006] Global Mapper - Creating Buffer Lines (Create Buffer)

Today, we will learn how to create Buffer Lines, which establish a range of a specific distance based on points, lines, or areas (polygons).

We will proceed by loading the workspace from our previous session.

1. Cleaning Up the Workspace

First, let's delete the unnecessary layers to keep our workspace clean.

1. In the Control Center, select both the "Line" layer and the "Viewshed Analysis" layer while holding down the Ctrl key.

2. Click the Close Layer (X icon) at the top right of the Control Center to delete them. (Alternatively, you can simply press the Delete key after selection).

Now your screen should look like the one below, with only the base terrain remaining.

2. Loading Satellite Imagery (Review)

Before we draw buffer lines, let's review how to load satellite imagery for better context. We will load imagery of a similar size to our current terrain.

1. Select the Connect to Online Data icon (the globe icon) from the toolbar.

UI Text from Image:

• Connect to Online Data: Connect to mapping data from numerous built-in and user-supplied sources.

2. When the Online Data window opens:

   • Select IMAGERY -> World Imagery.

   • Click Draw Box... to select the specific area for download.

UI Text from Image:

• Popular Sources: World Imagery

• Action: Click Draw Box...

3. In the "Drag a Box to Select Export Bounds" window, draw a square covering the desired area and click OK.

3. Once back in the main data source window, click Connect.

Now, the World Imagery layer has been added to the Control Center, and the satellite imagery is displayed on the main screen.

3. Drawing a Polygon (Area Feature)

Now, let's draw a polygon to serve as the basis for our buffer.

1. Right-click on the main screen.

2. Select Create Area/Polygon Features -> Create New Area Feature. The mouse cursor will change.

3. Click points 1 through 7 (as shown below) with the left mouse button.

4. Right-click at the last point to complete the polygon.

5. The Modify Feature Info window will appear.

6. Enter "Boundary" (or '구역계' in Korean) in the Feature Layer field and click OK.

The "Boundary" layer is now added, and you can see the polygon on the main screen.

4. Creating Buffer Lines

Now, let's add the buffer lines.

1. Select the polygon you just drew on the main screen.

2. Right-click and select Create Area/Polygon Features -> BUFFER - Create Buffers Around Selected Feature(s).

3. The Buffer Area Creation Setup window will appear. Configure the settings as follows:
   

   • Feature Layer: Enter "Buffer Zone" (버퍼존).

   • Number of Buffer Zones for Each Feature: 4 (This creates 4 concentric lines).

   • Buffer Distance: 500 Meters.

   • (Note: This means 4 buffer lines will be created at 500m intervals).

4. Click OK.

UI Text from Image:

• Feature Layer: 버퍼존 (Buffer Zone)

• Number of Buffer Zones: 4

• Fixed Distance: 500 Meters

• Action: Click OK

The buffer zone layer is created, and the buffer lines are drawn on the screen.

5. Adjusting Styles (Transparency and Borders)

In recent Global Mapper updates, newly created polygons are often filled with an arbitrary opaque color by default. This can hide the layers underneath (like our satellite imagery), which is inconvenient. Let's make the buffer fill transparent and change the border style.

1. In the Control Center, right-click the "Buffer Zone" layer and select Options....

2. When the Vector Options window appears:

   • Go to the Area Styles Tab.

   • Select Use Same Style for All Features.

   • Click Select Style....

3. In the Select Area Style window:

   • Fill Pattern: Select No Fill (This removes the background color).

   • Border Style: Select Dot (To display as dotted lines).

   • Color: Choose a bright color (like Yellow) for high visibility.

   • Width: Set to 3 Pixels to make it stand out.

   • Click OK.

UI Text from Image:

• Fill Pattern: No Fill

• Border Style: Dot

• Width: 3 Pixels

• Action: Click OK

4. Return to the Vector Options window and click Apply or OK.

Now, the buffer lines are clearly drawn as yellow dotted lines, allowing the satellite imagery to show through perfectly!

What we've covered today is the most basic method. You can explore many more options in the Buffer Area Creation Setup window to generate various types of buffers for your professional GIS needs.

That's all for today!