Changing the parameters of the TIN model

The parameters of the TIN model can be edited in the TIN Legend Editor (Figure 8.4) window that appears after a double left click on the name of the model (can be seen on top of the theme list in Figure 8.3). The elements of the Legend Editor are the following:

• Theme: theme on which the elevation model is based

• Points window part: for setting the point objects

• Lines window part: for setting the line objects

• Faces window part (surface): for setting the filling of the surface

Figure 8.4: Parameters of the elevation model 7.1.2.1. Lines window part

In the Lines menu item the contour lines that give the basis for the elevation model can be displayed the parameters of the contours can be given in the pop-up window (Figure 8.5) appearing after clicking on the Edit button found in this window part.

Figure 8.5: Setting the contour lines of the elevation model Parts and settings of the Legend Editor window:

• Theme: theme on which the elevation model is based - should remain unchanged.

• Legend Type: category type of lines can be given. In the present case this can be only Unique Value (nothing else is offered).

• Values Field: Breaklines setup should remain unchanged.

• Symbol - Value - Label show the actual settings of the category, the Count show the number of elements in the given category.

• Color Schemes: predefined colour distribution according to the character of the content.

For more detailed discussion of the display see chapter 12 of the Geoinformatic Applications textbook. In case we would like to display the contour lines differently (basic, main and subsidiary contours) this option has to be switched off by clicking into the square left of the Lines script. Switched off state is indicated by the disappearing tick. Then drag the theme on which the elevation model is based above the elevation model in the list (otherwise it remains covered) and open it and attribute settings to it (colours, line thickness - for the procedure of this see chapter 12.2 of the Geoinformatic Applications).

7.1.2.2. Faces (surface display) part of the window

The parameters of surface display can be given in the Faces part of the window. Its parts are the following:

• Label: text in the caption of the legend. The Elevation Range text can be rewritten if needed (for example in the case of constructing a Hungarian map it could be rewritten into „Magasság” - as this cannot be changed elsewhere /e.g. when the map is finalized/).

• Legend: colour distribution appropriate for the elevation model can be selected. Possibilities are the following:

•

• Illuminate faces: in switched on state (indicated by a tick in the square left of the script) the surface will be displayed with hillshade, or without it if the function is switched off (Figure 8.6).

Figure 8.6: Relief display without (left) and with (right) relief shadowing

Selecting the Edit… button in the Faces frame the Legend Editor window pops-up (Figure 8.7) the elements of which are the following:

• Theme: layer of the actual TIN model

• Legend Type: type of filling can be determined. In this analysis only the Graduated Color option can be selected.

• Classification field (column of classification): Column of data used for calculating the TIN model.

• Normalyze by: in the case of any calculation only one member of it can be selected

• Below the Symbol - Value - Label captions the current settings of the actual layers can be seen.

• Color Ramps: pre-defined colour distributions according to the character of the content, i.e. palettes can be set here for the determination of the digital height colours. Note that the colour grades generated automatically by the software are not always the same as those applied traditionally in mapping (8.1. animation). The author recommends the Red Monochromatic and the Beige to Brown types. Since the two extreme values of the colour grades are adjusted to the extreme values of the given area it is possible that the - otherwise adequate - green-brown will cause problems as well: because independent from the absolute height above sea level white will be attributed to the highest parts! Therefore people will have the feeling that the highest regions are covered by eternal snow - even if the areas are much lower! (For example in the case of the elevation model of Hungary the highest areas of the Mátra and the Bükk appear in white!) Without the definition of an individual palette - as it is a lengthy process with numerous potential errors - this problem can be solved by a simple solution: set the categories so that no areas are included in the highest one. Considering the Hungarian example this means that the lower boundary of the highest category would be 1015 metres (or a value slightly

above it). Moreover, completely unique colour distribution is also possible, for more details see chapter 12 of Geoinformatic Applications.

Figure 8.7: Automatic setting of the height colouring of the elevation model

8.1. animation: The elevation model with various palettes

When the TIN model is created not only one but eight pieces of adf format file are also created that can be found in a sub-folder within the folder of the work - the name of the sub-folder had to be given in the initial phase of TIN creation (Figure 8.2)