You can use the Location Tool and the Line Tool to measure Nearmap's 3D imagery. This articles explains how and covers:


Measurement Accuracy

The greatest source of error when measuring distances less than approximately three km is your ability to select the start and end points correctly.

The 3D scene has the following spatial accuracy specifications: Horizontal - 11" or 28cm RMSEr, Vertical - 16" or 40cm RMSEz

Assuming an object is well constructed as described above and the correct start and end point for a desired measurement can be chosen, measurement should be within 40cm.



Watch the video: MapBrowser - 3D Viewer & 3D Export


Line Tool

You can measure lines in 3D using the Line tool.

You can also measure Lines and Areas using Nearmap's Oblique imagery.

  1. To access the Line tool for 3D imagery go to the location you want, then switch to 3D view by using the compass tool.

  2. When you are in 3D view, click the Line tool.


Measuring Lines

  1. Zoom into the property you want to measure, then draw a line along the slope you want to measure.

  2. When you access the Line tool you will see a disk that aligns to the surface it is on. This can help you decide where to start and end the line you are measuring.



  3. Left-click to start the line, double-click to end the line.



The measurements include:

  • Line length - the distance between the both ends of the line in meters, kilometers, feet, yards, miles, or nautical miles.
  • Pitch - the angle of the line relative to the horizon in degrees or rise/run ratio.
  • Relative height - the difference in height between both ends of the line in meters, kilometers, feet, yards, miles, or nautical miles.

Display options:

  • You can choose the colour and brightness of the line.
  • By default the units are displayed on the line itself. You can opt to hide these by unchecking the Line box in the Feature Layer panel


Once you are done, you can zoom in and out, pan, and tilt, and the line will still be there.


Area Tool

Use the Area tool to measure the area, perimeter and pitch of a surface on Nearmap’s 3D imagery.

  1. To access the Area tool, go to the location you want, then use the compass tool to switch to 3D view.
  2. When you are in 3D view, click the Area tool.


  3. Draw out a polygon by single-clicking on each desired vertex.
    When you access the area tool you will see a disk that snaps to the surface nearest to your cursor. Maintain the angle of this disc to ensure you draw the polygon on the one plane.
  4. To close the polygon, hover over the start of your polygon until you see a small circle, then left-click.


  • You can see the area, perimeter and pitch of the polygon.
  • Use the dropdown against each measurement to change its units.
  • Use the color tools to adjust the polygon’s color settings.
  • By default the units are displayed on the polygon itself. You can opt to hide these by unchecking the Area, Line and/or Texture boxes in the Feature Layer panel


Check your polygon

Check the area you have drawn is on the one plane

The area may look fine from your original viewpoint, but because the area tool snaps to the nearest surface, it may accidentally pick up an object, such as a tree or another structure.

  1. Rotate the imagery to ensure the polygon is tracing the surface you want
  2. Drag and drop a vertex to adjust, if needed.




Drawing multiple faces

For best results draw one plane at a time. Drawing several planes at once may give you unpredictable results.

Drawing both faces of pitched structure
Note the irregular surface produced		Drawing each face separately
Each face is clean and one its own plane.

      

Ensure the area you draw makes sense

If you draw self-intersecting sides, you will get an error.


Measuring in 3D FAQs

Do viewing and measuring 3D content consume my data usage?

Viewing and measuring 3D content do not count towards your standard imagery data allowance.


Will there be other measurement tools for 3D imagery?

The 3D tool set will be expanded over time. We would love to hear what tools you would like included in the future.


How do I know if my measurement line end point is at the spot I meant it to be at?

Lines will begin and end on the surface of the 3D mesh, when using the line tool a disc is used as a guide to the surface you are hovering over. This disc will reflect the surface slope and angles as you move over them and this can help you decide where to start and end your line.

Changing the camera position may also help you validate if you put the point where you wanted to put it, though at some angles seeing the line in front of the building may be confusing.


Why is the measurement different to the equivalent one I made on the Oblique map?

The most difficult part of measuring using either method is accurately picking the top and bottom of the object due to shadows, obstructed views and the limits of resolution. With practice behavior becomes more consistent, and in tests of measuring with both 3D and oblique images, results are consistently within about 1 meter of each other.


Which measurement is more accurate, 3D or Oblique?

The accuracy of the measurement tool is the same, so this will largely come down to how well the object in question has been resolved through either method and will vary from object to object. In practice the method that allows you to choose the top and bottom most clearly will likely result in the most accurate measurement.


Are my lines and measurements saved in projects?

Yes.


What geoid models are used with Nearmap's 3D imagery?

AU: AHD (AusGeoid09)
US: EGM2008 
Canada: CGVD2013