problem combining polygons

JSL

I had a circular polygon that I split, then added terrain data to each half. However, when I tried to combine the two halves, one disappeared. I checked for invalid areas, but there weren't any. Any idea why one half would disappear upon combining?

disappearing polygons.zip

Polygons before combining:

Checking for invalid areas:

After combining:

JeffH@BMG

Hi JSL,

I can reproduce what you're seeing. It's a bit of a mystery, as the two polygons do indeed intersect at their boundaries, so they should combine correctly. Unfortunately, I can see that when we combine them internally, no result is generated, so we keep the original area feature and move on, which is what you're seeing.

I'm not sure what version of Global Mapper that you're using, but it must be relatively recent. If so, you should see a "Use legacy method" checkbox on the "Select Combine Options" dialog. This uses the original Combine code, which we replaced with a much faster implementation, but kept around for situations like this. When I checked "Use legacy method", the polygons combine as expected.

In the meantime, I created a new issue (GM-14338), so we can take a closer look.

Thanks for reporting this.

~Jeff

JeffH@BMG

Sorry, the issue is actually GM-15080, just for the record.

~Jeff