Geodesic Tools

This QGIS3 plugin is developed to expand the set of tools for geodesic work in QGIS. The main functionalities of the plugin are

• rectangular mapping
• finding intersection point of a line and a circle
• finding intersection point of two lines
• displacing a line feature

In addition to these main functionalities the plugin contains tools for data manipulation (e.g. explode polygon to lines or split a line).

Please report issues preferably to Issues or to info@gispo.fi. The plugin is not actively developed, but if you want to support the development or request a feature, do not hesitate to contact us.

Developed by Gispo Ltd.

Installation instructions

1. Via official QGIS plugin repository: Launch QGIS and navigate to the plugins menu by selecting Plugins > Manage and Install Plugins from the top menu. Go to All tab and search for Geodesic Tools and click Install Plugin!

2. From ZIP-file: Navigate to Releases and under the newest release's Assets section click kimu.Va.b.z.zip in order to download the plugin as a ZIP file. Lauch QGIS and navigate to plugins menu (as in 1), but this time, go to Install from ZIP tab, set the correct path to the ZIP file you just downloaded and click Install Plugin!

As a result, a new toolbar emerges into QGIS:

Usage

Rectangular mapping

Practical example of the use case: User aims to map corner points for a rectangular building so that first corner point of the building is mapped against the specified boundary line. The location of the first corner point is 36.2 meters (A measure) along the selected property boundary line and 27.8 meters (B measure) into the property. The building consists of four corner points whose distances to each other (starting from first corner point located via A and B measures) are: 8.2, 13.6, 8.2 and 13.6 meters.

1. Make sure that you have a line layer active in the Layers panel.

2. Utilize QGIS's selection tools to select (exactly one) line feature against which yuo want to start the rectangular mapping procedure:

3. Click Rectangular mapping button -> the panel opens up into the right side of the QGIS.

4. In the panel, insert values for A and B measures to be applied. Press Enter.

• Give the A and B measures in coordinate reference system units (e.g. for EPG:3067 in meters)
• A measure specifies the distance you wish to move from the selected line feature's start / end point along the selected line feature (or its extent)
• B measure specifies the distance you wish to move orthogonally from the chosen Point A
• A and/or B measures can be zero, too

5. In the panel, insert a list of values specifying the distances between rectangularly mapped points

• Give the distances in coordinate reference system units (e.g. for EPG:3067 in meters)
• Separate each distance value with comma
• Do not use any additional characters (e.g. spaces)
• This list can be left empty, too (if you just wish to locate Point B)
• Note that in order to rectangularly map X points, you only need to insert X-1 distances (in our practical example, three inserted wall lengths specify the locations of all four building corner points)
• However, if you insert "an extra" distance in the list, it does not matter since the tool has a check preventing it from mapping duplicate points

6. Select already existing file (e.g. geopackage) into which you wish to store the obtained result layer.

• The coordinate reference system of the file must match with the coordinate reference system of the active layer!
• You can leave this file path also empty

7. Click start / end point of the selected line feature to determine the point from which the tool will start the rectangular mapping.
8. Answer to the questions the tool asks from you via a pop-up window.

In action:

Note. The tool automatically enables suitable snapping configurations.

Intersect line and circle

1. Use the QGIS selection tools to select one line feature or two point features (that will form a line):

2. Click Intersect line and circle button -> the panel opens up into the right side of the QGIS.

3. In the panel, insert a value for the implicitly definable circle radius. Press Enter.

• Give the size of the radius in coordinate reference system units (e.g. for EPG:3067 in meters)

4. Click any point feature / vertex point visible in the map canvas to be used as a centroid of the implicitly defined circle.

5. Select which intersection point you wish to keep. While the pop-up window is open, the circle is shown as a temporary feature.

• If the line does not genuinely intersect with the implicitly defined circle (just touches it), the tool will automatically show only 1 point

6. Select already existing file (e.g. geopackage) into which you wish to store the obtained result point.

• The coordinate reference system of the file must match with the coordinate reference system of the active layer!
• You can leave this file path also empty if you only need a QGIS temporary layer or want to save later

In action:

Note. The tool automatically enables suitable snapping configurations. However, if you want to be sure that QGIS snapped onto the right point feature / vertex point, you can take a look at the attribute table of the resulting layer and compare the coordinates of the applied centroid with the coordinates of the point you desired to utilize.

Intersect lines

1. Use the QGIS selection tools to select two line features, one line feature and 2 point feature or 4 point features:

• CompoundCurves can be used as line input too. In this case, the curve is extrapolated into a circle
• If 4 points are used as the input, the tool will calculate all possible combinations and ask which intersection point is wanted
• If your line layer has MultiLineString type of features, consider using Explode Lines tool first

2. Click Intersect lines button.

3. If there are multiple intersections points (if points and/or curves were used), select which intersection point to keep.

4. Select already existing file (e.g. geopackage) into which you wish to store the obtained result point.

• The coordinate reference system of the file must match with the coordinate reference system of the active layer!
• You can leave this file path also empty if you only need a QGIS temporary layer or want to save later

In action:

Displace line

1. Make sure that you have a line layer active in the Layers panel.
2. Click Displace line button -> the panel opens up into the right side of the QGIS.
3. In the panel, insert a value determining the distance you wish to move the line feature orthogonally. Press Enter.

• Give the displacement distance in coordinate reference system units (e.g. for EPG:3067 in meters)
• You can insert negative values too. Negative "distances" might be needed in situations where user has given the positive displacement distance and the resulting line feature has appeared to the "wrong side" of the original line feature. In other words, by replacing the displacement distance value with its opposite number, the displaced line feature will be mirrowed to the other side of the original line feature

4. Click any line feature visible on the map canvas that you wish to displace.
5. Answer to the question the tool asks from you via a pop-up window.

In action:

Note. In QGIS, a temporary scratch file can easily be exported and made permanent.

Explode polygon

1. Make sure that you have a polygon layer active in the Layers panel.
2. Utilize QGIS's selection tools to select the feature(s) you wish to explode (from the currently active layer):

• It is possible to select all the features in the layer, too!

3.Click Explode polygon button.

In action:

Note. In QGIS, a temporary scratch file can easily be exported and made permanent.

Explode line(s)

1. Make sure that you have a line layer active in the Layers panel.
2. Utilize QGIS's selection tools to select the feature(s) you wish to explode (from the currently active layer):

• It is possible to select all the features in the layer, too!

3. Click Explode line(s) button. The tool will give both line segments and points as a result.

In action:

Note. In QGIS, a temporary scratch file can easily be exported and made permanent.

Explode line(s) to points

1. Make sure that you have a line layer active in the Layers panel.
2. Utilize QGIS's selection tools to select the feature(s) you wish to explode (from the currently active layer):

• It is possible to select all the features in the layer, too!

3.Click Explode line(s) to points button.

In action:

Note. In QGIS, a temporary scratch file can easily be exported and made permanent.

Split line

1. Make sure that you have a line layer active in the Layers panel.
2. Click Split line button -> the panel opens up into the right side of the QGIS.
3. In the panel, insert a value determining into how many equally long pieces you wish the selected line feature to split. Press Enter.
4. Click the line feature you wish to split.

In action:

Note. In QGIS, a temporary scratch file can easily be exported and made permanent.

Development

Refer to development for developing this QGIS3 plugin.

License

This plugin is licenced with GNU General Public License, version 3. See LICENSE for more information.