File:Geometric enhancements.JPG

English: The process of representing a graphic object in virtual space allows a number of different opportunities to introduce informative geometric distortions or enhancements. These either may be a modification of the transforming matrix during the process of object definition or may be modifications of an element of a model. These modifications may take place

(1) in an object relative coordinate system used to define the object's shape, or

(2) in an affine or even curvilinear object shape transformation, or

(3) during the placement transformation that positions the transformed object in world coordinates, or

(4) in the viewing transformation or

(5) in the final viewport transformation.

The perceptual consequences of informative distortions are different depending on where they are introduced. For example, object transformations will not impair perceived positional stability of objects displayed in a head-mounted format, whereas changes of the viewing transformation, such as magnification, will. (Source: Stephen R. Ellis (1996). "Virtual Environments and Environmental Instruments".)