Profile Tool
:::caution Last revised 2026-05-02 — not re-verified
This page has not been checked against the running system since it was
written, and predates a large part of the current product. It is scheduled
for rewrite. For anything about the API, /docs on a running server is
authoritative.
:::
The Profile Tool runs r.profile along a drawn transect line and displays the elevation (or any raster value) as an interactive chart.
Opening the tool
Click the profile toolbar button (the bar-chart icon with a circle border) to open the Profile Tool panel.
Steps
- Select a raster from the Input raster dropdown
- Optionally set a Resolution (blank = use the current region resolution)
- Click Draw Line — the cursor enters drawing mode on the map
- Click the map to add waypoints; double-click to finish the line
- Click ✓ Done when satisfied with the line
- The tool automatically submits the profile and displays the chart
Controls
| Button | Action |
|---|---|
| Draw Line | Enter waypoint drawing mode |
| ✓ Done | Finish drawing and run the profile |
| ✕ Clear | Remove the transect line and reset |
| ↺ Re-run (chart toolbar) | Re-run the profile with changed inputs |
Chart
The profile chart shows distance (metres) on the X axis and raster value on the Y axis. Hover over the chart to see exact values. Zoom with scroll and pan by dragging (Chart.js zoom plugin).
Transect line
While drawing, the transect is shown as a cyan polyline on the globe. After the profile runs it is replaced by a vertical wall curtain — semi-transparent orange fill with a bright red outline. The top edge of the wall follows the actual elevation values from the profile; the bottom is fixed below the terrain minimum. This makes the cross-section clearly visible from any viewing angle, even over complex terrain or bathymetry.
The wall is removed when you click ✕ Clear or draw a new line.
Chart–globe synchronisation
Hovering over the chart moves both the hairline on the chart and a marker dot on the 3D globe to the corresponding position along the transect. Hovering the Cesium wall updates the chart hairline in the same way.
Session persistence
The active raster selection, waypoints, resolution, and chart result are all included in the workspace autosave. When you restore a session the transect line and chart are re-drawn without re-running the module.