The aim of this hands-on activity is to derive the rules to draw the perspective image of 3D object in a plane starting from the observation and the usage or the Dürer's glass, one of the first tools built to draw in perspective.

The students are then provided the Barozzi's plane tool, by means of which and applying the distance points method, they are requested to draw the perspective image of a polygon lying on the ground plane. As a final step, the students are led to verify that the image obtained is the same as what they would have obtained using the Dürer's glass. The advantge this time is to work on a plane other than in the space.

With easy demonstrations based on elementary geometry, the equations of a one-point perspective transforming point A’ (x’,y’,z’) in the 3d space into its perspective image A(x,y) in the perspective plane can then be derived. A final request for the students is to calculate the perspective image of a solid through the equations and to verify that is equal to what would be obtained using the Dürer's glass.

Hands-on activity presentation (ita)

**Guiding forms**

Perspective (ita) |