Representing Urban Space: Constructing Virtual Landscapes And Developing Competences

Data collecting and processing

The data about the way of realising the project were collected through the interview method and through participatory observation. During the interview, the student presented the 3D model realised in her project, offered a detailed description of the working manner and, based on the respective information, we continued the series of question within the interview (i.e. semi-structured interview). We applied contents analysis of the data collected as a result of this interview. We analysed the 3D model using visual methodology. Overall, this ascertaining research has the characteristics of a case study.

Participants

In this research, the second author of the paper got involved on a voluntary basis, as a student attending the “Geomatics” Master’s educational programme, who realised the project, analysed her own activity and product, and answered to the interview questions. The other authors of this study, as professors and researchers, were involved in planning and organising the research, in processing, analysing, and interpreting results.

The research material

It consists of the project realised by the student, of the professors’ questions, of the information, answers and opinions provided by the interviewed student.

Task analysis

The students attending this Master’s programme received the task to realise a 3D model of a certain urban area in Cluj-Napoca, a square with the side of 500 m and with the surface of 250.000 m2/0.25 km2/25 ha. During this 3D modelling, the professor recommended the following: to observe the heights; to make sure that the building heights correspond to the ones in reality; to specify the location of buildings (address: street, number); the streets and crossroads to be represented correctly; for individual dwellings, the roofs should be modelled at least as a gable roof; the elements at the margins of the model should overlap the ones in the neighbouring square; to realise a “flight” using the software. The project was to be realised during one semester and to be presented at the end of it, in front of the professor and colleagues. During assessment, the student had to answer questions. The task to realise individually a 3D model offered the premises and optimum context for forming each students’ competences.

Analysis of the process to realise the project

During lectures and seminars students received the needed theoretical and methodological information, as well as examples – all these to enable them solve the task. In both activities, they had opportunities to ask questions addressed to their professors and got answers. For realising the model of the area, the students undergone the following stages: (1) Analysis of the terrestrial surface representation on the orthophotoplan (Fig. 1); (2) Direct observation (in the field) of the surface meant to be modelled (3) Realising the terrestrial surface representation through vectorisation, on the basis of the orthophotoplan (Fig. 2); (4) Elevation of buildings (Fig. 2); (5) Elevation of streets, alleys and sidewalks (Fig. 2); (6) Placement of the imported objects (Fig. 2).

Concerning the difficulty degree of the task, the easiest ones were the first two stages, while the needed time to solve them was about six hours. Direct observation of the area to be modelled was realised through field trips. These observations were necessary to identify the spatial differences between the orthophotoplan and the real urban surface (for instance, new buildings and houses, arrangement of car parks and playgrounds for children). The elevation of buildings was the main objective of this project and had a higher difficulty degree. Students used Street View in Google Earth in order to estimate the height of the buildings, to visualise their form and placement. They downloaded the database for vectorisation in the implicit format of the software, namely .jpg. In order to establish the height of the buildings, they employed two procedures: they either numbered the floors and computed it according to these or they used the facility offered by the respective software, which gave the height by clicking two landmarks (the basis and the top of the building). For the students who had in their areas to be modelled individual dwellings, it was difficult to render the forms of roofs, therefore, at the beginning of the project, it was decided to render them all as gable roofs. To prove the correct overlapping with the neighbouring square (area), several buildings neighbouring the modelled square (area) were represented (Fig. 2). The duration of vectorising all elements in the respective squares (buildings, streets, sidewalks, and green areas) was about six-eight hours.

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Elevation of streets, alleys and sidewalks had a lower degree of difficulty than the elevation of buildings. Students took into account their width, length and height in relation to the terrestrial surface. Representing a crossroads where there was a bridge had the maximum degree of difficulty because it contained many components (the superstructure with the driveway, the infrastructure, the area of the bridge, the area of connecting the bridge to the embankment) and, most of all, the student intended to realise a model with a high degree of similitude. After modelling the buildings, the students took into account the elevation of the ground. They downloaded an elevation model – SRTM (Shuttle Radar Topography Mission) – which was part of the software and imported it into their “stage”, and thus the ensemble that they represented in the respective area/square folded on the elevation model. To realise a 3D model (Fig. 3) for all the vectorised elements, the interviewed student spent about 15 hours, during seminars and at home.

The most difficult and most time-consuming stage consisted of placing objects. This situation was triggered by several causes: high number of objects, form diversity, and increase of the information quantity. The necessary objects (churches, blocks of flats, garages, a gas station, benches, apparatuses for the children’s playgrounds, trees, etc.) were downloaded from the 3D Warehouse that included layouts realised by diverse authors and that allowed for their free or paid import. The objects were imported in the programme used for modelling and were placed where needed. Many objects required that some details were executed (for instance, drawing the curved route of the wires between electrical energy poles; giving the orientation of the street lighting poles). Representing the exterior staircases had a high difficulty degree and was very time consuming, especially for the ones where the stairs were not uniform and the route of the staircase had no straight ramp.

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Product analysis

The project result is a 3D dynamic model that allows for multiple interaction types between author/viewer and model: visualising certain detail aspects using the Zoom in or of the ensemble through the Zoom out; model rotation; movement in diverse directions in the modelled area; changing luminosity according to time and the degree of cloud coverage of the sky (sunset, cloudy, full moon). To ensure a pleasant visual impact and to create strong contrast within the landscape, the author used selected shades of green for green spaces, including for single trees, shades of grey for transport routes (roads, alleys, and sidewalks), and a warm colour (orange) for buildings.

Between the products realised by students, there were differences concerning the used colours, the number of imported objects for representing the area, and concerning the accuracy and precision in representing details. In the 3D model of Calvaria-Mănăștur area, the imported objects were used in a creative manner for urban design, when placing the urban furniture elements, when representing the playgrounds as these places could not be modelled exactly like in reality (for instance, modelling the playground slide). Using in the project very many imported objects had a pleasant visual impact but determined the increase of information quantity up to 1.49 GB and even blockages of the software.

For the self-assessment of the realised 3D model, the professors and researchers involved in writing this paper proposed a 5-criteria assessment grid (Table 1 ) and the student considered that those corresponded to the objectives aimed at during project development. For self-assessment with a high degree of objectivity, we proposed values from 1 to 10. The student completed the self-assessment grid (mean value – 8.4) (Table 1 ). Assessment was realised according to the established criteria, rigorously and involving critical thinking, and not by considering the features of similar products realised by experts.

During the project presentation, the professor addressed questions for checking student’s procedure: How did you realise the scales? How did you realise the curved lines for electrical energy transport? What attributes did you gave the scales? How did you import the urban design elements? In order to check the correspondence with the real space, students were asked if they introduced the address of each building in the Attribute Table.

Analysis of the methods used to analyse and the forms to represent urban space

When studying the urban space, the student used two methods – observation and modelling –, both of them being both research methods and didactic ones enabling the student’s learning as well as forming and developing her competences. Students observed space directly, by walking in the research area and, indirectly, by using photographs and the film available in Google Earth. Concerning the modelling, students realised two models of the targeted urban space: a plan model and a 3D one. The latter, in comparison to the first, had the following features: more represented components and details; a higher similitude to or precision in representation with the real space; it was real; it was dynamic; it enabled a series of interactions with the user (movement, zooming in and out, rotation, light variation, and flight).

Analysis of the student’s motivation and satisfaction

This project needed student’s use of large time resources and considerable focus on the task in order to complete it successfully. The student invested all the necessary physical, psychic and intellectual resources for realising the project because the task was challenging, it stimulated her curiosity and interest for learning a new geoinformational software, by using it. The process of realising the project, of learning, of forming and developing her competences was a difficult one, but the satisfaction of success during the entire activity ensured student’s granting the necessary energy to solve tasks. Students realised that the software was very useful in realising projects. If in this case, they represented a real urban space, in other contexts, they might model virtual spaces.