2.4 Digitize Polygon
Level of expertise required for this Chapter: Beginner; general Map Maker training
1. The standard process to digitize a new polygon (for example, land use, parcel, administrative unit) starts from the toolbar left:
Alternatively, you can call the polygon digitizing mode through Main menu > Tools > Drawing > Polygon.
2. You then define the outline of the polygon by clicking all ‘corners’ of the polygon with the left-mouse. The polygon does not have to be ‘closed’: Just finish it by right-click.
A Polygon window will appear, where you can enter the characteristics: In most numeric cases this will be the Style number. According to the type of map you digitize (Local plan, Structure Plan, land use map etc), at the first polygon you should change the style definitions (classification) by Polygons window: Styles > Edit project style set >
> Style set editor window: Style management > Import style set and overwrite >
> Choose style set window: Select the classification of your current map (see also Annex 6) > OK > OK > OK
If you want to enter a text label, like a name, use the Display Label (under tab Basics).
Note: You can determine, which tab of this window will pop up through Main menu > Edit > Live layer options > New object options > Show parameters dialogue box on creation.
After having entered the polygons, do not forget to save this live layer: Right-mouse > Save live layer as… > Select folder > Specify file name
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2.4.2 Entry of Defined Shapes
You can also draw precise circles or rectangles: Right-mouse > Drawing > Circle (or Rectangle).
If it will be a circle, you define the centre point and the radius (in meters). If it is a rectangle, you define the two opposite corners.
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2.4.3 Fuzzy Entry
If you are a planner and are not interested in the accurate shape and position of the polygon at this stage, you might want to alter the shape in a fuzzy way.
You can do so with the Edit-tool: Edit (at the toolbar left) > double-click on the new polygon,
Icon at the bottom right ('Drag object') lets you move the polygon:
Icon at the top left ('Revolve object') lets you rotate the polygon:
Icons at the bottom left or top right ('Stretch') lets you stretch the polygon:
Clicking on individual vertex points (red points) lets you edit the shape of the polygon
For a planner, it might be important, to know the area size of the new polygon already in this stage:
You can set this by Main menu > Edit > Live layer options > Live layer label options > Live layer labels window: Area > OK
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More specific polygon entry modes are described at following Chapters.
An interesting alternative, specific for entry of field survey with conventional methods, is explained in Annex 16.