Comparing and Inverting Egocentric and Exocentric Perspectives and Panoramas
Introduction:
We view the world from an egocentric point of view (from within looking out), but mirrors and cameras often look at the world from an exocentric point of view (from outside, looking in). For example, movies are usually shot from an exocentric point of view, but occassionally use egocentric views (from a character/monster’s eyes) for a specific effect. But some computer games, and videoconferencing is interesting because it is not only showing a person a different perspective of themselves (or a representation of themselves), but you are also changing their view from ego to exocentric.
If you want to record a panorama, there is a similar difference between using a series of cameras (or series of shots) in one point looking out (lets call it an egocentric panorama) vs having a series of cameras spread around a space looking in at a single object (lets call it an exocentric panorama?). The egocentric panorama is best for recording environments, the exocentric panorama is best for recording objects (which can include people).
I am facinated at how the human brain is so adaptable, that it can quickly adapt to changes in both perspective and centricity so that people can quickly begin to operate or navigate themselves based on what can often be quite complex spatial translations. Examples are everywhere: grasping grey hairs while looking in a mirror, and controlling a fighting computer character as the camera moves around it. The brain can also adapt to a huge variety of other input data including ultrasound and foreign electrical impulses, but that is another tpoic for another time.
Similarly, you can invert both ego- and exo-centric panoramas to get something that approximates the other - while this initially makes your brain spin, you can quickly adapt and relate to this imagery. Below I’ll describe two examples - one inverting in each direction.
Example - Inverting EgoCentric into Exocentric:
I've had the opportunity to play with a Global Imagination Sphere - it is a spherical projector screen (viewed from outside the sphere) designed to show exocentric views of things like planets and eyeballs. But you can also display an egocentric panorama on this exocentric display device - the best way I can think of describing this is its like a 'crystal ball'.
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An egocentric panorama of the inside of a church. Move the mouse over the image above to move the panorama.
The same egocentric panorama, inverted to be played on an exocentric display device.
Example - Inverting Exocentric into EgoCentric:
In 2005 I did some visualisation for the Wizard of Christchurch. The Wizard is a Christchurch celebrity and icon, who is proposing construction of a complex and innovative multimedia experience in Christchurch. The InnerSpace Probe is to be a spherical room, on the inside walls of which is projected an inverted universe. Due to the complex nature of this proposal, I created a 3D model and animation to illustrate the concept.
Now the Earth covers the outer sphere of the universe, and the closer you get to the centre of the sphere, the further out into the universe you go. The Wizard describes more of his philosophies on his site. Doing this helped me make a couple of other interesting observations. In order to visualise it effectively, space had to become non-linear, so that the closer you get to the centre of the sphere, the more compressed distance becomes. Incidentally, this makes the debate as to what is at the new centre of the universe quite interesting... Also, the surface of the Earth is not really the outer edge of the universe - beyond that is the ‘centre’ of the Earth, which streches out to infinity thanks to non-linearaity again - the further from the centre of the sphere, the more expanded distance becomes. Anyway, I digress...
If we compare this to the previous example, then looking at the earth (on the Global Imagination Sphere) would be traditionally exocentric. But after inverting it, we are now inside looking out, which is egocentric. However, it could also be argued that if we are on the surface of the Earth looking out at the universe, then our traditional view is egocentric. Then, when inverted, if we are still on the surface of the Earth, we are looking in towards the universe, which is kind of exocentric (actually I’m not actually sure if this is exocentric because still kind of looking out, just with a more limited field of view). So why the confusion? Well, partly because the interpretation depends on the perspective - whether we are on Earth or looking down at Earth.
