TECHNIQUES OF PANORAMIC MAP-PICTURE CREATION ON THE BASE OF THE LOCALITY
PERSPECTIVE DRAWING
R.V.Atojan
Kvadrograf Publishing House
rubyan@yandex.ru
Cartographic activity provides constant search for new ways of the reality objects modelling, containing the most informative and evident techniques. The perspective picture possesses the specified qualities. Being one of the most ancient ways of representation the locality objects, it now has gained new development at creation of tourist thematic maps. In scientific aspect the following directions of studying and evolution of a perspective drawing are of interest:
— Development of
theoretical basis of a prospect;
— Research of
object perception in three-dimensional space;
— Automation of
the prospect construction ways.
Each of the specified themes makes extensive exploratory work that is impossible to embrace even in a general way in one paper. Therefore here we shall emphasize only on consideration of the graphical methods used at construction of the prospect of a locality section where is important to truthfully transfer depth of the image. Imitation of the image depth is attained by means of colour effects and graphical techniques. First thus use «principles of an air- and colour prospect», second — visual codes of depth.
«The principle of the air prospect» is based on a vital habit to see in the nature a change of colour in process of moving off objects. Visual codes of depth make a complex of the graphical techniques used in aggregate at construction of stereoscopic pictures. The essence of visual codes of depth consists in the following:
1) in process of
moving off the point of observation, the ratio of magnitudes of the same
subjects is in inverse proportion to distance;
2) a section of
locality (or the subject) of the right-angled shape in space is represented by
a trapeze;
3) perceived
partial overlapping of subjects bears the information on their relative
remoteness;
4) with increase
of the observation distance the density of the projective image increases.
Codes accordingly refer to: Relative magnitude, linear prospect, interposition, a density gradient.
At construction of a prospect there is a necessity of generalization the images of objects depending on scale. On perspective maps the variable scale occurs. Diversity of the image is transferred in a picture plane with application of visual codes of depth. Using graduations of light exposure and a rule of shadow construction, it is possible to achieve expressive and volumetric picture.
Formulation of perspective is a complex process which can be executed by cartographers-designers of high qualification. All process conditionally shares on following stages: Sampling of a projection direction, definition of horizon altitude, image depth, and type of a projection and construction of the image on a maps-basis.
Use of modern technical means allows in the interactive regime on a digital model of locality to define parameters of the prospect, to carry out gathering and ordering of used materials on digital carrier, operatively and with high quality to prepare a product for the publication.
The perspective drawing opens really ample opportunities at creation of tourist maps. Before other aspects of the image, the prospect has following advantages: Presentability and accessibility of perception.