Illustrations: External perspective

From TechWriter Wiki

A perspective illustration is one that provides a view of an object from a 'realistic' viewpoint - that is, a close approximation to how the actual object would appear when viewed in real life. An external perspective shows the true view of the object. Compare this with a cut-away illustration.

Example: An illustration of an engine, shown in perspective

Perspective illustrations provide a complete visual representation of the object being illustrated. They are therefore extremely useful where the reader of the document (the person viewing the illustration) does not necessarily have the actual physical object to hand - for example, in sales literature.

Perspective illustrations may also be useful for identifying the location of external fixtures on an object - for example, the location of the service access points on a vehicle, or the places where safety notices should be (or have been) placed.