[023] Global Mapper - How to Close Gaps Between Adjacent Features in Vector Layers

Today, we will explore the final item in the layer context menu that applies to all vector layers: "Close Gaps Between Adjacent Features..."

Understanding the Purpose

In digital mapping projects, especially when dealing with cadastral maps or engineering blueprints, you might encounter tiny, unintended gaps between lines or polygons. The "Close Gaps Between Adjacent Features" function is designed to eliminate these gaps by aligning the positions of vertices (vertex snapping).

While this isn't a tool you'll use every single day, it is incredibly efficient for shortening the time spent manually zooming in and out to align boundary lines or design elements.

Step-by-Step Guide

1. Prepare Your Layers

First, open the project file we worked on in the previous lesson. In the Control Center, make sure to activate both the 'Line' (선) and 'Area' (면) layers. These will be our target layers for today's demonstration.

2. Access the Function

Right-click on the selected layers in the Control Center to bring up the context menu. Navigate down and select "Close Gaps Between Adjacent Features..."

3. Select Target Layers

A "Select Layers" dialog box will appear. Here, you need to confirm which layers you want the operation to apply to. Select both the 'Line' and 'Area' layers and click OK.

4. Specify Distance and Snapping Rules

Next, the "Specify Distance" window will pop up. This is a crucial step where you define how the snapping occurs:

• Gap Distance: The number you enter represents the maximum distance between vertices. Any vertices within this specified range will be snapped together to close the gap.
• Process each layer separate from the others:
• If checked: The software only analyzes and snaps vertices within the same layer.
• If unchecked: The software analyzes distances between vertices across different layers and snaps them together.

5. Analyzing the Map Scale

Before confirming, let's look at the map scale. In this example, looking at the scale bar, the distance between the vertices of our features is several dozen meters.

We will enter 60m as our threshold and click OK.

The Result

As you can see, the shape of the features has changed. The vertices moved to meet each other, effectively closing the gap.

Important Considerations

The reason this tool isn't used for every situation is that the results can sometimes be unpredictable. The function doesn't allow you to set a "base" or "reference" layer that stays fixed while other layers move. Instead, it simply moves all relevant vertices to a calculated meeting point. Use this tool when you have many small gaps and need a quick fix, but always review the results to ensure the geometry still meets your project requirements.

Conclusion

This concludes our walkthrough of the layer-specific context menus in Global Mapper. Understanding how these menus change based on the characteristics of the data within the layer will make your project management much more intuitive.

That’s all for today! Happy mapping!