Perspective Process

LEVEL 1 — PHYSICAL AND MODELLED FORM

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LEVEL 2 — APPARENT FORM

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A Perspective Process is the operation through which a spatial object, scene, image or view is viewed, formed, imaged, captured, calculated, projected, measured, transformed, represented, simulated, displayed or interpreted.

Within Perspective Category Theory (PCT), the Perspective Process is the active operation linking a spatial source or target with the image, view, representation, measurement, model or spatial appearance that results from it.

In simplified form:

Object or Target Space → Perspective Process → Image or Perspective Space → Outcome or Product

The concept is fundamental because perspective is not merely an image or visual appearance. It also comprises the processes through which spatial information is acquired, transformed and presented.

Perspective Process within Perspective Category Theory

Perspective Category Theory distinguishes several different properties of a perspective operation.

Perspective Category identifies the principal source or mode of the process;
Perspective Class identifies the principal direction in which it operates;
Perspective Type identifies the particular method, system, process or subdivision involved;
Perspective Form identifies the visual, optical, geometrical or spatial appearance produced;
Perspective Goal or Function identifies what the process is intended to accomplish;
Perspective Product or Outcome identifies what the process produces.

The Perspective Process lies at the centre of these relationships because it is the operation through which perspective actually occurs.

From Object Space to Image Space

A Perspective Process normally operates upon an object, scene, image or spatial relation located within Object Space or Target Space.

The process then forms, transforms or presents corresponding spatial information within Image Space or Perspective Space.

The general relationship is:

Object or Target Space → Perspective Process → Image or Perspective Space

The resulting image does not necessarily duplicate the original space. Some spatial properties may be preserved while others are reduced, compressed, concealed, distorted or otherwise transformed.

Perspective therefore involves both spatial correspondence and spatial transformation.

What can a Perspective Process do?

The Dictionary definition encompasses a wide range of operations.

A Perspective Process may:

view a spatial object or scene;
form a visual or optical image;
capture or record an image;
calculate spatial or projective relationships;
project light, images, lines or spatial information;
measure spatial relationships;
transform spatial or image information;
represent an object or scene;
simulate a selected spatial appearance;
display an image or model; or
interpret a resulting view or spatial relation.

A complex perspective system may perform several of these operations rather than only one.

Natural Perspective Processes

Perspective Processes may be natural or artificial.

Natural Perspective Processes arise from spatial relationships and naturally occurring optical or visual conditions.

They may involve:

the physical organisation of objects and scenes;
relative spatial position;
distance;
orientation;
light;
shadow;
reflection;
refraction;
atmospheric conditions; and
natural visual appearance.

Such processes do not require a human-made graphical construction, instrument or computational system in order to exist.

Artificial Perspective Processes

Artificial Perspective Processes involve deliberately constructed, calculated, captured, projected, simulated or represented images and views.

They may employ:

Mathematical Perspective;
Graphical Perspective;
Optical Perspective;
Instrument Perspective;
Simulated Perspective; or
New Media Perspective.

Examples include constructing a Linear Perspective drawing, photographing a scene, projecting an image, creating a Forced Perspective environment or generating a computer-rendered perspective view.

Natural and artificial therefore describe broad modes of operation; they should not be confused with the two fundamental directional Perspective Classes.

Optical Perspective Processes

An Optical Perspective Process uses, or purports to use, light or other electromagnetic radiation to form, capture, present or project views and images of spatial objects and scenes.

Such processes may involve:

visible light;
infrared radiation;
ultraviolet radiation;
X-rays;
gamma rays;
microwaves; or
radio waves.

The relevant rays may be real, imagined or simulated according to the process or model under consideration.

Optical Perspective therefore extends considerably beyond ordinary unaided human vision.

The Viewing or Imaging Process

Within the Viewing or Imaging Class, a Perspective Process operates principally in the image-forming or capturing direction.

Light, visual information or spatial data passes from an object, scene or existing image towards an eye, sensor, image plane or imaging system.

The directional relationship can be represented as:

object or scene → eye, sensor or imaging system

A view, image, measurement or representation may then be formed, captured, presented or perceived.

Examples include natural vision, camera imaging, microscopy, telescopic viewing and sensor-based imaging.

The Projecting Process

Within the Projecting Class, the Perspective Process operates principally in the forward or image-projecting direction.

Light, images, shadows, lines or spatial information are projected from a source or representational system into physical, graphical, optical or simulated space.

The directional relationship can be represented as:

source or representational system → projected image or spatial information

Examples include cinema projection, graphical projection, shadow formation, projected displays and other systems that project visual or spatial information forwards.

Perspective Process and Perspective Class

A Perspective Process should not be confused with a Perspective Class.

The Process describes the operation taking place.

The Class describes the principal direction in which that operation proceeds.

Thus:

Perspective Process → what operation occurs
Perspective Class → in what principal direction it operates

The same broad kind of process may operate differently according to its directional organisation.

Some systems may also employ both classes sequentially or together.

Perspective Process and Perspective Category

A Perspective Category identifies the principal source or mode through which a Perspective Process operates.

The principal categories are Natural, Visual, Optical, Mathematical, Graphical, Instrument, Simulated and New Media Perspective.

The distinction can therefore be stated as:

Category = source or mode of the process
Process = operation being performed

A photographic process, for example, may involve Optical and Instrument Perspective, while a computer-generated process may involve Mathematical, Graphical and New Media Perspective.

The process and its categorical classification therefore provide complementary information.

Perspective Process and Perspective Method

A Perspective Method and a Perspective Process are closely related but analytically distinct.

A Perspective Method describes the organised procedure, principles or means used to achieve a particular perspective operation.

The Perspective Process is the operation that occurs when those principles or methods are applied.

In simplified terms:

Method → procedure or means
Process → operation

For example, a graphical construction method may prescribe how projection lines, vanishing points and a picture plane are used. Carrying out that procedure constitutes the perspective process through which the resulting image is constructed.

Perspective Process and Perspective System

A Perspective System may contain one or more Perspective Processes organised into a larger working arrangement.

A camera system, for example, can include:

light entering from Object Space;
optical image formation;
image capture by a sensor;
electronic processing;
storage; and
subsequent display.

Each can be considered a process or stage within the larger system.

A Perspective System may therefore contain a sequence or network of Perspective Processes rather than constituting only one isolated operation.

Perspective Process and Perspective Type

A Perspective Type is a particular method, system, process or subdivision within one or more Perspective Categories.

Perspective Type therefore identifies what particular kind of perspective is involved, while Perspective Process emphasises what operation is taking place.

For example, Linear, Spherical, Anamorphic, Stereoscopic, Panoramic and Forced Perspective may each involve particular processes.

A Type may be defined through its geometry, optics, viewpoint structure, image surface, instrument, medium, spatial effect or use.

The process describes the actual formation, calculation, projection, transformation or representation through which that Type operates.

Perspective Process and Perspective Form

The Perspective Process should also be separated from the Perspective Form it produces.

A Perspective Process is an operation.

A Perspective Form is the resulting visual, optical, geometrical or spatial appearance.

Thus:

Perspective Process → operation
Perspective Form → resulting appearance

A perspective process may produce changes in apparent size, shape, orientation, position, line convergence, colour, clarity, contrast, curvature, depth or other characteristics of the resulting image or view.

Confusing the process with the appearance it produces is one of the major sources of ambiguity in perspective terminology.

Perspective Process and Perspective Product

A Perspective Product is the outcome produced by a Perspective Process.

Possible products include:

a visual image;
a view;
a measurement;
a calculation;
a representation;
a model; or
a spatial appearance.

The relationship can therefore be represented as:

Perspective Process → Perspective Product

The distinction is fundamental: the process is what occurs, while the product is what results.

Goals and Functions of a Perspective Process

A Perspective Process may be undertaken for many different purposes.

The principal Goals of Perspective include:

viewing;
imaging;
projecting;
measuring;
matching;
representing;
creating illusion; and
producing immersion.

Related functions include capturing, observing, calculating, classifying, modelling, surveying, mapping, indexing, gauging, linking, mixing, exploring and displaying.

These goals and functions should not be confused with Perspective Categories or Classes. They describe what the Perspective Process is intended to accomplish.

Contact Perspective Processes

Not every Perspective Process operates through distant optical viewing.

The Dictionary identifies a Contact Perspective Process in which a spatial object or scene is surveyed through direct physical contact or material sensing.

Examples can include processes related to:

moulding;
casting; and
other direct-contact means of recording or obtaining information about spatial Form.

This broadens the concept of perspective beyond the assumption that every perspective relationship must arise solely through visible rays travelling from a distant object to an eye or camera.

Several Processes can operate in sequence

A modern perspective image is frequently the product of several Perspective Processes operating successively.

For example:

Natural scene → Optical and Instrument imaging → New Media processing → display → human viewing

The initial spatial scene, camera, digital processing system, display and human visual system participate at different stages.

This means that the final image should not necessarily be attributed to one isolated process.

Its appearance may reflect a complete chain of Perspective Processes.

Perspective Process and Category Chaining

When several Perspective Categories operate sequentially within an image or perspective process, the relationship is described as Category Chaining.

A typical sequence might be:

Natural → Optical and Instrument → New Media → Visual Perspective Type 2

Different Perspective Processes therefore may succeed one another as spatial information moves through the complete image chain.

The resulting system or image may constitute Composite Perspective.

A Process may belong to more than one Category

A single Perspective Process may also legitimately belong to more than one Perspective Category.

This relationship is called Category Overloading.

Linear Perspective provides an important example. A Linear Perspective process may be Mathematical because it depends upon geometrical relationships and Graphical when those relationships are used to construct a drawing.

A digitally rendered Linear Perspective process may additionally involve New Media Perspective.

The existence of several categorical classifications therefore does not necessarily mean that several independent processes are involved. Sometimes one process itself crosses categorical boundaries.

The Perspective Process can transform spatial information

A Perspective Process may substantially transform the spatial information passing through it.

Depending upon the process, transformations may affect:

apparent size;
shape;
orientation;
position;
scale;
depth;
line direction;
colour;
clarity;
contrast;
visibility; or
spatial continuity.

The final image or view therefore arises partly from the original Object Space and partly from the particular Perspective Process through which that space is viewed, measured, calculated, imaged or represented.

Process and Outcome must be distinguished

Perspective terminology frequently uses the same expression both for a process and for the image or appearance produced by that process.

This can create Categorical Ambiguity.

For example, the term Linear Perspective may refer to a mathematical or graphical method and process, but it may also be used for the geometrical appearance produced by that process.

Perspective Category Theory therefore distinguishes:

Method or Process → how the perspective is produced
Outcome or Form → what appearance or image results

This distinction is essential for clear perspective terminology.

Why Perspective Process matters

The concept of Perspective Process shifts attention from the final image alone to the operations through which that image or view is produced.

It makes it possible to ask:

What spatial object, scene, image or view is being acted upon?
What operation is taking place?
Which Perspective Category or Categories are involved?
In which Perspective Class or direction does the process operate?
Which Method or Type is being used?
How is the spatial information transformed?
What Goal or Function is being pursued?
What Perspective Form appears?
What Product or Outcome results?

Perspective Process is therefore a foundational concept within Perspective Category Theory because it identifies the operation through which principles or methods form, capture, calculate, project, represent, simulate, display or interpret a view, image or spatial relation.