Amogh N P
✦ In loving memory of Amogh N P — Architect · Designer · Visionary ✦
An Indian student constructing an isometric drawing of a building.
Lesson V25ARS123 · Architectural Graphics I

Pictorial Views

One drawing that shows three dimensions — constructed, not sketched.

≈ 35 min

A pictorial view shows three faces of an object in a single picture — the quickest way to make a drawing read as three-dimensional. Here we construct them with instruments: isometric, axonometric and oblique — the precise counterpart to the freehand paraline of Design Drawing.

Learning objectives

By the end of this lesson, you will be able to — mapped to the course outcomes for Building Materials & Construction I:

1
CO5 · Understand

Explain isometric projection and the isometric scale (0.816).

2
CO5 · Understand

Distinguish isometric, dimetric and trimetric — and plan-oblique.

3
CO5 · Apply

Construct cavalier and cabinet oblique views.

4
CO5 · Apply

Build an isometric from the orthographic views.

The pictorial systems

Isometric, axonometric, oblique

Three related systems, each with its own rule — and one number (0.816) that everyone muddles. Select a topic.

Isometric & the 0.816 scale

Three axes at 120°, equally foreshortened. The catch most muddle: a true isometric PROJECTION foreshortens lengths to 0.816 (the isometric scale); an isometric DRAWING just uses full true lengths for convenience and is therefore about 22% larger. Same shape — only the size differs.[1]

Isometric — three axes, one scale 120° all three faces, equally foreshortened Axes at 120°. True isometric PROJECTION foreshortens lengths to 0.816; an isometric DRAWING uses full lengths (≈22% larger) for convenience.
DiagramThe isometric axes at 120 degrees and the isometric scale of 0.816
The axonometric family IsometricDimetricTrimetric 3 equal angles2 equalall 3 different "Axonometric" = measured along the axes. Plan-oblique (planometric) keeps the plan TRUE and raises verticals — architects' favourite.
DiagramThe axonometric family: isometric, dimetric and trimetric
Oblique — the front face stays true Cavalier — full depth true, but looks too deep Cabinet — half depth depth halved — looks natural
DiagramCavalier oblique with full depth versus cabinet oblique with half depth
Constructed, not guessed

Build it from the views

A constructed pictorial is taken straight from the orthographic views — heights, widths and depths stepped off along the three isometric axes.[1]

From flat views to a constructed isometric frontplanside measurements stepped along the iso axes Heights, widths and depths are taken straight from the orthographic views and stepped off along the three isometric axes.
DiagramBuilding a constructed isometric from the orthographic views
A clean isometric line drawing pinned on a drawing board.
PhotoA clean isometric line drawing pinned on a drawing board.
A planometric axonometric line drawing of a small building.
PhotoA planometric axonometric line drawing of a small building.
A cabinet-oblique drawing with the front face true and depth halved.
PhotoA cabinet-oblique drawing with the front face true and depth halved.
An Indian student constructing an isometric drawing of a building.
PhotoAn Indian student constructing an isometric drawing of a building.
Farish to the moderns

Where it came from

William Farish formalised isometric drawing in 1822; Auguste Choisy turned the worm's-eye axonometric into a tool of architectural history; and De Stijl, the Bauhaus and El Lissitzky made axonometry a signature of modernism.[4]

Check your understanding

Self-assessment

1. The isometric scale (~0.816) belongs to:

2. In a plan-oblique (planometric) view, what stays true shape?

3. Cabinet oblique differs from cavalier oblique by:

In a nutshell

Recap

Isometric: axes at 120°; projection foreshortens to 0.816, drawing uses full length (~22% larger).
Axonometric family = isometric / dimetric / trimetric; plan-oblique keeps the plan true.
Oblique keeps the front true; cavalier = full depth, cabinet = half depth (more natural).
Construct pictorials from the orthographic views — Farish formalised isometric in 1822.
The evidence

References & further reading

  1. [1]Isometric projection — axes at 120°, the isometric scale 0.816 vs full-length isometric drawing. https://en.wikipedia.org/wiki/Isometric_projection
  2. [2]Axonometric projection — isometric / dimetric / trimetric; history (Farish 1822, the moderns). https://en.wikipedia.org/wiki/Axonometric_projection
  3. [3]Oblique projection — cavalier vs cabinet; plan-oblique / military projection. https://en.wikipedia.org/wiki/Oblique_projection
  4. [4]William Farish, 'On Isometrical Perspective' (1822) — the rules of isometric drawing. https://en.wikipedia.org/wiki/William_Farish_(chemist)

Further reading

  • Ching, F.D.K. (2023). Architectural Graphics (7th ed.). Hoboken, NJ: Wiley — paraline and pictorial drawing.
  • Bhatt, N.D. (2014). Engineering Drawing — Plane and Solid Geometry (53rd ed.). Anand: Charotar — Isometric Projection.

Sources gathered and fact-checked June 2026. Published values vary by source, sample and method — treat as indicative and confirm against the cited standard before structural use.

Architectural Design I — StudioPut every drawing type to work designing and presenting a scheme.