PROBLEMS WHEN GENERATING VIRTUAL MODELS REPRESENTING REAL OBJECTS: HONDARRIBIA WALLS

Abstract: This report shows an example of virtual modelization applied to a heritage construction, the walls of the city of Hondarribia. Therefore, it is not a model recreating a building upon hypothetical data obtained from archaeological remains but a true representation of the walls, as we know them nowadays. To accomplish the model, first of all, it is necessary to create a three dimensional geometric model using topographic techniques in order to guarantee the metric accuracy expected to meet further cartographic and restorational needs. After edition job, a mesh-covered model is obtained prepared to be draped with real high-resolution photographic textures which must be geometrically corrected to eliminate the distortion accused by perspective and consequently position the pixels as close as possible to their real place. The process we have just described had been tested in previous projects yielding satisfactory results. However, for greater extension projects as the one in Hondarribia becomes almost untackleable due to the huge amount of information involved. Next paragraphs will show the tips used to solve this handicap