# Measure

This page describes generic concepts on 3D Measurements, how to measure and the results obtained.

Main Toolbar > Measure

Tabs > Mapping > 1st View Side Toolbar > Measure icon

## Measure Techniques

### 3D Reference

A 3D Measurement requires a 3D Reference.

The following references can be used to measure a 3D coordinate for a 3D Measurement:

- Point cloud data
- 3D vector data
- Digital Elevation Model
- Horizontal and Vertical Reference Planes defined by Vector Data Overlays
- Ground Height defined by Camera Height
- Reference Ground Height
- Forward intersection

### Default 3D Measurement Technique

The default “3D Measurement” Measure Technique combines all supported single-click coordinate measurement techniques and returns the result of the first working technique. The Forward Intersection measurement technique, Point Cloud Flat Surface Intersection, and Point Cloud Ridges and Corners are excluded from this default 3D Measurement technique. The order of measurement technique that is used is the following:

- Point Cloud Closest Point
- Mesh Intersection
- DEM Intersection
- Reference Planes Intersection
- Ground Surface Intersection

### Preferences

Measure technique and options are set via the Measure Preferences, see

Preferences of 3D Hover and Measurements.

## Measure Functions

The measure sidebar provides access to Manual and Semi-Automated measurements.

When selecting a Measurement Function, Manual measurements are highlighted in Blue, and Semi-Automated measurements are in Orange.

### Manual Measurements

Manual 3D Measurement Functions

Manual 3D Measurements can use any measurement technique.

When using a Point Cloud Meaure Technique, only rendered point cloud points will be used. What you see is what you get. Toggling the visibility of the point cloud datasets, point cloud dataset classifications, point cloud selection, or point cloud legend query settings can be used to adjust the rendered point cloud points and impact the Manual 3D measurement.

For more information about specific Measurement Techniques available for Manual Measurements.

### Semi-Automated Measurements

Semi-Automated 3D Measurement Functions

Semi-automated 3D Measurements operate on the point cloud points of the Primary Point Cloud Dataset only. Point cloud points do not require to be rendered to be used.

Additionally, point cloud dataset classification and point cloud selection can be taken into account to filter the point cloud points used by feature detection of semi-automated measurements. The filtered points can still be rendered to be ignored by feature detection.

## How to measure

### Measure and edit measurement

Once a measure function is activated, the appearance of the cursor indicates a coordinate can be added, replaced, removed, or inserted :

- Left click elsewhere :
- ongoing measurement: add the new coordinate to ongoing measurement according to the 3D Hover preferences.
- completed measurement: clear measurement and restart measurement.

- Left click-and-drag elsewhere : Map 3D navigation.
- Left click-and-drag measured coordinate: move coordinate, replace according to 3D Hover preferences.
- Left click measured segment: insert coordinate to segment.
- Right click measured coordinate: delete coordinate.
- Right click-and-drag elsewhere : Map 3D navigation.

### Stop measurement

Most measure functions do have a well-known number of coordinates. These measurements are ended automatically once the number of expected coordinates is measured.

Only for the “Free Line” and “Free Area” measure functions, the number of coordinates is not defined beforehand. Finishing the free line and area measurement is slightly different depending on the measure mode :

- Point Cloud or Reference Plane Intersection:

Measurements can be ended by (a) a double left click or (b) a right click > “Stop measurement” once, respectively, at least 1 or 2 coordinates are measured. The end coordinate will be added as the last measurement coordinate. - Forward Intersection:

Measurements are completed as soon, respectively, at least 2 or 3 coordinates are measured and both viewers have the same amount of measurements. Double left-click or the right-click context menu cannot be used to finish the measurement.

### Use results

- Left click value

A single click on a displayed result value copies the value only to the clipboard, ready to paste it as an attribute value via the Object Inspector or in any other document. - “Copy to clipboard”

Copy all displayed results (tab separated) to the clipboard, ready to paste into a spreadsheet. - “Copy to Feature”

Copy measurement to the recordable dataset. This button is only enabled if the spatial object type (point, line, area) of the completed measurement and recordable dataset are the same.

### Objects

- Edit: Insert, replace, or delete vertices of the selected Focus Object.
- Update: Apply the edits to the Focus Objects.
- Delete: Remove the selected object(s). Multiple objects can be deleted at once.

## Results

### Absolute (coordinate) measurements

Absolute coordinates (xyz) are expressed in the Map coordinate system. If no vertical Map CRS is set, the Z of the used data source will be retained.

### Relative measurements

Relative Measurements do NOT depend on the Map CRS.

All relative measurements (distance, line, area, volume) fall back to the geocentric coordinate reference system, see ECEF.

### Distance

- XYZ: 3D length of straight line between start and end point.
- XY: 2D length of straight line between start and end point, or length of the projected 3D distance with Z = 0.
- Z: absolute difference in Z between start and end point of straight line.
- Slope: The inclination with the horizontal reference plane expressed in % (100% = 45deg), also called grade.
- Slant: The inclination with the vertical reference plane expressed in degrees.

### Length

- XYZ : Summed 3D length of each line segment as distance XYZ.
- XY : Summed 2D length of each line segment as distance XY.
- Z : Summed absolute difference in Z of each line segment as distance Z.

### Catenary

- Distance over curve : 3D length over catenary curve.
- Clearance : Minimum height above ground. The Ground height is calculated by the Z from the photo position minus the Heigt from the camera above the ground.
- Span : Distance XY.

### Area

- XYZ : Area projected on best fit 3D plane through all measured vertices. This technique expects all vertices to be measured in approximately a single 3D plane.
- XY : 2D area, or area of projected 3D area with Z = 0.