Solid modelling using CAD technology is extremely useful for the representation of architectures, structures and flow-production items, both for surveying and designing. This applies in particular to items having complex shape and volume.

Three-dimensional representations supply the virtual image of the object under observation, and this can be used for a number of applications. For instance, it is possible to obtain orthogonal, assonometric and perspective views, as well as sectional views, calculation of volumes, verification of viability and components’ assembly.

Moreover, three-dimensional modelling is applicable to land surveys, for the representation of newly built areas and for environmental or archaeological surveys. The land is usually represented by isolines or spots with a pre-established density, and it is modelled as if it were a plan by means of numerical calculations that interpolate the surveyed data. The representation obtained can then be processed again in order to carry out morphological and environmental studies such as cleavage analysis, slope exposure and the reconstruction of the whole stratigraphy of archaeological excavations.