Measurement Tools
Gradient / Slope
The Gradient tool measures the slope between two points on your site. Click the start point and then the end point, and SiteView calculates the gradient as a percentage, angle in degrees, and ratio — with a colour-coded line on the map that tells you at a glance whether the slope is gentle, moderate, or steep.
![[Screenshot: A gradient measurement between two points on the SiteView 3D globe with a colour-coded line (green) and results panel showing slope percentage, angle, ratio, and bearing]](/images/placeholder.png)
Activating the Tool
Open the Measurements tab in the site detail floating panel and click the Gradient icon, or press G on your keyboard. The cursor changes to a crosshair.
Drawing the Measurement
The Gradient tool uses two points:
- First click — places the start point
- Second click — places the end point and completes the measurement
As you move the mouse after placing the first point, a live preview line follows the cursor showing the gradient in real time. This lets you explore the slope across different directions before committing to the second point.
Results
Once both points are placed, the results panel displays:
| Result | Description |
|---|---|
| Slope percentage | The gradient expressed as a percentage (rise / run x 100). Positive values indicate uphill from start to end; negative values indicate downhill |
| Angle | The slope angle in degrees from horizontal |
| Ratio | The gradient as a ratio (e.g., 1:20 means 1 metre of rise over 20 metres of run) |
| Bearing | The compass bearing from the start point to the end point |
| Horizontal distance | The flat (plan-view) distance between the two points |
| Elevation change | The vertical difference between the start and end points |
ℹ️ Did you know?
The three slope formats — percentage, degrees, and ratio — all describe the same gradient in different ways. Construction specifications in Australia and New Zealand typically reference gradients as percentages (e.g., "maximum 5% grade") or ratios (e.g., "1:4 batter slope"). All three are displayed so you can match whichever format your specification uses.
Colour-Coded Line
The measurement line on the map is colour-coded to indicate the severity of the slope:
| Colour | Slope Range | Interpretation |
|---|---|---|
| Green | 0% to 5% | Gentle slope — suitable for most vehicular traffic, footpaths, and drainage falls |
| Amber | 5% to 15% | Moderate slope — common for driveways, ramps, and minor embankments |
| Red | Above 15% | Steep slope — typical of batter slopes, retaining wall zones, and difficult terrain |
The colour changes smoothly across the thresholds, giving you an immediate visual indicator without needing to read the numbers.
💡 Tip
Use the colour coding for quick visual scanning. If you are checking multiple slopes across a site — such as verifying drainage falls on a car park — the green/amber/red line colours let you spot problem areas at a glance before reading the detailed numbers.
Practical Uses
- Drainage falls — verify that surfaces slope at the minimum required gradient (typically 1-2%) towards drainage points
- Ramp grades — check that vehicle and pedestrian ramps comply with maximum gradient requirements
- Batter slopes — measure the slope of embankments and verify they match the specified batter angle (e.g., 1:2 or 1:4)
- Road cross-fall — measure the cross-fall of a road surface from centreline to kerb
- Site access — check that temporary access roads do not exceed safe gradient limits for construction vehicles
Elevation Data
Like other elevation-dependent tools, the Gradient tool reads elevation from the best available source:
- Processed DEM — if a drone survey DEM covers both points, the gradient is calculated from the DEM elevations
- World terrain — if no DEM is available, the CesiumJS world terrain dataset provides approximate elevations
For accurate gradient checks — particularly for drainage falls and specification compliance — always ensure you have a processed DEM covering the area being measured.
⚠️ Watch out!
A 1% drainage fall over a short distance (e.g., 5 metres) represents only a 50mm elevation difference. World terrain data does not have the resolution to reliably detect such small differences. Use a processed DEM for any gradient check where the expected slope is below 5%.
Saving the Measurement
Click Save to record the gradient measurement. Add a category (e.g., Drainage, Access, Earthworks), notes describing what you were checking and the specification reference, and photos. Saved gradient measurements appear in the Measurements tab and can be re-displayed with their colour-coded line.
What's Next?
- Height Measurement — measure the vertical distance between two points
- Elevation Profile — see the full elevation chart along a drawn line
- Measurement Tools Overview — return to the full list of measurement tools