Orthographic projection

Edges of the same direction remain parallel and distant parts do not shrink dramatically.

Visual traits

• Parallel lines
• Stable proportion
• Depth without a vanishing point

Expected changes

• Edges in the same direction are more likely to remain parallel
• Proportion is easier to compare

Definition

It projects objects with parallel viewing rays and retains parallel edges of the same direction. It differs from one-point perspective and isometric projection.

In more detail

It makes form and proportion easier to compare in architectural elevations, product faces, and map-like diagrams. Subject and medium remain separately selectable.

Includes

• Orthogonal projection that preserves parallel lines

Excludes

• Perspective converging to a vanishing point
• Isometric projection
• Lens distortion

What this does not imply

• A particular building
• Isometric projection
• A particular lens

Variability

The shown face such as front, side, or plan can be selected separately.

Usage

• Keep edges of the same direction parallel
• Specify subject and shown face separately

Distinguish similar expressions

• Use one-point perspective when a vanishing point is required

Typical uses

• Compare an architectural elevation
• Show product form without perspective distortion

Possible failure modes

• Lines converging to a vanishing point
• Distant parts shrinking strongly