Forced perspective

Forced perspective is "a technique that employs optical illusion to make an object appear farther away, closer", larger or smaller than it is (Wikipedia: Forced perspective).

It is the deliberate version of the scale cheating described on scale and proportion.

#How it works

Distance and size trade against each other. An object twice as far away looks half as big, so a small object close to the viewer can look like a large one far away. Designers use this in two ways:

• Shrink details with height or distance so an object reads as taller or deeper than it is.
• Place objects at different depths so they look side by side at different sizes.

Both only hold from the intended viewpoint. Wikipedia: "If the camera's point of view were moved, then parallax would reveal the true relative positions" (Wikipedia: Forced perspective). And angular size alone "cannot fully trick the eye": aerial perspective, lighting and blur must also agree (Wikipedia: Forced perspective). See fog and atmosphere.

#Theme parks and film

#Forced perspective in games

Players control the camera, so forced perspective in games is mostly used where the player cannot go: backgrounds, skyboxes and fixed views.

#Using it in your own levels

• Skyline buildings: smaller windows and floors near the top make a backdrop building feel taller, as with the Disney castles (Wikipedia: Forced perspective).
• Unreachable vistas: build distant scenery smaller and closer, as Source's 3D skybox does, but keep real parallax (Valve Developer Community: 3D Skybox). See sightlines and vistas.

#Related pages

scale and proportion · sightlines and vistas · landmarks · fog and atmosphere · sky, clouds and volumetrics · impostors and billboards · cameras, lenses and field of view · field of view

#Further reading and watching