Conventional Cast Shadows in Projection and Representation over Time: Semantic Exploration through the Drawings of Rossi and Grassi

This article examines the representation of shadows in orthographic projection in architecture, exploring the semantic relationship between shadows and architectural form over time. The term itself, derived from the Greek orthos (straight, correct) and graphein (to write, to draw), suggests the idea of a right or true drawing, beyond its strictly geometric definition. Can a graphic convention as geometrically fixed as the conventional cast shadow nonetheless express a particular architectural thought? The study focuses on the drawings by Aldo Rossi and Giorgio Grassi in the 1970s–1990s as emblematic examples: both employ the same convention yet deploy it with different intentions, revealing how shadow representation can serve as the vehicle of architectural thinking.