Building of surface by isolines

The surface built by isolines, finally represents the regular array of elementary parts of heights or given qualities of terrain obtained by conversion of the initial vector data of region into raster image.

The element of a surface site corresponds to a square site of terrain, the size of the side which is named as accuracy of a matrix. At building of surface the map objects having the characteristics "true altitude" are selected.

The surface, appropriate to the vector model in the form of isolines, can be built by method of a stepwise contouring, as a result of which there are new contours on boundary of contours of filling areas, the new contours are allocated in the middle of old contours, i.e. the linear interpolation of height is executed. With each stage of a contouring the quantity of isoline contours is doubled. So lasts so long as the contours will not be closed.

Input data for building of surface by isolines are the marked map objects or objects marked with the help of "Filter" button. Quantity of marked objects on all map is calculated and is shown into "Is allocated" window. In "Is processed" window the quantity of marked objects in selected area is placed. Objects semantics for building of surface is always TRUE ALTITUDE.

The result of surface building is saved in a matrix map. Name of output file is set automatically and consists of a map filename with addition of "*.mtw" or "*.mtq" extension. The filename can be changed by user, for this purpose it is necessary in an edit window of matrix name to select a name of matrix. If matrix of qualities (*.mtq) was selected, Palette button becomes active. At pressing onto Palette button it is possible to set colors amount of imaging and their gradation in the given range. By default palette of qualities matrix is black-and-white.

Accuracy of matrix is indicated in meters in Diskret window. Quantity of lines and columns of matrix is calculated and varies depending on selected area of surface creation.

Area of a surface creation by isolines can be:

- all area occupied by the initial map;

- rectangular fragment.

For building surface onto all area it is necessary to click All region button.

For building surface onto given fragment of terrain it is necessary to click Select button, then by two left mouse button clicks to select a fragment of terrain on the map. The coordinates of a selected fragment are displayed in Coordinates matrix window. By default creation of a surface by isolines will go onto all area defined by map.