Get Tractrix

Getting started

Applies to Tractrix for QGIS 0.2.0~10 min

This guide takes you from nothing to a checked swept path. It uses Tractrix for QGIS, which is free and has every tool; the concepts are the same in the other products.

On this page

1. Choose a product

Table 1 Which product fits your workflow.
You work inUseStatus
QGIS, or GIS data in any projected CRSTractrix for QGISAvailable
AutoCAD drawings (DWG)Tractrix for AutoCADPreview
Revit modelsTractrix for RevitPreview
A browser, with a teamTractrix CloudPreview
Scripts, CI or your own softwaretractrix-engine CLI and APIBeta

2. Install Tractrix for QGIS

  1. Install QGIS 3.34 LTR or later (QGIS 4.x is supported).
  2. Download the plugin ZIP from the download centre.
  3. In QGIS choose Plugins → Manage and Install Plugins → Install from ZIP, select the file and press Install Plugin.
  4. Check that Processing → Toolbox now lists a Tractrix provider, and that a Tractrix menu and toolbar appeared.

If the tools do not appear, see plugin doesn't load.

3. Run your first swept path

  1. Create a project in a projected CRS in metres (for example your national grid or UTM zone). Geographic layers also work: they are computed in the local UTM zone.
  2. Create a line layer and draw the taxiway centreline in the direction of travel. The first vertex is where the tracking point starts.
  3. Optionally, create a polygon layer with the pavement outline, for the edge-margin check.
  4. Open Aircraft path simulation (taxi / group path). Set Path lines to your line layer, choose an aircraft (for example A320), set Tracking point to Cockpit follows the path, and select your pavement layer.
  5. Press Run. Envelopes, tracks, footprints and issues are added to the map.

4. Read the results

  • Envelopes: the blue swept envelope is the area the aircraft covers; the dashed clearance envelope adds the distance the standard requires.
  • Tracks: the outer main-gear tyre tracks show the track-in inside the turn.
  • Issues: a red polygon marks each problem: steering beyond the aircraft's limit, a tyre closer to the pavement edge than allowed, or an obstacle conflict. Open the attribute table to see the value, the limit and the distance along the path.
  • The Log tab of the dialog prints, per run, the maximum steering angle, exceedances, minimum edge margin and conflicts.
Tip

Open View → Panels → Temporal Controller and press play to watch the aircraft move along the path. See animation.

5. Next steps

  • Open the demo project sample_data/demo_airport.qgz from the repository and follow the walkthrough.
  • Learn what each tool does in the QGIS manual.
  • Understand the model and its limits in the methodology.