The web campaign for the sporting goods manufacturer is considered the starting point for a web design trend, which makes use of the parallax scrolling effect to produce an illusion of depth.
Similar to side-scrolling games, parallax websites also use the so-called layer method: the starting point is a single page website where design elements are arranged on different levels and can be moved independently in a horizontal or vertical direction.
In order to trigger the motion-induced depth perception, the website visitor has to navigate through the scenery with the scroll function. The movement and speed of the image are not fixed but are controlled by the viewer when they scroll with the mouse or the sidebar. Elements on the foreground layers move faster across the screen than elements on the background layers. This gives the impression of it being in 3D.
In a few cases, parallax websites also have an auto-scrolling feature, which means the visitor doesn’t have to scroll as much manually. In order to achieve a stronger sense of immersion, some web developers also use sound and video effects alongside parallax scrolling, which comes into effect when the viewer is at a certain place on the website.