True grid

Abstract

The Renaissance architect, moral philosopher, cryptographer, mathematician, Papal adviser, painter, city planner and land surveyor Leon Battista Alberti pmided the theoretical foundations of modem perspective geometry. Alberti's work on perspective exerted a powerful influence on painters of the stature of Albrecht Diirer, Leonardo da Vinci and Piero della Francesca. But his Dellapittura of 1435-36 contains also a hitherto unrecognized ontology of pictorial projection. We sketch this ontology, and show how it can be generalized to apply to representative devices in general, including maps and spatial and non-spatial databases.