Leonardo’s Spatial Grammar: A CAD Reverse-Engineering Analysis Corpus: Leonardo’s CAD, Leonardo’s Rulers, Leonardo’s Score – overview

This Zenodo record (DOI: 10.5281/zenodo.22045814) presents an open-access academic publication by researcher Giancarlo De Leo, published on August 21, 2026.
Work Overview
* Title: Leonardo’s Spatial Grammar: A CAD Reverse-Engineering Analysis Corpus: Leonardo’s CAD, Leonardo’s Rulers, Leonardo’s Score
* Author: Giancarlo De Leo
* Subject / Category: Art History, Digital Humanities, CAD Reverse-Engineering, Perspective Geometry
Main Thesis & Abstract Summary
The publication presents a unified analysis of three key works by Leonardo da Vinci: the Annunciation, the Adoration of the Magi (Uffizi drawing 436 E), and the Last Supper.
It challenges the long-held assumption that Leonardo mechanically applied the standardized Albertian square-grid perspective (or that deviations were merely errors/license). Instead, using CAD reverse-engineering, inverse geometry, and anthropometric verification, the author argues that Leonardo progressively developed a dynamic, metric-modular spatial grammar.
Key Findings Across the Three Case Studies:
* Annunciation (Leonardo’s CAD):
   * Features an “inserted geometry” prototype structured by a module q (half a Florentine braccio).
   * Details like rusticated blocks and floor tiles form an explicit orthogonal coordinate system calibrated to the Virgin’s seated body (where the horizon matches her shoulder height).
* Adoration of the Magi (Leonardo’s Rulers):
   * Replaces the traditional square-grid hypothesis on Uffizi sheet 436 E with a generative 4:3 rectangular grid anchored to the Florentine braccio.
   * Shows how this 4:3 grid resolves long-standing geometric distortions and integrates golden triangle and pentagonal geometry in the stair structures.
* Last Supper (Leonardo’s Score):
   * Demonstrates a mature stereometric polyphony controlled by a single generative module utilizing rhythmic ratios like 1:4:1, 2:1:2, and 1:6.
   * Reconstructs the painted space as an immersive, reassemblable 3D prism harmonized directly with the physical architecture of the Santa Maria delle Grazie refectory.
Core Methodological Principle
* The “Aristotelian Obvious”: The research strictly relies on visible, measurable, and falsifiable spatial evidence within the paintings themselves (e.g., tapestries, coffers, stairways, arcades functioning as embedded “rulers”) rather than esoteric theories or symbolic speculations.
* Paintings as Spatial Simulators: The study frames Leonardo’s perspective not as an abstract, rigid rulebook, but as an operational, constructible architecture designed for spatial simulation.