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Creating and Editing Paths in Google Earth

New Zealand Rail Maps
Mapping New Zealand's rail lines

Creating and Editing Paths in Google Earth

Creating and Editing Paths

In all of the maps in the NZ Rail Maps site, I use paths to show routes. The path is a sequence of individual points. I can place the points on the map at any place, and Google Earth automatically draws the path between successive points.

Therefore the creation of a path simply involves adding the points in the right places. You can edit a path by dragging points to new places, adding additional points, or deleting points. The line that Google Earth draws between the points can have its colour, width and opacity changed.

Create a Path

Give your new path a name, and if you wish, a description. Leave this box open for the moment. Just drag it to somewhere on the screen where it won't get in the way of the map.

Now you need to decide where to put the first point of your path. In this tutorial, I refer to this first point as the "origin". The last point I refer to as the "end". I'll explain these terms a little bit more shortly. This just has some relevance to where you should put the origin point. I usually put it, in railway terms, at the lowest milepeg on the rail line I am working on, and work in the direction that  the mileage runs.

To start drawing, just move the crosshairs to where the origin should go, and click. A green point should now be visible on the map. To extend the path, just move to a new position and then click again. As you add each new point, a  line is automatically drawn between successive points. A curve is just a lot of points that are close together.

Below you can see a yellow line that I've created, with its points in red (except for the active point, which is blue. I'll explain that more shortly). Each time you add a new point, it is inserted after the active point, and the new point you have added becomes the active point (blue).

To finish editing the path, click the OK button in the "New Path" box that opened when you added the path. You should now see your new path with this icon next to it, something like this (the caption will be whatever you named it); .
Note the path icon; it is three points arranged in a triangle with lines joining them.

Edit a Path

You can edit an existing path at any time. Examples of what kind of changes you might want to do could be:
Firstly you need to open the path for editing:
This will open a box like the "New Path" one you saw above except it is now titled "Edit Path". Otherwise it is exactly the same.
At the same time, the path will change on the map so that all of the individual points can be seen.

Google Earth stores the points of your path in a definite order. The origin is always the first point in a path. The end point is the last point on the path (at the opposite end from the origin). (more of this shortly)

Dragging points
You can drag any point in a path to a new location on the map. The line is automatically redrawn.

Adding points to the end of the path
You can add a new point after the end of the path at any time. You need to first select the end point (it will change colour to blue) and then click at the new location on the map.

New points can only be added to the end. You cannot extend the path at its origin this way. (There is however another way of doing this which I will describe shortly).

Adding new points between existing points
You can insert new points between existing points in the path. In relation to the path's origin, you are inserting these points "after" the active point. Select an existing point on the map (it will change to blue). Then click on the map where you want your new point. The path is automatically redrawn to include the new point.

Deleting points
You can select any point on the path and delete it. When a point is active (blue), press Delete on the keyboard to delete it (or click the right mouse button). The path is automatically redrawn.

Extending the line at the origin or changing the origin
The origin is always the first point of any line. Because you can only insert new points after an existing point, Google Earth doesn't let you add a point before the origin to make a new origin.

However, you can drag the origin to a new place on the map, and then "fill in" the path between the origin and the next point on the line, by adding new points after the origin.

The only way of changing the origin is that by deleting it, the next point in the line will become the origin.

Close the Edit Path box by clicking OK when you have finished editing the path.

If you have got this far and are getting the hang of creating and editing paths, then you are doing really well.

Click here to go back to the Tutorials menu on the website to see if there are any more Google Earth tutorials for you to try.

New Zealand Rail Maps: Google Maps / Google Earth Tutorials

Patrick Dunford.


Last updated 14 January 2009.