Where am I? Using Feature Cues for Navigation
The feeling of not knowing where you are is a disturbing but universally known one. Disorientation in a physical spatial environment is something everybody is familiar with. Searching out landmarks, or continuing on, hoping you hit something familiar.
The brain is built to handle such a 3D world, and employs a number of tricks to counter disorientation. These are tricks we can utilise in 3D spatial simulations, to help minimise disorientation there; but first we have to understand what the brain's tricks are, and how they operate.
Previous research has tended to suggest that animals and young children mainly rely on geometric cues such as angles and distances, to aid navigation. But, what about everyone else?
Psychologists Kristin R. Ratliff from the University of Chicago and Nora S. Newcombe from Temple University have conducted a set of experiments which suggest that there is a secondary orientation system, in humans, at least. Feature cues such as colours and textures, if sufficiently different to those in other directions nearby, can be used instead of geometric cues, to orient a person.
This might explain why in virtual environments, when textures are frequently all much of a muchness in any immediate area, there is a pronounced difficulty of navigation compared to physical environments.
The first experiment took place in either a large or small white, rectangular room with a landmark (a big piece of colourful fabric) hanging on one wall. The study volunteers saw the researcher place a set of keys in a box in one of the corners. The volunteers were blindfolded and spun around, to become disoriented. After removing the blindfold, they had to point to the corner where the keys were. After a break, the volunteers were told the experiment would be repeated, although they wouldn't watch the researcher hide the keys.
Whilst the subjects were out of the area on the break, the researchers moved the landmark to an adjacent wall-this change forced the volunteers to use either geometric cues or feature cues, but not both, to reorient themselves and locate the keys. For the second experiment, the researchers used a similar method, except they switched room sizes (the volunteers moved from a larger room to a smaller room and vice versa) during the break.
The results, reported in Psychological Science, a journal of the Association for Psychological Science, reveal that the brain does not have a distinct preference for certain cues during reorientation. In the first experiment, volunteers reoriented themselves by using geometric cues in the smaller room but used feature cues in the larger room. However, the volunteers who went from the larger room to the smaller room in the second experiment also relied on feature cues, searching for the landmark to become reoriented.
Conclusions for Virtual Environments
The conclusions of this study as pertain to virtual environments, are simple. Whilst for memory consumption reasons it is usually better to reuse textures, if you can create a texture or several in any given space that is different enough to the others, to serve as a landmark, it will aid the navigation of those in world, as their brains will recognise it as a landmark, and orient accordingly.
It will not stop all instances of being lost in mazelike warrens of twisty passages, all the same, but it will complement the geometric orientation system, and will help thusly.
This screenshot from the gameworld Fallout 3, shows the type of environment that is bad for this, yet used extensively: Mazes of passageways which are all identically textured, make it very hard to visually orientate yourself, without relying on external maps, or wandering aimlessly.