QGIS Training PDF

Foreward: Welcome to our course! We will be showing you how to use QGIS easily and efficiently. If you are new to GIS, we will tell you what you need to get started. If you are an experienced user, you will see how QGIS fulfills all the functions you expect from a GIS program, and more! 1....

Foreward: Welcome to our course! We will be showing you how to use QGIS easily and efficiently. If you are new to GIS, we will tell you what you need to get started. If you are an experienced user, you will see how QGIS fulfills all the functions you expect from a GIS program, and more! 1. Overview 1.1 Why QGIS?  It’s free, as in lunch. Installing and using the QGIS program costs you a grand total of zero money. No initial fee, no recurring fee, nothing.  It’s free, as in liberty. If you need extra functionality in QGIS, you can do more than just hope it will be included in the next release. You can sponsor the development of a feature, or add it yourself if you are familiar with programming.  It’s constantly developing. Because anyone can add new features and improve on existing ones, QGIS never stagnates. The development of a new tool can happen as quickly as you need it to.  Extensive help and documentation is available. If you’re stuck with anything, you can turn to the extensive documentation, your fellow QGIS users, or even the developers.  Cross-platform. QGIS can be installed on MacOS, Windows and Linux. 1.2 Background In 2008 Q GIS launched the Gentle Introduction to GIS, a completely free, open content resource for people who want to learn about GIS without being overloaded with jargon and new terminology. It was sponsored by the South African government. 1.3 An Overview of the Interface This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  1. Layers List / Browser Panel 2. Toolbars 3. Map canvas 4. Status bar 5. Side Toolbar 6. Locator bar The Layers List In the Layers list, you can see a list, at any time, of all the layers available to you. Expanding collapsed items (by clicking the arrow or plus symbol beside them) will provide you with more information on the layer’s current appearance. Hovering over the layer will give you some basic information: layer name, type of geometry, coordinate reference system and the complete path of the location on your device. Right-clicking on a layer will give you a menu with lots of extra options. You will be using some of them before long, so take a look around! The Browser Panel The QGIS Browser is a panel in QGIS that lets you easily navigate in your database. You can have access to common vector files (e.g. ESRI Shapefile or MapInfo files), databases (e.g. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. PostGIS, Oracle, SpatiaLite, GeoPackage or MSSQL Spatial) and WMS/WFS connections. You can also view your GRASS data. If you have saved a project, the Browser Panel will also give you quick access to all the layers stored in the same path of the project file under in the Project Home item. Moreover, you can set one or more folder as Favorites: search under your path and once you have found the folder, right click on it and click on Add as a Favorite. You should then be able to see your folder in the Favorites item. Toolbars Your most often used sets of tools can be turned into toolbars for basic access. For example, the File toolbar allows you to save, load, print, and start a new project. You can easily customize the interface to see only the tools you use most often, adding or removing toolbars as necessary via the View ► Toolbars menu. Even if they are not visible in a toolbar, all of your tools will remain accessible via the menus. For example, if you remove the File toolbar (which contains the Save button), you can still save your map by clicking on the Project menu and then clicking on Save. The Map Canvas This is where the map itself is displayed and where layers are loaded. In the map canvas you can interact with the visible layers: zoom in/out, move the map, select features and many other operations that we will deeply see in the next sections. The Status Bar Shows you information about the current map. Also allows you to adjust the map scale, the map rotation and see the mouse cursor’s coordinates on the map. The Side Toolbar By default the Side toolbar contains the buttons to load the layer and all the buttons to create a new layer. But remember that you can move all the toolbars wherever it is more comfortable for you. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. The Locator Bar Within this bar you can access to almost all the objects of QGIS: layers, layer features, algorithms, spatial bookmarks, etc. Check all the different options in the Location setting 2. Tools 2.1 The Bottom Status Bar 1. the Status Bar, click on the Scale text field. 2. Type in 50000 and press Enter. This will redraw the features in the Map Canvas to reflect the scale you typed in. 3. Alternatively, click on the options arrow of the Scale field to see the present map scales. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  4. Select 1:5000. This will also update the map scale in the Map Canvas. 2.2 Layer Panel The layers panel (also called the map legend ) lists all the layers in the project and helps you manage their visibility. You can show or hide it by pressing Ctrl+1. A layer can be selected and dragged up or down in the legend to change the Z-ordering. Z-ordering means that layers listed nearer the top of the legend are drawn over layers listed lower down in the legend. Also a layer or a group of layers can be dragged across several QGIS instances. At the top of the Layers panel, a toolbar allows you to:  Open the layer styling dock (F7): toggle the layer styling panel on and off.  Add new group:  Manage Map Themes: control visibility of layers and arrange them in different map themes.  filter layers in the legend tree:  Filter Legend by Map Content : only the layers that are set visible and whose features intersect the current map canvas have their style rendered in the layers panel. Otherwise, a generic NULL symbol is applied to the layer. Based on the layer symbology, this is a convenient way to identify which kind of features from which layers cover your area of interest.  Show Private Layers : a convenient shortcut to display and interact with private layers in the layers panel without modifying the project settings.  Filter Legend by Expression: apply an expression to remove styles from the selected layer tree that have no feature satisfying the condition. This can be used to highlight features that are within a given area/feature of another layer. From the drop-down list, you can edit and clear the expression currently applied.  Expand All or Collapse All layers and groups in the layers panel.  Remove Layer/Group currently selected. 2.3 Bookmark This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. To create a bookmark: 1. Zoom and pan to the area of interest. 2. Select the menu option View ► New Spatial Bookmark… , press Ctrl+B or right- click the entry in the Browser panel and select Spatial Bookmarks New Spatial Bookmark. The Bookmark Editor dialog opens. Fig. The Bookmark Editor Dialog 3. Enter a descriptive name for the bookmark 4. Enter or select a group name in which to store related bookmarks 5. Select the extent of the area you wish to save, using the extent selector widget 6. Indicate the CRS to use for the extent 7. Select whether the bookmark will be Saved in User Bookmarks or Project Bookmarks 8. Press Save to add the bookmark to the list Note that you can have multiple bookmarks with the same name. To use and manage bookmarks, you can either use the Spatial Bookmarks panel or Browser. Select View ► Show Spatial Bookmark Manager or press Ctrl+7 to open the Spatial Bookmarks Manager panel. Select View ► Show Bookmarks or Ctrl+Shift+B to show the Spatial Bookmarks entry in the Browser panel. You can perform the following tasks: Task Spatial Bookmark Manager Browser Zoom to a Double-click on it, drag and drop it Double-click on it, or select the Bookmark to the map canvas, or right-click the This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Task Spatial Bookmark Manager Browser bookmark and select Zoom to bookmark and press the Zoom to Bookmark. bookmark button. Select the bookmark and click Right-click the bookmark and Delete a the Delete bookmark button. select Delete Spatial Bookmark. Confirm bookmark Confirm your choice. your choice. Select one or more folders (user or Click the Import/Export project) or subfolders (groups), then Export bookmarks Bookmarks button and select Export. right-click and select Export to XML All the bookmarks (user or project) are Spatial Bookmarks…. The selected saved in an xml file. bookmark subset is saved. Right-click the Spatial Bookmarks entry or one of its folders (user or project) Click the Import/Export or subfolders (groups) to determine Import where to import the bookmarks, then bookmarks Bookmarks button and select Import. from XML All bookmarks in the XML file are select Import Spatial Bookmarks. If imported as user bookmarks. performed on the Spatial Bookmarks entry, the bookmarks are added to User Bookmarks. Right-click the desired bookmark and select Edit Spatial Bookmark…. The Bookmark Editor will open, You can change a bookmark by allowing you to redefine every aspect Edit changing the values in the table. You of the bookmark as if you were bookmark can edit the name, the group, the extent creating it for the first time. and if it is stored in the project or not. You can also drag and drop the bookmark between folders (user and project) and subfolders (groups). 2.4 Measure length, areas, bearings and angles interactively Click the icon in the Attribute toolbar to begin measurements. The down arrow near the icon switches between length, area, bearing or angle. The default unit used in the dialog is the one set in Project ► Properties… ► General menu. For the Measure Line and the Measure Area the measurements can be done in Cartesian or Ellipsoidal measure. the Project ► Properties… ► General menu, and by the selection made in the measurement widget. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. All measuring modules use the snapping settings from the digitizing module (see section Setting the snapping tolerance and search radius). So, if you want to measure exactly along a line feature, or around a polygon feature, first set its layer snapping tolerance. Now, when using the measuring tools, each mouse click (within the tolerance setting) will snap to that layer. The Measure Line measures distances between given points. The tool then allows you to click points on the map. Each segment length, as well as the total, shows up in the measure window. To stop measuring, click the right mouse button. Now it is possible to copy all your line measurements at once to the clipboard using the Copy All button. Note that you can use the drop-down list near the total to change the measurement units interactively while working with the measure tool (‘Meters’, ‘Kilometers’, ‘Feet’, ‘Yards’, ‘Miles’, ‘Nautical miles’, ‘Centimeters’, ‘Millimeters’, ‘Degrees’, ‘Map units’). This unit is retained for the widget until a new project is created or another project is opened. The Info section in the dialog explains how calculations are made according to the CRS settings available. Fig. Measure Distance Measure Area: Areas can also be measured. In the measure window, the accumulated area size appears. Right-click to stop drawing. The Info section is also available as well as the ability to switch between different area units (‘Square meters’, This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. ‘Square kilometers’, ‘Square feet’, ‘Square yards’, ‘Square miles’, ‘Hectares’, ‘Acres’, ‘Square centimeters’, ‘Square millimeters’, ‘Square nautical miles’, ‘Square degrees’, ‘Map units’). Fig. Measure Area Measure Bearing: You can also measure bearings. The cursor becomes cross- shaped. Click to draw the first point of the bearing, then move the cursor to draw the second point. The measurement is displayed in a pop-up dialog. Fig. Measure Bearing Measure Angle: You can also measure angles. The cursor becomes cross-shaped. Click to draw the first segment of the angle you wish to measure, then move the cursor to draw the desired angle. The measurement is displayed in a pop-up dialog. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Fig Measure Angle 2.5 Navigation Toolbar 1. In the Map Navigation Toolbar, make sure the Pan button is activated. 2. Move the mouse to the center of the Map Canvas area. 3. Left-click and hold, and drag the mouse in any direction to pan the map. Next, let’s zoom in and take a closer look at the layers we imported. 1. In the Map Navigation Toolbar, click on the Zoom In button. 2. Move your mouse to approximately the top left area of where there is the highest density of buildings and roads. 3. Left click and hold. 4. Then drag the mouse, which will create a rectangle, and cover the dense area of buildings and roads (Fig. 2.5). This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Fig. Zoom in 5. Release the left click. This will zoom in to include the area that you selected with your rectangle. 6. To zoom out, select the Zoom Out button and perform the same action as you did for zooming in. As you pan, zoom in, or zoom out, QGIS saves these views in a history. This allows you to backtrack to a previous view. 1. In the Map Navigation Toolbar, click on Zoom Last button to go to your previous view. 2. Click on Zoom Next button to proceed to move forward in your history. Sometimes after exploring the data, we need to reset our view to the extent of all the layers. Instead of trying to use the Zoom Out tool multiple times, QGIS provides us with a button to do that action for us. 1. Click on the Zoom Full Extent button. Day-3: & Day 4 – Digitization Tool under the Settings ► Options… ► Digitizing menu, QGIS provides a number of parameters to configure default behaviour of editing tools. More information at Digitizing Settings. For optimal and accurate editing of vector layer geometries, we need to set an appropriate value of snapping tolerance and search radius for features vertices. The Snapping group provides related options, namely handling of the snapping tolerance and the search radius.  Snapping tolerance: When you add a new vertex or move an existing one, the snapping tolerance is the distance QGIS uses to search for the closest vertex or segment you are trying to connect to. If you are not within the snapping tolerance, QGIS will leave the vertex where you release the mouse button, instead of snapping it to an existing vertex or segment. The tolerance setting affects all tools that work with snapping and applies by default to new layers and projets. It can however be overridden at layer level (see Snapping and Digitizing Options). This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   Search radius: Search radius for vertex edits is the distance QGIS uses to search for the vertex to select when you click on the map. If you are not within the search radius, QGIS will not find and select any vertex for editing. Snap tolerance and search radius are set in map units or pixels. You may need to experiment to get them right. If you specify a too big tolerance, QGIS may snap to the wrong vertex, especially if you are dealing with a large number of vertices in close proximity. The smaller the search radius, the more difficult it will be to hit what you want to move. 3. Snapping and Digitizing Options Global snapping and digitizing settings (snapping mode, tolerance value, and units…) can be overridden in the project from the Project ► Snapping Options… menu. In the Snapping and Digitizing Options , you can also configure some other properties (snapping layers, scale limit, topology…) The guilabel:Snapping Toolbar gives access to most of these features. By default, snapping is disabled in a project until you press the Enable snapping button or press S. The snapping mode, tolerance value, and units can also be configured in this toolbar. 3.1 Snapping properties There are three options to select the layer(s) to snap to:  All layers : quick setting for all visible layers in the project so that the pointer snaps to all vertices and/or segments. In most cases, it is sufficient to use this snapping mode, but beware when using it for projects with many vector layers, as it may affect performance.  Current layer : only the active layer is used, a convenient way to ensure topological consistency within the layer being edited.  Advanced Configuration : allows you to enable and adjust snapping mode, tolerance and units, overlaps and scales of snapping on a layer basis (see Fig. 15.87). If you need to edit a layer and snap its vertices to another, make sure that the target layer is checked and increase the snapping tolerance to a higher value. Snapping will not occur to a layer that is not checked in the snapping options dialog. As for snapping mode, you can choose between Vertex , Segment , Area , Centroid , Middle of Segments and Line Endpoints. QGIS will show different snap icons depending on the kind of snap: This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Snapping to a vertex: box Snapping to a segment: Snapping to an intersection: icon hourglass icon cross icon Note that it is possible to change the color of these icons in the Digitizing part of the global settings. The tolerance values can be set either in the project’s map units or in pixels. The advantage of choosing pixels is that it keeps the snapping constant at different map scales. 10 to 12 pixels is normally a good value, but it depends on the DPI of your screen. Using map units allows the tolerance to be related to real ground distances. For example, if you have a minimum distance between elements, this option can be useful to ensure that you don’t add vertices too close to each other. Fig. Snapping options (Advanced Configuration mode) By default, only visible features (the features whose style is displayed, except for layers where the symbology is “No symbols”) can be snapped. You can enable the snapping on invisible features by checking Enable snapping on invisible features under the Settings ► Options ► Digitizing tab. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Enable snapping by default You can set snapping to be enabled by default on all new projects in the Settings ► Options ► Digitizing tab. You can also set the default snapping mode, tolerance value, and units, which will populate the Snapping Options dialog. 3.2 Enable snapping on intersections Another available option is to use snapping on intersection , which allows you to snap to geometry intersections of snapping enabled layers, even if there are no vertices at the intersections. 3.2.1 Limit snapping to a scale range In some cases snapping can become very slow. This is often caused by the amount of features in some layers that require a heavy index to compute and maintain. Some parameters exist to enable snapping only when the map view is inside a relevant scale range. This allows to only do the costly index computation related to snapping at a scale where drawing is relevant. Scale limit to snapping is configured in Project ► Snapping Options…. Limiting snapping to scale is only available in Advanced Configuration mode. To limit snapping to a scale range you have three modes available:  Disabled : Snapping is enabled whatever the current map scale is. This is the default mode.  Global : Snapping is limited and only enabled when the current scale of the map is between a global minimum and a global maximum value. When selecting this mode two widgets become available to configure the range of scales in which snapping is enabled.  Per layer : The snapping scale range limit is defined for each layer. When selecting this mode two columns become available to configure the minimum and maximum scales for each layer. Please note that the minimum and maximum scales follow the QGIS convention: minimum scale is the most “zoomed out” scale while maximum scale is the most “zoomed in”. A minimum or maximum scale that is set to “0” or “not set” is considered not limiting. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. 3.3 Self-snapping The Self-snapping option allows you to snap to the geometry that is being edited. Combined with the advanced digitizing panel, this provides a handy way to digitize new edges relative to the previous edges or vertices. Self-snapping can cause invalid geometries, use with caution. Fig. Drawing features with self-snapping Snapping on custom grid A snapping distance can also be customized on a layer basis in the Digitizing tab of the layer properties dialog. With setting the Geometry precision distance, you enable a dotted grid visible when the map canvas is at a coherent scale for display. Snapping can then be performed on the dots of the grid: an added or modified geometry will have all of its vertices snapped automatically to the closest node of the grid. More information at Digitizing Properties. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Topological editing In addition to these snapping options, the Snapping options… dialog ( Project ► Snapping options ) and the Snapping toolbar allow you to enable / disable some other topological functionalities. Enable topological editing The Topological editing button helps when editing and maintaining features with common boundaries. With this option enabled, QGIS ‘detects’ shared boundaries. When you move common vertices/segments, QGIS will also move them in the geometries of the neighboring features. Topological editing works with features from different layers, as long as the layers are visible and in editing mode. In layer with Z values, topological editing will interpolate the Z value of the vertex based on the value of the edge used for the connection. Overlapping control Overlapping prevents you from drawing new features that overlap existing ones in the selected layer, speeding up digitizing of adjacent polygons. It can be controlled by the overlap tool. Three modes are available: 1. Allow Overlap (default) 2. Avoid Overlap on Active Layer : prevents any overlap with other features from the layer being edited. Digitize the new geometries so that they overlap their neighbours and QGIS will cut the overlapping part(s) of the new geometries and snap them to the boundary of the existing features. The advantage is that you don’t have to digitize the common vertices on boundary. 3. Follow Advanced Configuration : allows the overlapping setting to be set on a layer basis in the Advanced configuration view mode. 3.4 Automatic Tracing Usually, when using capturing map tools (add feature, add part, add ring, reshape and split), you need to click each vertex of the feature. With the automatic tracing mode, you can speed This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  up the digitization process as you no longer need to manually place all the vertices during digitization: 1. Enable the Tracing tool (in the Snapping toolbar) by pushing the icon or pressing T key. 2. Snap to a vertex or segment of a feature you want to trace along. 3. Move the mouse over another vertex or segment you’d like to snap and, instead of the usual straight line, the digitizing rubber band represents a path from the last point you snapped to the current position. The tool also works with curved geometries. QGIS actually uses the underlying features topology to build the shortest path between the two points. Tracing requires snapping to be activated in traceable layers to build the path. You should also snap to an existing vertex or segment while digitizing and ensure that the two nodes are topologically connectable through existing features edges, otherwise QGIS is unable to connect them and thus traces a single straight line. 4. Click and QGIS places the intermediate vertices following the displayed path. Unfold the Enable Tracing icon and set the Offset option to digitize a path parallel to the features instead of tracing along them. A positive value shifts the new drawing to the left side of the tracing direction and a negative value does the opposite. Note Adjust map scale or snapping settings for an optimal tracing If there are too many features in map display, tracing is disabled to avoid potentially long tracing structure preparation and large memory overhead. After zooming in or disabling some layers the tracing is enabled again. Note Does not add topological points This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  This tool does not add points to existing polygon geometries even if Topological editing is enabled. If geometry precision is activated on the edited layer, the resulting geometry might not exactly follow an existing geometry. Tip Quickly enable or disable automatic tracing by pressing the T key By pressing the T key, tracing can be enabled/disabled anytime (even while digitizing a feature), so it is possible to digitize parts of the feature with tracing enabled and other parts with tracing disabled. Tools behave as usual when tracing is disabled. Tip Convert tracing to curved geometries By using Settings ► Options ► Digitizing ► Tracing you can create curved geometries while digitizing. See digitizing options. 3.5 Digitizing an existing layer By default, QGIS loads layers read-only. This is a safeguard to avoid accidentally editing a layer if there is a slip of the mouse. However, you can choose to edit any layer as long as the data provider supports it (see Exploring Data Formats and Fields), and the underlying data source is writable (i.e., its files are not read-only). Tip Restrict edit permission on layers within a project From the Project ► Properties… ► Data Sources ► Layers Capabilities table, you can choose to set any layer read-only regardless the provider permission. This can be a handy way, in a multi- users environment to avoid unauthorized users to mistakenly edit layers (e.g., Shapefile), hence potentially corrupt data. Note that this setting only applies inside the current project. In general, tools for editing vector layers are divided into a digitizing and an advanced digitizing toolbar, described in section Advanced digitizing. You can select and unselect both under View ► Toolbars ►. Using the basic digitizing tools, you can perform the following functions: Icon Purpose Icon Purpose This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Icon Purpose Icon Purpose Access to save, rollback or cancel Turn on or off edit status of changes in all or selected layers selected layer(s) based on the simultaneously active layer status Save edits to the active layer Add new record Add Feature: Capture Point Add Feature: Capture Line Add Feature: Capture Polygon Vertex Tool (All Layers) Vertex Tool (Current Layer) Modify the attributes of all selected features simultaneously Delete Selected features from the active Cut Features from the active layer layer Copy selected Features from the active Paste Features into the active layer layer Undo changes in the active layer Redo changes in active layer Table Editing: Vector layer basic editing toolbar Note that while using any of the digitizing tools, you can still zoom or pan in the map canvas without losing the focus on the tool. All editing sessions start by choosing the Toggle editing option found in the context menu of a given layer, from the attribute table dialog, the digitizing toolbar or the Layer menu. Once the layer is in edit mode, additional tool buttons on the editing toolbar will become available and markers will appear at the vertices of all features unless Show markers only for selected features option under Settings ► Options… ► Digitizing menu is checked. Tip Save Regularly Remember to Save Layer Edits regularly. This will also check that your data source can accept all the changes. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. 3.6 Adding Features Depending on the layer type, you can use the Add Record, Add Point Feature, Add Line Feature or Add Polygon Feature icons on the toolbar to add new features into the current layer. To add a geometryless feature, click on the Add Record button and you can enter attributes in the feature form that opens. To create features with the spatially enabled tools, you first digitize the geometry then enter its attributes. To digitize the geometry: 1. Left-click on the map area to create the first point of your new feature. For point features, this should be enough and trigger, if required, the feature form to fill in their attributes. 2. For line or polygon geometries, keep on left-clicking for each additional point you wish to capture. You can rely on the snapping to features options, the snap-to- grid or the advanced digitizing panel to accurately position each vertex. Along with placing nodes clik by click, lines and polygons can be:  traced automatically, accelerating the digitization. This will create consecutive straight lines between the vertices you place.  free-hand digitized, pressing R or activating Stream digitizing in the Advanced Digitizing Toolbar. Note Pressing Delete or Backspace key reverts the last node you add. 3. When you have finished adding points, right-click anywhere on the map area to confirm you have finished entering the geometry of that feature. Note While digitizing line or polygon geometries, you can switch back and forth between the linear Add feature tools and circular string tools to create compound curved geometries. Tip Customize the digitizing rubber band This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  While capturing polygon, the by-default red rubber band can hide underlying features or places you’d like to capture a point. This can be fixed by setting a lower opacity (or alpha channel) to the rubber band’s Fill Color in Settings ► Options ► Digitizing menu. You can also avoid the use of the rubber band by checking Don’t update rubber band during node editing. 4. For line feature pressing Shift + right-click will close the line automatically. 5. The attribute window will appear, allowing you to enter the information for the new feature. Fig. 15.89 shows setting attributes for a fictitious new river. However, in the Digitizing menu under the Settings ► Options menu, you can also:  Suppress attributes pop-up windows after each created feature to avoid the form opening;  or Reuse last entered attribute values to have fields automatically filled at the opening of the form and just have to type changing values. Fig. Enter Attribute Values Dialog after digitizing a new vector feature 3.7 Vertex tool QGIS provides two tools to interact with vector features vertices:  Vertex Tool (Current Layer): only overlaid features in the active layer (in the Layers panel) are affected  : any overlaid features in all editable layers are affected. This Vertex Tool (All Layers) allows you to edit features without switching the active layer or edit multiple layers at once (e.g., country and their regions boundaries) For any editable vector layer, the vertex tools provide manipulation capabilities of feature vertices similar to CAD programs. It is possible to select multiple vertices at once and to move, add or delete them altogether. The vertex tools also support the topological editing This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  feature. They are selection persistent, so when some operation is done, selection stays active for this feature and tool. It is important to set the property Settings ► Options ► Digitizing ► Search Radius: to a number greater than zero. Otherwise, QGIS will not be able to tell which vertex is being edited and will display a warning. Tip Vertex Markers QGIS supports different kinds of vertex markers: ‘Semi-transparent circle’, ‘Cross’ and ‘None’. To change the marker style, choose Options from the Settings menu, click on the Digitizing tab and select the appropriate entry. Basic operations Given a layer in edit mode, start by activating the vertex tool. Red circles will appear when hovering vertices.  Selecting vertices: You can select vertices by:  Clicking on them one at a time holding Shift key pressed  Click-and-dragging a rectangle surrounding the target vertices  Drawing a polygon surrounding the target vertices: Hold Alt and click using the vertex tool to start digitizing a polygon. Each subsequent click adds a new vertex to the rubberband polygon. Backspace or Delete removes last added rubberband vertex. Esc cancels the polygon selection mode, as also does backspacing/deleting all of the rubberband’s vertices. Right click finalizes the polygon digitizing and selects all vertices within the rubberband polygon. When a vertex is selected, its color changes to blue. To add more vertices to the current selection, hold down the Shift key while proceeding as above. To remove vertices from the selection, hold down Ctrl. Tip Feature selection bounds vertex tool This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Vertices can be selected accross different features (or layers). If you are looking for vertices of a specific feature in a crowded place, first select that feature. Then draw the rectangle or polygon selector with the vertex tool around the vertices: only the selected feature’s vertices are selected. This is also the case if you display the feature in the vertex editor panel.  Batch vertex selection mode: The batch selection mode can be activated by pressing Shift+R. Select a first node with one single click, and then hover without clicking another vertex. This will dynamically select all the nodes in between using the shortest path (for polygons). Fig. 15.90 Batch vertex selection using Shift+R Press Ctrl will invert the selection, selecting the longest path along the feature boundary. Ending your node selection with a second click, or pressing Esc will escape the batch mode.  Adding vertices: To add a vertex to a line or polygon geometry, hold Shift and double-click the place on the segment. When hovering a segment, a virtual new node appears on the center. Click on it, move the cursor to a new location and click again to add a new vertex. For lines, a virtual node is also proposed at both extremities: click on it, do subsequent clicks and finish with a right-click; this allows to easily extend an existing line. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Fig. Virtual nodes for adding vertices  Deleting vertices: Select the vertices and click the Delete key. Deleting all the vertices of a feature generates, if compatible with the datasource, a geometryless feature. Note that this doesn’t delete the complete feature, just the geometry part. To delete a complete feature use the Delete Selected tool.  Moving vertices: Select all the vertices you want to move, click on a selected vertex or edge, and click on the desired new location. You can use the snapping to feature capabilities and the Advanced Digitizing Panel constraints for distance, angles, exact X and Y location before the second click. All the selected vertices will be translated. However, if the snap-to-grid option is enabled, selected vertices are snapped to the closest grid intersection to their translated position. Unselected vertices are also moved to their closest grid intersection. There is no simple translation. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Fig. Moving the top vertex snaps all the vertices to the grid Each change made with the vertex tool is stored as a separate entry in the Undo dialog. Remember that all operations support topological editing when this is turned on. On-the-fly projection is also supported. 3.8 The Vertex Editor Panel With enabling a vertex tool, you also open the Vertex Editor panel. Right-clicking over a feature fills the panel with the list of all the vertices of the feature with their x , y ( z , m if applicable) coordinates and r (for the radius, in case of circular geometry). The feature is also made exclusive for editing, meaning that the edit of any other features is disabled: new vertices can only be added to the bound feature, selecting and moving of vertices and segments by clicking or dragging the map canvas is only possible for that feature. Also, select a row in the table does select the corresponding vertex in the map canvas, and vice versa. Change a coordinate in the table and the vertex position is updated. You can also select multiple rows and delete them altogether. Fig. Vertex editor panel showing selected nodes 3.9 Cutting, Copying and Pasting Features Copy a line feature and paste it in a polygon layer: QGIS pastes in the target layer a polygon whose boundary corresponds to the closed geometry of the line feature. This is a quick way to generate different geometries of the same data. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Features can also be pasted to external applications as text. That is, the features are represented in CSV format, with the geometry data appearing in the OGC Well-Known Text (WKT) format. WKT and GeoJSON features from outside QGIS can also be pasted to a layer within QGIS. When would the copy and paste function come in handy? Well, it turns out that you can edit more than one layer at a time and copy/paste features between layers. Why would we want to do this? Say we need to do some work on a new layer but only need one or two lakes, not the 5,000 on our big_lakes layer. We can create a new layer and use copy/paste to plop the needed lakes into it. As an example, we will copy some lakes to a new layer: 1. Load the layer you want to copy from (source layer) 2. Load or create the layer you want to copy to (target layer) 3. Start editing for target layer 4. Make the source layer active by clicking on it in the legend 5. Use the Select Features by area or single click tool to select the feature(s) on the source layer 6. Click on the Copy Features tool 7. Make the destination layer active by clicking on it in the legend 8. Click on the Paste Features tool 9. Stop editing and save the changes What happens if the source and target layers have different schemas (field names and types are not the same)? QGIS populates what matches and ignores the rest. If you don’t care about the attributes being copied to the target layer, it doesn’t matter how you design the fields and data types. If you want to make sure everything - the feature and its attributes - gets copied, make sure the schemas match. 15.3.4.4. Deleting Selected Features If we want to delete an entire feature (attribute and geometry), we can do that by first selecting the geometry using the regular Select Features by area or single click tool. Selection can also be done from the attribute table. Once you have the selection set, press Delete or Backspace key or use the Delete Selected tool to delete the features. Multiple selected features can be deleted at once. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. The Cut Features tool on the digitizing toolbar can also be used to delete features. This effectively deletes the feature but also places it on a “spatial clipboard”. So, we cut the feature to delete. We could then use the Paste Features tool to put it back, giving us a one-level undo capability. Cut, copy, and paste work on the currently selected features, meaning we can operate on more than one at a time. 15.3.4.5. Undo and Redo The Undo and Redo tools allows you to undo or redo vector editing operations. There is also a dockable widget, which shows all operations in the undo/redo history (see Fig. 15.94). This widget is not displayed by default; it can be displayed by right-clicking on the toolbar and activating the Undo/Redo Panel checkbox. The Undo/Redo capability is however active, even if the widget is not displayed. Fig. 15.94 Redo and Undo digitizing steps When Undo is hit or Ctrl+Z (or Cmd+Z) pressed, the state of all features and attributes are reverted to the state before the reverted operation happened. Changes other than normal vector editing operations (for example, changes done by a plugin) may or may not be reverted, depending on how the changes were performed. To use the undo/redo history widget, simply click to select an operation in the history list. All features will be reverted to the state they were in after the selected operation. 15.3.4.6. Saving Edited Layers When a layer is in editing mode, any changes remain in the memory of QGIS. Therefore, they are not committed/saved immediately to the data source or disk. If you want to save This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. edits to the current layer but want to continue editing without leaving the editing mode, you can click the Save Layer Edits button. When you turn editing mode off with Toggle editing (or quit QGIS for that matter), you are also asked if you want to save your changes or discard them. If the changes cannot be saved (e.g., disk full, or the attributes have values that are out of range), the QGIS in-memory state is preserved. This allows you to adjust your edits and try again. Saving multiple layers at once This feature allows the digitization of multiple layers. Choose Save for Selected Layers to save all changes you made in multiple layers. You also have the opportunity to Rollback for Selected Layers , so that the digitization may be withdrawn for all selected layers. If you want to stop editing the selected layers, Cancel for Selected Layer(s) is an easy way. The same functions are available for editing all layers of the project. Icon Purpose Icon Purpose Enable Advanced Digitizing Tools Enable Stream Digitize with Curve Digitizing Copy and Move Move Feature(s) Feature(s) Rotate Feature(s) Simplify Feature Scale Feature Add Ring Add Part Fill Ring Swap direction Delete Ring Delete Part Offset Curve Reshape Features Split Parts Split Features This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Icon Purpose Icon Purpose Merge Attributes of Selected Merge Selected Features Features Rotate Point Symbols Offset Point Symbols Trim or Extend Feature Straight, curve and stream digitizing The Digitize with Curve tool allows you to draw curves in layers with geometries that support curves. Digitizing a curve requires to provide three points along the curve (start, point along the arc, end) which define it. The Stream Digitizing tool allows you to activate and deactivate stream digitizing which allows to create features in freehand mode. The streaming tolerance affects the spacing between consecutive vertices. Currently, the only supported unit is pixels ( px ) Move Feature(s) The Move Feature(s) tool allows you to move existing features: 1. Select the feature(s) to move. 2. Click on the map canvas to indicate the origin point of the displacement; you can rely on snapping capabilities to select an accurate point. You can also take advantages of the advanced digitizing constraints to accurately set the origin point coordinates. In that case: 1. First click on the button to enable the panel. 2. Type x and enter the corresponding value for the origin point you’d like to use. Then press the button next to the option to lock the value. 3. Do the same for the y coordinate. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  4. Click on the map canvas and your origin point is placed at the indicated coordinates. 3. Move over the map canvas to indicate the destination point of the displacement, still using snapping mode or, as above, use the advanced digitizing panel which would provide complementary distance and angle placement constraints to place the end point of the translation. 4. Click on the map canvas: the whole features are moved to new location. Likewise, you can create a translated copy of the feature(s) using the Copy and Move Feature(s) tool. 15.3.5.3. Rotate Feature(s) Use the Rotate Feature(s) tool to rotate one or multiple features in the map canvas: 1. Press the Rotate Feature(s) icon 2. Then click on the feature to rotate. The feature’s centroid is referenced as rotation center, a preview of the rotated feature is displayed and a widget opens showing the current Rotation angle. 3. Click on the map canvas when you are satisfied with the new placement or manually enter the rotation angle in the text box. You can also use the Snap to ° box to constrain the rotation values. 4. If you want to rotate several features at once, they shall be selected first, and the rotation is by default around the centroid of their combined geometries. You can also use an anchor point different from the default feature centroid: press the Ctrl button, click on the map canvas and that point will be used as the new rotation center. If you hold Shift before clicking on the map, the rotation will be done in 45 degree steps, which can be modified afterwards in the user input widget. To abort feature rotation, press the ESC button or click on the Rotate Feature(s) icon. 15.3.5.4. Scale Feature The Scale Feature tool is similar to the Rotate feature. Though instead of performing a rotation of selected features, it rescales their geometry. The change is performed in relation to the This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. anchor point and the scale ratio can be manually specified in the widget that appears in the upper corner of the canvas. 15.3.5.5. Simplify Feature The Simplify Feature tool allows you to interactively reshape a line or polygon geometry by reducing or densifying the number of vertices, as long as the geometry remains valid: 1. Select the Simplify Feature tool. 2. Click on the feature or drag a rectangle over the features. 3. A dialog pops up allowing you to define the Method to apply, ie whether you would like to:  simplify the geometry, meaning less vertices than the original. Available methods are Simplify by distance , Simplify by snapping to grid or simplify by area (Visvalingam). You’d then need to indicate the value of Tolerance in Layer units , Pixels or map units to use for simplification. The higher the tolerance is the more vertices can be deleted.  or densify the geometries with new vertices thanks to the Smooth option: for each existing vertex, two vertices are placed on each of the segments originated from it, at an Offset distance representing the percentage of the segment length. You can also set the number of Iterations the placement would be processed: the more iterations, the more vertices and smoother is the feature. Settings that you used will be saved when leaving a project or an edit session. So you can go back to the same parameters the next time you simplify a feature. 4. A summary of the modifications that would apply is shown at the bottom of the dialog, listing number of features and number of vertices (before and after the operation and the ratio the change represents). Also, in the map canvas, the expected geometry is displayed over the existing one, using the rubberband color. When the expected geometry fits your needs, click OK to apply the modification. Otherwise, to abort the operation, you can either press Cancel or right-click in the map canvas. Reshape Features This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. You can reshape line and polygon features using the Reshape Features tool on the toolbar. For lines, it replaces the line part from the first to the last intersection with the original line. Fig. Reshape line Use the Reshape Features tool to extend existing linestring geometries: snap to the first or last vertex of the line and draw a new one. Validate and the feature’s geometry becomes the combination of the two lines. For polygons, it will reshape the polygon’s boundary. For it to work, the reshape tool’s line must cross the polygon’s boundary at least twice. To draw the line, click on the map canvas to add vertexes. To finish it, just right-click. Like with the lines, only the segment between the first and the last intersections is considered. The reshape line’s segments that are inside the polygon will result in cropping it, where the ones outside the polygon will extend it. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Fig. Reshape polygon With polygons, reshaping can sometimes lead to unintended results. It is mainly useful to replace smaller parts of a polygon, not for major overhauls, and the reshape line is not allowed to cross several polygon rings, as this would generate an invalid polygon. Reverse Line Changing the direction of a line geometry can be useful for cartographical purposes or when preparing for network analysis. To change a line direction: 1. Activate the reverse line tool by clicking Reverse line. 2. Click on the line. The direction of the line is reversed. Split Features Use the Split Features tool to split a feature into two or more new and independent features, ie. each geometry corresponding to a new row in the attribute table. To split line or polygon features: 1. Select the Sp lit Features tool. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  2. Draw a line across the feature(s) you want to split. If a selection is active, only selected features are split. When set, default values or clauses are applied to corresponding fields and other attributes of the parent feature are by default copied to the new features. 3. You can then as usually modify any of the attributes of any resulting feature. LABEL Labels are textual information you can display on vector features or maps. They add details you could not necessarily represent using symbols. Two types of text-related items are available in QGIS:  Text Format : defines the appearance of the text, including font, size, colors, shadow, background, buffer, … They can be used to render texts over the map (layout/map title, decorations, scale bar, …), usually through the font widget. To create a Text Format item: 1. Open the Style Manager dialog 2. Activate the Text format tab Fig. 13.17 Text formats in Style Manager dialog 3. Press the Add item button. The Text Format dialog opens for configuration. As usual, these properties are data-definable. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   Label Settings : extend the text format settings with properties related to the location or the interaction with other texts or features (callouts, placement, overlay, scale visibility, mask …). They are used to configure smart labelling for vector layers through the Labels tab of the vector Layer Properties dialog or Layer Styling panel or using the Layer Labeling Options button of the Label toolbar. To create a Label Settings item: 1. Open the Style Manager dialog 2. Activate the Label Settings tab Fig. 13.18 Label Settings in Style Manager dialog 3. Press the Add item menu and select the entry corresponding to the geometry type of the features you want to label. The Label Settings dialog opens with the following properties. As usual, these properties are data-definable. Formatting the label text Whether you are configuring a Text Format or Label Settings item, you will be given the following options: Properties tab Text format Label settings Text Formatting Buffer This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Properties tab Text format Label settings Mask Background Shadow Callout Placement Rendering Text tab This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Fig. 13.19 Labels settings - Text tab In the Texttab, you can set:  the Font , from the ones available on your machine  the Style : along with the common styles of the font, you can set whether the text should be underlined or striked through  the Size in any supported unit  the Color  the Opacity  and Allow HTML Formatting : The HTML formatting option enables the proper rendering of some HTML tags to customize the label. The supported tags are the HTML Color tags (applied to text, underline, strikethrough, and overline). In order to use the HTML formatting, you need to provide the HTML code in the Value field. The expression is parsed and any supported HTML tag overrides its corresponding setting in the labels properties. They also combine well with other background, shadow, buffer… properties of labels. Below an example of a HTML-based expression and rendering (applies different colors and underline to the same label): format( '%1 ( %2 ft )', title( lower( "Name" ) ), round($length) ) This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  Fig. 13.20 Labeling with HTML formatting enabled At the bottom of the tab, a widget shows a filterable list of compatible items stored in your style manager database. This allows you to easily configure the current text format or label setting based on an existing one, and also save a new item to the style database: Press the Save format… or Save settings… button and provide a name and tag(s). Note When configuring a Label Settings item, text format items are also available in this widget. Select one to quickly overwrite the current textual properties of the label. Likewise, you can create/overwrite a text format from there. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. 13.3.1.2. Formatting tab Fig. Label settings - Formatting tab This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. In the tab, you can: Formatting  Use the Type case option to change the capitalization style of the text. You have the possibility to render the text as: o No change o All uppercase o All lowercase o Title case : modifies the first letter of each word into capital, and turns the other letters into lower case if the original text is using a single type case. In case of mixed type cases in the text, the other letters are left untouched. o Force first letter to capital : modifies the first letter of each word into capital and leaves the other letters in the text untouched.  Under Spacing , change the space between words and between individual letters.  of the text font Enable kerning  Set the Text orientation which can be Horizontal or Vertical. It can also be Rotation-based when setting a label (e.g., to properly label line features in parallel placement mode).  Use the Blend mode option to determine how your labels will mix with the map features below them (more details at Blending Modes).  The Apply label text substitutes option allows you to specify a list of texts to substitute to texts in feature labels (e.g., abbreviating street types). Replacement texts are used when displaying labels on the map. Users can also export and import lists of substitutes to make reuse and sharing easier.  Configure Multiple lines : o Set a character that will force a line break in the text with the Wrap on character option o Set an ideal line size for auto-wrapping using the Wrap lines to option. The size can represent either the Maximum line length or the Minimum line length. o Decide the Line Height o Format the Alignment : typical values available are Left , Right , Justify and Center. When setting point labels properties, the text alignment can also be Follow label placement. In that case, the alignment will depend on the final placement of the label relative to the point. E.g., if the label is placed to the left of the point, then the label will be This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  right aligned, while if it is placed to the right, it will be left aligned.  Note  The Multiple lines formatting is not yet supported by curve based label placement. The options will then be deactivated.  For line labels you can include Line direction symbol to help determine the line directions, with symbols to use to indicate the Left or Right. They work particularly well when used with the curved or Parallel placement options from the Placement tab. There are options to set the symbols position, and to Reverse direction.  Use the Formatted numbers option to format numeric texts. You can set the number of Decimal places. By default, 3 decimal places will be used. Use the Show plus sign if you want to show the plus sign for positive numbers. 13.3.1.3. Buffer tab Fig. Label settings - Buffer tab To create a buffer around the label, activate the Draw text buffer checkbox in the Buffer tab. Then you can: This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   Set the buffer’s Size in any supported unit  Select the buffer’s Color  Color buffer’s fill : The buffer expands from the label’s outline, so, if the option is activated, the label’s interior is filled. This may be relevant when using partially transparent labels or with non-normal blending modes, which will allow seeing behind the label’s text. Unchecking the option (while using totally transparent labels) will allow you to create outlined text labels.  Define the buffer’s Opacity  Apply a Pen join style : it can be Round , Miter or Bevel  Use the Blend mode option to determine how your label’s buffer will mix with the map components below them (more details at Blending Modes).  Check Draw effects to add advanced paint effects for improving text readability, eg through outer glows and blurs. 13.3.1.4. Background tab The Background tab allows you to configure a shape that stays below each label. To add a background, activate the Draw Background checkbox and select the Shape type. It can be:  a regular shape such as Rectangle , Square , Circle or Ellipse using full properties of a fill symbol  an SVG symbol from a file, a URL or embedded in the project or style database (more details)  or a Marker Symbol you can create or select from the symbol library. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Fig. 13.23 Label settings - Background tab Depending on the selected shape, you need to configure some of the following properties:  The Size type of the frame, which can be: o Fixed : using the same size for all the labels, regardless the size of the text o or a Buffer over the text’s bounding box  The Size of the frame in X and Y directions, using any supported units  A Rotation of the background, between Sync with label , Offset of label and Fixed. The last two require an angle in degrees. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   An Offset X,Y to shift the background item in the X and/or Y directions  A Radius X,Y to round the corners of the background shape (applies to rectangle and square shapes only)  An Opacity of the background  A Blend mode to mix the background with the other items in the rendering (see Blending Modes).  For SVG symbol, you can use its default properties ( Load symbol parameters ) or set a custom Fill color , Stroke color and Stroke width.  to add advanced Draw effects paint effects for improving text readability, eg through outer glows and blurs. 13.3.1.5. Shadow tab Fig. Label settings - Shadow tab This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. To add a shadow to the text, enable the Shadow tab and activate the Draw drop shadow. Then you can:  Indicate the item used to generate the shadow with Draw under. It can be the Lowest label component or a particular component such as the Text itself, the Buffer or the Background.  Set the shadow’s Offset from the item being shadowded, ie: o The angle: clockwise, it depends on the underlying item orientation o The distance of offset from the item being shadowded o The units of the offset If you tick the Use global shadow checkbox, then the zero point of the angle is always oriented to the north and doesn’t depend on the orientation of the label’s item.  Influence the appearance of the shadow with the Blur radius. The higher the number, the softer the shadows, in the units of your choice.  Define the shadow’s Opacity  Rescale the shadow’s size using the Scale factor  Choose the shadow’s Color  Use the Blend mode option to determine how your label’s shadow will mix with the map components below them (more details at Blending Modes). Mask tab The Mask tab allows you to define a mask area around the labels. This feature is very useful when you have overlapping symbols and labels with similar colors, and you want to make the labels visible. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Fig. 13.25 Labels settings - Mask tab To create masking effects on labels: 1. Activate the Enable mask checkbox in the tab. 2. Then you can set:  the mask’s Size in the supported units  the Opacity of the mask area around the label  a Pen Join Style  paint effects through the Draw effects checkbox. 3. Select this mask shape as a mask source in the overlapping layer properties Mask tab (see Masks Properties). This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. 13.3.2.2. Callouts tab A common practice when placing labels on a crowded map is to use callouts - labels which are placed outside (or displaced from) their associated feature are identified with a dynamic line connecting the label and the feature. If one of the two endings (either the label or the feature) is moved, the shape of the connector is recomputed. Fig. 13.26 Labels with various callouts settings This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. To add a callout to a label, enable the Callouts tab and activate the Draw callouts. Then you can: 1. Select the Style of connector, one of:  Simple lines : a straight line, the shortest path  Manhattan style : a 90° broken line  Curved lines : a curved line  Balloons : a speech bubble surrounding the label and pointing to the feature. It can have rounded corners. 2. For a line-based callout: 1. Select the Line style with full capabilities of a line symbol including layer effects, and data-defined settings 2. If curved, you also define:  the percentage of Curvature of the connection line  and its Orientation : starting from the label to the feature, it can be Clockwise or Counter-clockwise , or Automatic (determining an optimal orientation for each label) 3. Set the Minimum length of callout lines 4. Check whether to Draw lines to all feature parts from the feature’s label 5. Set the Label anchor point : controls where the connector line should join to the label text. Available options:  Closest point  Centroid  Fixed position at the edge ( Top left , Top center , Top right , Left middle , Right middle , Bottom left , Bottom center and Bottom right ). 6. Set the Offset from label area option: controls the distance from the label anchor point (where the callout line ends). This avoids drawing lines right up against the text. 3. For a balloon callout, you’d need to set:  the Fill style with full capabilities of a fill symbol including layer effects, and data-defined settings  the Corner radius of the speech bubble  the Wedge width : how large the bubble speech connection with feature’s pointer should be This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   the around the label’s text Margins 4. Set the Offset from feature option: controls the distance from the feature (or its anchor point if a polygon) where callout lines end. Eg, this avoids drawing lines right up against the edges of the features. 5. Set the Feature anchor point for the (polygon) feature (the end point of the connector line). Available options:  Pole of inaccessibility  Point on exterior  Point on surface  Centroid 6. Set the Blend mode : controls the blending of the callout. Under the Data defined placement group, coordinates of the Origin (on the label side) and/or Destination (on the feature side) points of the callout can be controlled. Callouts can also be controlled manually by using the Move Label, Diagram or Callout tool in the Labeling Toolbar. The start and end points of each callout can be moved this way. The nodes should be highlighted when the mouse pointer is nearby. If needed the Shift Key can be held during the movement. This will snap the point in a way that the angle between the two callout points increments by 15 degrees. 13.3.2.3. Placement tab Choose the Placement tab for configuring label placement and labeling priority. Note that the placement options differ according to the type of vector layer, namely point, line or polygon, and are affected by the global PAL setting. Placement for point layers Point labels placement modes available are:  Cartographic : point labels are generated with a better visual relationship with the point feature, following ideal cartographic placement rules. Labels can be placed: o at a set Distance in supported units, either from the point feature itself or from the bounds of the symbol used to represent the feature (set in Distance offset from ). The latter option is especially useful when the symbol size isn’t fixed, e.g. if it’s set by a data defined size or when using different symbols in a categorized renderer. This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  o following a Position priority that can be customized or set for an individual feature using a data defined list of prioritised positions. This also allows only certain placements to be used, so e.g. for coastal features you can prevent labels being placed over the land. By default, cartographic mode placements are prioritised in the following order (respecting the guidelines from Krygier and Wood (2011) and other cartographic textbooks): 1. top right 2. top left 3. bottom right 4. bottom left 5. middle right 6. middle left 7. top, slightly right 8. bottom, slightly left.  Around Point : labels are placed in a circle around the feature. equal radius (set in Distance ) circle around the feature. The placement priority is clockwise from the “top right”. The position can be constrained using the data-defined Quadrant option.  Offset from Point : labels are placed at an Offset X,Y distance from the point feature, in various units, or preferably over the feature. You can use a data- defined Quadrant to constrain the placement and can assign a Rotation to the label. Placement for line layers Label modes for line layers include:  Parallel : draws the label parallel to a generalised line representing the feature, with preference for placement over straighter portions of the line. You can define: o Allowed positions : Above line , On line , Below line and Line orientation dependent position (placing the label at the left or the right of the line). It’s possible to select several options at once. In that case, QGIS will look for the optimal label position. o Distance between the label and the line This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   Curved :draws the label following the curvature of the line feature. In addition to the parameters available with the Parallel mode, you can set the Maximum angle between curved characters , either inside or outside.  Horizontal : draws labels horizontally along the length of the line feature. Fig. 13.27 Label placement examples for lines Next to placement modes, you can set:  Repeating Labels Distance to display multiple times the label over the length of the feature. The distance can be in Millimeters , Points , Pixels , Meters at scale , Map Units and Inches.  A Label Overrun Distance (not available for horizontal mode): specifies the maximal allowable distance a label may run past the end (or start) of line features. Increasing this value can allow for labels to be shown for shorter line features.  Label Anchoring : controls the placement of the labels along the line feature they refer to. Click on Settings … to choose: o the position along the line (as a ratio) which labels will be placed close to. It can be data-defined and possible values are: This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.   Center of Line  Start of Line  End of Line or Custom…. o Clipping : Determines how the label placement on a line is calculated. By default only the visible extent of the line is used but the whole extent can be used to have more consistent results. o Placement Behavior : use Preferred Placement Hint to treat the label anchor only as a hint for the label placement. By choosing Strict , labels are placed exactly on the label anchor. Placement for polygon layers You can choose one of the following modes for placing labels of polygons: This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission. Fig. 13.28 Label placement examples for polygons  Offset from Centroid : labels are placed over the feature centroid or at a fixed Offset X,Y distance (in supported units) from the centroid. The reference centroid can be determined based on the part of the polygon This document is submitted solely for AABSyS internal communication. It may not be duplicated, used, or disclosed in whole or in part for any other purpose without AABSyS prior written permission.  rendered in the map canvas ( visible polygon ) or the whole polygon , no matter if you can see it. You can also: o force the centroid point to lay inside their polygon o place the label within a specific quadrant o assign a rotation o Allow placing labels outside of polygons when it is not possible to place them inside the polygon. Thanks to data-defined properties, this makes possible to either allow outside labels, prevent outside labels, or force outside labels on a feature-by- feature basis.  Around Centroid : places the label within a preset distance around the centroid, with a preference for the placement directly over the centroid. Again, you can define whether the centroid is the one of the visible polygon or the whole polygon , and whether to force the centroid point inside the polygon.  Horizontal : places at the best pos