Three dimensional visualisation

As well as photomontages, interviewees showed a great appreciation for 3D visualisations, especially, image-draping technique for ground modelling. This can be simply modelled, represented in a great level of detail, and physical three - dimensionals. A community forest officer, Interviewee I in Forest Organisation Group claimed that;

Image draping over terrain models is definitely useful. It is more valuable and gives the best view. And QuickTime view can be used in viewpoints at the human eye level; whereas, image draping over terrain is good for bird’s eye and general overview.

Based on DTM64 aerial images are draped on to DTM and it gives a sense of topography and reality of the context (Figure 6.3).

Figure 6.3 Images Draping onto DTM

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Digital Terrain Model, A digital elevation model is a digital model or 3D representation of a terrain’s surface- commonly for a planet (including Earth), moon, or asteroid-created from terrain elevation data. There is no common usage of the terms digital elevation model (DEM), digital terrain model (DTM) and digital surface model (DSM) in scientific literature.

Moreover, interviewees from Private Landscape Consultant Group indicated that this was an efficient form of visualisation used in planning. Interviewee I pointed out that there are much greater benefits to be gained from having an image draped model in forest management. Therefore, aerial draped models give a great utility of forest changes, measuring impact, and terrain formations in a study area.

In addition, providing a pre-set path simulation (animation) with the image draped models, gives a high level of detail because it is based on topographical surveyed DTM from Ordnance Survey. When up-to-date aerial imagery is draped onto the DTM, the computer visualisation is able to produce a credible representation. Most interviewees indicated that they preferred 3D models with aerial photographs to two dimensional mapping. For instance, a Community Forest Officer, Interviewee I continued;

If you have a lot of money you can use VR but I don’t think we are far enough down the line of virtual reality at the moment. Specially, texture limits, rural elements, trees and woodland, trying to show the best of the woodland is hugely time consuming. Whereas if you are doing a brick building which has been modelled for an architect’s drawing, that’s the fixed plan whereas woodland takes a huge amount of time but still never quite get it right. We are modelling nature and it changes.

On the other hand, the three-dimensional models created by physical geometries are regarded as an expensive visualisation and, often, time-consuming to produce. However, unlike modern video gaming industry, 3D visualisation in planning has a comparatively low level of realism.

It is considered that there is a cost and effect justification point where cost meets professionals’ and clients’ needs. Nevertheless, when cost goes beyond a certain point, cheaper media are likely to be preferred.

For instance, 3D physical geometry created visualisations can be replaced with raster image generated 3Ds such as Panoramic VR or QuickTime VR and photomontages conserving the photographic quality and provide significant cost savings. This was illustrated thorough a comment from an associate landscape architect, Interviewee A;

They are all useful for different reasons. Real-time rendering visualisations can be more fun. I think because you have to involve pressing buttons, navigate, controlling cameras with keyboards and mouse, children will love it but some public may not be able to use it particularly older ones. I think you’ve got to have some images because an image is really important for people to have a piece of

paper such as photomontages, plans, and perspectives. It is quite important to have it on paper to discuss, to talk and to print out.

Some interviewees preferred 3D visualisations rather than 2D. They claimed that 3D visualisations read better for communication in planning. This is an associate landscape architect, Interviewee E’s point;

I don’t like the flat on type of montages. Because if it is flat (2D) and when you put things in it, it isn’t always right you will get distortion. That’s why I like the three-dimensional approach. You are looking at something in real and it shows real whatever it is. If you show this in two dimensions such as sections or elevations it becomes hard to understand. That’s why I think it is a way forward. I think sections and elevations will not be used in planning. One time, we will draw plans, sections,

elevations and we will show sketches. We do normally use sections of a small area which isn’t telling you much. I know in some occasions sections are good but in most circumstances, if you have three dimensional visualisations it explains a lot more. It is very important.

In addition, interactive layer mapping tools were presented to the interviewees. The majority of interviewees agreed that the tool was useful particularly in the consultation process because viewers can selectively choose the information they see. However, it is still two dimensional mapping; therefore, interviewees also indicated that it could not be easily read by lay people. Private Landscape Consultant Group recorded opinions on layer mapping as below;

The plan you showed me at the beginning - the plan in which you can turn layers on and off - A lot of people still cannot read those plans. I know it is hard to understand, but a lot of people cannot read the plan because people don’t know how to orientate themselves with plans. When you learn how to read a plan, you can understand. But some people cannot read ordnance survey maps either.