This paper explores the visual phenomena of a seeming change of the target-object's size (as a focus of concrete visual perception) in the function of an observer's motion so that it 'seems' contrary to the law of linear perspective (in the sense of an expected increase of the target volume/monumentality - by getting closer or a decrease - by getting farther away). This phenomenon is described in a geometrical and perceptual aspect; the result of this comprehensive approach led to identify parameters that determine it phenomenologically. It was established that the explored visual phenomenon is a specific 'size illusion', i.e. an 'angular size illusion' that occurs when influenced by factors of the perceptual kind - activated by a specific dynamic relationship (on a visual plan) between the target object and its surrounding competitive objects, as an observer moves. By understanding the character of this phenomenon (both in a geometrical and perceptual sense), it is possible to apply the acquired knowledge in practice - in programming the visual effects to be obtained (such as to visually optimize or minimize the monumentality of targeted objects) in all architectural and urban fields (planning, designing and reconstruction)

This paper investigates the impact of various extrinsic shooting parameters regarding change of roughness-quality of surface textures of linear objects/elements when presented in the form of unstructured photogrammetrially created point-clouds. To perfom this scientifically-wise, two types of specific quality-descriptors are identified: process-quality descriptors and smoothness related quality descriptors. Then, they are precisely defined, computed and mutually correlated. It can be generally concluded that for a fixed focal length, shooting directions perpendicular to the axis of targeted object/element, stationpoints uniformly radially distributed around it (at a circle of 360 deg.) and obtained process-quality descriptors values that belong to satisfying /recommended ranges, the performed photogrammetric digitalization is declared highly precise and satisfyingly accurate regarding roughness /smoothness and barely prone to object-to-camera distance.