Level of motion detail in virtual reality.

Current optimizing techniques incorporating the LOD methods in virtual reality are mostly focused on generation of the detail evaluated as the complexity of geometrical representations of models in virtual environment. There are a lot of methods and approaches. These approaches differ in two aspects: the way of detail generation and criteria used to determine which detail should be generated. The first aspect corresponds to the meaning of the term detail itself and its representation. The detail is interpreted as a feature closely connected with the geometrical complexity of an object. Thus the LOD methods usually represent different details by using multiple geometrical representations or these details are produced by a degradation of the single representation. The second aspect is connected with limitations of the human visual system and with precondition that we will not register all details in the scene with the same quality. Thus a lot of criteria were incorporated such as the distance, size, velocity, position in the visual field of the user, or the position against the horopter. In the last years, a phenomenon of the visual perception has influenced development of the LOD methods in such way that these criteria have been derived from the abilities of the real human visual system. Owing to this approach, the perceptually based LOD methods can evaluate the visual conditions of the user automatically without any trial or error estimating methods.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi