To show how this works, see the example below in which a forest cover ArcGrid ASCII file is vectorized into a polygon vector layer at 10% cover interval.
- Start Global Mapper. Load in a grid layer e.g. Cov.asc.
- Select ALT+C.
The Overlay Control Center is displayed.
- In the Overlay Control Center, mouse right click on the grid layer.
A pop up menu appears.
- Choose Create Area Features from Equal Values in Selected Layer.
The Setup Equal Value Area Creation dialog box appears.
- Optional. Change the Layer Description, Value Attribute Name, or Area Classification.
- In the Maximum Match Distance field, type in a value e.g. 0.05.
Note: The example grid layer cell values are actually in %, even though the screenshot shows meters. It's just that Global Mapper assumes all grid layers are elevation related layers.
- Click OK.
The vector polygons are generated.