Modular Perspective is a geometrical method of perspective developed by the Mexican architect and researcher Tomás García-Salgado. It provides a systematic way of locating, constructing and measuring three-dimensional spatial Forms directly within a perspective image by relating them to a modular spatial coordinate system.
The method is particularly significant because it can operate in both directions. It can be used to construct a perspective image from known spatial dimensions, but it can also be used inversely to recover dimensions, positions and spatial relationships from an existing perspective image.
García-Salgado developed Modular Perspective principally in relation to architecture, geometrical perspective and spatial design, although its applications extend to the analysis of drawings, photographs, paintings and other perspective images.
Tomás García-Salgado and Modular Perspective
Tomás García-Salgado is an architect, researcher and former member of the Faculty of Architecture at the National Autonomous University of Mexico (UNAM). He has written extensively on perspective geometry and developed Modular Perspective as an alternative geometrical method for the construction and analysis of perspective.
His work treats perspective not merely as a drawing convention but as a geometrical relationship between the observer, spatial object and perspective plane. A central concern of the method is how three-dimensional position, size and distance can be expressed and read within the perspective image itself.
García-Salgado summarises the underlying conception of his work through the idea that perspective provides a geometrical representation of human vision. Modular Perspective consequently seeks to establish a geometrical correspondence between the spatial environment seen by an observer and its representation upon a perspective plane.
The Geometrical Model
The distinctive feature of Modular Perspective is its own geometrical model of space. García-Salgado describes this model through three principal planes.
- Plane of Symmetry X — one of two mutually related spatial reference planes;
- Plane of Symmetry Y — the second spatial reference plane, operating with the first to establish a coordinate framework; and
- Perspective Plane — the plane upon which the perspective image is projected and constructed.
The two symmetry planes establish a spatial coordinate system through which the three-dimensional position of a point can be defined modularly. The Perspective Plane is positioned in relation to this system and to the observer and receives the projected perspective image.
The system therefore establishes a direct relationship between Object Space coordinates and Perspective-Space position.
Object-Space position → Modular coordinates → Perspective projection → Perspective-Plane position
The Module
The module provides the fundamental unit through which spatial dimensions can be organised and transferred within the system.
Instead of treating the perspective drawing merely as an arrangement of converging lines, Modular Perspective relates positions within the image to a measurable three-dimensional spatial framework. Distances, heights and lateral positions can consequently be considered in relation to an underlying modular structure.
This makes the module both a construction device and a measurement device. It helps establish where a Form should appear in perspective and, conversely, can assist in determining the spatial relationships represented by an existing image.
Constructing Directly in Perspective
One of the important capabilities of Modular Perspective is the ability to work directly within the perspective view.
Traditional architectural perspective commonly begins with orthographic information such as plans and elevations and then transfers the required measurements through a perspective construction. Modular Perspective can also generate perspective from such information, but García-Salgado developed the method so that geometrically controlled Forms can be designed, positioned and dimensioned directly within perspective.
This allows a designer to explore the appearance and proportions of a building or spatial Form while remaining within the perspective image rather than continually moving between plan, elevation and perspective.
Perspective as a Design Space
This makes Modular Perspective particularly interesting for architectural design. The perspective image is not restricted to being the final illustration of a design already completed elsewhere. It can become an active geometrical space in which the design itself is developed.
Preliminary spatial Forms can be sketched in perspective, their relative dimensions and positions examined, and their proportions modified while their three-dimensional relationships remain geometrically controlled.
The perspective drawing can therefore function simultaneously as a means of representation, spatial reasoning, measurement and design.
From Plans to Perspective
Modular Perspective can also perform the more familiar operation of generating a perspective view from known geometrical information.
Plans, elevations or other dimensional information describing a building or object can be related to the modular spatial model and projected onto the Perspective Plane. Exterior and interior views can therefore be constructed from measurable Object-Space information.
The underlying principle is one of spatial correspondence: a point possessing a defined location in the three-dimensional model must possess a corresponding projected location within the perspective image.
Inverse Modular Perspective
A particularly powerful feature of the system is that the relationship can also be examined in reverse.
If sufficient geometrical information is available within an existing perspective image, Modular Perspective can be used to investigate the Object-Space geometry from which the image could have been formed.
This can allow an investigator to estimate or reconstruct:
- spatial dimensions;
- object size;
- relative position;
- depth;
- the position of the observer;
- the geometry of architectural space; and
- relationships between repeated spatial modules.
Modular Perspective therefore connects perspective construction with the wider problem of inverse perspective: determining spatial causes from their projected image.
Analysis of Perspective Images
García-Salgado has applied Modular Perspective to the geometrical investigation of existing works of art, including paintings by Johannes Vermeer and Leonardo da Vinci.
In such applications, repeated architectural or floor elements can function as modules from which larger spatial relationships are reconstructed. Vanishing relationships, the location of the observer and the dimensions of represented architectural space can then be examined within a common geometrical framework.
This demonstrates that Modular Perspective is not only a method for producing new drawings. It is also a method for analysing the geometrical structure of existing perspective images.
Modular Perspective and Human Vision
García-Salgado relates the geometry of Modular Perspective closely to the spatial structure of seeing. The observer occupies a definite position, and objects located within the observer’s visual field possess measurable spatial relationships that determine their projection onto the Perspective Plane.
From this standpoint, perspective is not simply an arbitrary artistic convention. It establishes a geometrical model relating observer position, object position, direction, distance and projected Form.
This geometrical model should nevertheless be distinguished from the complete biological and perceptual processes of human vision. Human Visual Perspective involves binocular, optical, retinal, physiological and perceptual processes beyond the geometrical projection described by a graphical perspective system.
Modular Perspective and Linear Perspective
Modular Perspective belongs to the wider family of geometrical and graphical perspective methods and retains the projective relationships associated with central perspective.
Its importance lies not in rejecting the geometry of Linear Perspective but in providing a different working model and method of construction. The modular coordinate framework makes spatial position and dimension accessible directly within the perspective system and allows operations that can be cumbersome when undertaken through conventional plan-and-elevation constructions.
Modular Perspective is therefore better understood as a distinctive geometrical method of perspective rather than as a separate optical law governing image formation.
Modular Perspective and Computer Graphics
García-Salgado developed his work during a period in which computer graphics increasingly replaced manual geometrical construction for many architectural applications. His approach does not depend upon rejecting digital methods.
Instead, Modular Perspective demonstrates the continuing value of understanding the underlying three-dimensional geometry of perspective. A computer can calculate and render a perspective image rapidly, but geometrical understanding remains important when a designer or researcher needs to reason about viewpoint, spatial correspondence, dimensions, reconstruction or the causes of a particular perspective appearance.
Principal Applications of Modular Perspective
The method has a range of potential applications:
- Architectural perspective — construction of interior and exterior perspective views;
- Architectural design — designing and judging spatial Forms directly within perspective;
- Measured drawing — relating three-dimensional dimensions to perspective images;
- Image reconstruction — recovering spatial information from existing perspective views;
- Perspective analysis — examining the geometry of photographs, drawings and paintings;
- Art-historical analysis — investigating the spatial construction of historical perspective images; and
- Perspective education — developing understanding of the relationship between three-dimensional space and projected image geometry.
Two Meanings of Modular Perspective
The Dictionary of Perspective distinguishes García-Salgado’s Modular Perspective from a more general use of the term Modular / Brick Perspective.
Modular / Brick Perspective can refer generally to graphical methods in which objects or scenes are divided into regular geometrical blocks or modules so that their dimensions and perspective distortions can be constructed more easily.
García-Salgado’s Modular Perspective, by contrast, is a specific developed geometrical method based upon its own spatial model of symmetry planes, modular coordinates and a Perspective Plane.
The two ideas are related through their use of modular spatial organisation but should not be treated as identical methods.
Why Modular Perspective Matters
Modular Perspective is important because it demonstrates that geometrical perspective remains capable of development beyond the historical construction methods normally associated with Renaissance Linear Perspective.
By connecting spatial coordinates, perspective projection, measurement and inverse reconstruction within a common geometrical model, García-Salgado’s method turns the perspective image into something more than a visual representation. It becomes a measurable spatial system in which three-dimensional relationships can be constructed, analysed and recovered.
It consequently provides an important modern example of perspective functioning simultaneously as a method of drawing, design, measurement, spatial analysis and geometrical reasoning.
Tomás García-Salgado Resources
Further information about Modular Perspective and García-Salgado’s research can be found through his official websites:
His publications on the subject include works on Perspectiva Modular, Modular Perspective for architects, architectural design applications and geometrical analyses of historical perspective images.
Related Perspective Topics
- Linear Perspective →
- Perspective Method →
- Graphical Perspective →
- Object Space →
- Image Space →
- Inverse Perspective →
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Further reference:
Dictionary of Perspective ·
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