Find distance between 2 point along a line
So I have a centerline road network.
I would like to start at a point and go a distance of 20km and create another point or select the line up to the 20km.
Is this something that is doable in GM?
Global Mapper User
Here's how I would create a point that's 20km from another point:
The first thing you would need to do is make sure that your two points lie on only one line, so you may need to combine two or more lines. The best thing to do would be to make a copy of the lines and combine them, so you can leave your original lines intact.
An easy way to create two or more points on an existing line is to select the line then right click and choose Analysis/Measurement -> PATH PROFILE - Generate Path Along Line(s).
You'll then see a profile of your line (you have to have a terrain layer in the workspace to do this). As you move the cursor, you'll see an X travel along the line (where the red arrow is pointing in the below image). You can stop where you want your first point to be and right click, then choose Create Point Feature at Cursor Location:
There's two ways to get the second point. The first way would be to move the cursor along the line to where you think 20 km would be, and create another point. However, there;s another more precise way that's a little more detailed.
First, you would create a circular buffer around the first point with a by selecting the point, then choosing Advanced Feature Creation Options -> BUFFER: Create buffers around selected features.
In the dialog box that appears, set Fixed Distance to be 20km, and make sure that the option to "Create rectangular buffer" at the bottom of the dialog box is NOT checked:
You'll end up with a circular area feature in the User Created Features layer that has a radius of 20km:
The next thing to do would be to make sure the buffer is selected, then create a line from it by right clicking and choosing Advanced Feature Creation Options -> Create Line Feature from Selected Area Feature. This will create a buffer outline line feature which will end up in the User Created Features layer as well. You can split the User Created Features layer by Feature Type so the outline is in its own layer.
Next, select both your original line and the buffer outline, and right click and choose Vertex Editing->Insert Vertices and/or Split at Intersections of Selected Features. In the dialog box that appears, choose "Insert vertices at intersections only":
It will ask if you want to create point features at the intersections, and choose Yes. This will create a new point exactly 20 km from your original point: