Motion parallax
In perception psychology, movement parallax is understood to be the optical effect that results when different objects are distributed in a landscape at different distances from each other and the observer moves laterally parallel to these objects and looks towards the horizon.
principle
The light pattern of nearby objects moves faster over the retina than that of objects further away. This effect occurs, for example, when looking out the side window of a moving car or train.
The result is that those objects that are close to the viewer move faster than those that are far away from the viewer. The movement of the objects approaches zero the closer they are to the horizon, which only moves minimally (depending on the total speed).
However, it is a common misconception that our brain can obtain information about which objects are further away than others from the different speeds of movement of objects across the retina of the eye. From this information can supposedly be obtained, which serve the depth perception. In an experiment, however, Deborah Wheeler and Irvin Rock were able to show that parallaxes of movement are not actually used by the brain for depth perception, although it would be possible in theory.
example
In the picture on the right, the perception of the depth of the room by covering it up helps us to recognize a spatial arrangement. The blades of grass and palm trees cover part of the mountains, which in turn partially cover the moon. However, we cannot say how far apart the objects are from each other, although the different speeds give us an indication of this. But one can say with certainty that the moon is at least the spatial extent of the mountains far from the palm trees. If the moon were so high up in the starry sky that it was not covered by the mountains or the palm trees, we would get the feeling that it could hover somewhere above the mountains and move at the same speed as us. In this case, our experience would simply help us to assess that the moon is normally much further away from us than the mountain range and must therefore be much further away.
Further depth perception features
Further depth perception features of the environment consist in the textures of objects, which appear smaller the further away an object is from the viewer (example: paving stones in a pedestrian zone - the paving stone pattern will appear smaller the further away the street section in question is from the viewer ). "Vanishing points" as they are consciously used in pictures in order to be able to represent plasticity, serve the brain as clues to spatial depth. Modern psychology assumes that complex objects and environmental stimuli are first broken down by the sensory apparatus into individual components of perception and then reassembled into complex sensory perceptions.
history
When at the beginning of the 19th century, in the course of industrialization in western countries, the railroad was so developed that it was available to a broad population, passengers could experience the parallax effect for hours by looking outside. At this point one spoke of the panoramic view .
Motion parallax in video games
The so-called side scroller games and especially the shoot 'em up are of particular importance to the movement parallax . In these games, the player controls a character or a spaceship over a moving background. The parallax effect, in which objects in the foreground move faster than objects in the background, is used to suggest a “deeper” world to the player, but also to provide orientation points.
From a technical point of view, the following four methods are available for this:
Layer method
In this method, the entire view of a series of layers ( narrow. Layers). The foreground, background, and intermediate layers are all designed to move at different speeds.
Fuel method
A collection of images is used for this, which is combined into a pseudo-layer of sprites . If the camera angle is changed, only individual parts of the plane are displayed, creating the parallax effect.
Repeating patterns / animations
The layers consist of individual tiles, the bitmaps of which "float" over a repeating background with the help of an animation.
Grid method
Individual lines of pixels are drawn from top to bottom with a noticeable delay between the lines.
example
The three levels in the animation below move to the left at different speeds. Their speed decreases from front to back, which creates the impression of spatial depth. The ground level moves 8 times faster than the vegetation level, the vegetation level moves twice as fast as the cloud level.
Cloud Plane - Back
Vegetation level - middle
Ground level - front
animation
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Movement parallax in web design
From the end of 2008 onwards, movement parallaxes can be found on websites on the Internet; according to Google Trends , from 2011 onwards with increasing frequency. In 2013, the US company Nike was one of the first large companies to use parallax scrolling. HTML 5 and CSS 3 favor this style.
Motion parallaxes are used on websites to:
- Follow a story-telling approach to guide visitors through the website
- Make page views last longer and encourage the visitor to scroll through all of the page content,
- guide the visitor to calls to action and
- to impress the visitor and to arouse curiosity for further content.
However, the use of movement parallax also creates disadvantages for a website. They arise from the fact that the majority of the websites that use this effect are often single pages , which has a detrimental effect on the SEO and the loading speed of the website.
See also
literature
- E. Bruce Goldstein: Perceptual Psychology . Spektrum Akademischer Verlag, Heidelberg 2002 (2nd German edition) ISBN 3-8274-1083-5
- Irvin Rock: Perception. From visual stimulus to seeing and recognizing. P. 56f. Translated by Jürgen Martin and Ingrid Horn. Spektrum Akademischer Verlag GmbH, Heidelberg 1998. [Orig .: Perception. 1984].
Individual evidence
- ↑ Parralax Effect. In: Programming Shots. July 30, 2017. Retrieved June 17, 2019 (American English).
- ↑ Google Trends on "Parallax Scrolling" ( Memento of the original from March 7, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ t3n on the subject of "Parallax Scrolling"
- ↑ a b What Is Parallax Web Design? - Definitions, Tips & Considerations. August 15, 2013, accessed June 17, 2019 .
