Georgopoulos, Andreas
reconstruction, the AutoIDEA, which operates within AutoCAD. Several typical house forms were determined from the
amateur photographs (Figure 2 -left) and these were constructed as 3 -D orthogonal solids, including their roofs as sloped
planes (Figure 2-right). A typical landmark of the old settlement were the numerous windmills, situated on top of the
hill. For their representation a cylindrical solid with conic roof was also constructed. This process yielded the three
dimensional representation of the buildings, ready to be included in the final 3-D scene for rendering.
Figure 2. An old amateur photograph of a typical house (left) and a 3-D wireframe model of a house (right)
The next step was to merge all previously described data. As they were all compatible, i.e. vector representations in
AutoCAD environment, this was quite a straightforward task. At first the planimetry was merged with the DTM, while
the digitised roads served as breaklines. Subsequently the outlines of the buildings were introduced. With their help the
bases of the houses were “cut” into the DTM, also as breaklines. In this process the windmill bases were specially
treated, as they were of a different shape.
The 3-D wireframe was then completed by the addition of the solids, representing the man made constructions, i.e. the
houses, the windmills and the bigger buildings of the old settlement at their appropriate positions. The result of this
operation was a 3-D wireframe model of the settlement, as close as possible to the pre-earthquake reality. This
wireframe was then draped with suitable rendering attributes, in order to produce the final 3-D visualisation.
4 PRESENTATION OF VISUALISATION
The data collected and processed as described above formed the basis of the final visualisation. As already mentioned
there are numerous means of representing and visualising 3-D data. The choice of the right one each time depends on
the scope of the final visualisation.
Figure 3. The 3-D wireframe model of the settlement
288 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B5. Amsterdam 2000.