boundaries between 2d and 3d, in terms of academic versus popular, rational versus impressions have 50
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