Range Rings - hiding area boundary
Niels
Global Mapper User
Hi,
I am trying to draw range rings for different types of aircraft but have a problem as soon as the range goes beyond the point where it is no longer a closed ring.
At that point a straight, horizontal line is drawn which I cannot hide or remove.
For example, creating a range ring of 2000 nautical miles from New York works fine. Create a 3000 nautical mile ring and the top edge of the area is rendered as a straight line that I would like to hide.
I also cannot find a way to change the range of an existing range ring. Even if I change the range attribute of the feature info to a different distance, it has no effect on the rendering.
Many thanks for any help with this!
Niels
I am trying to draw range rings for different types of aircraft but have a problem as soon as the range goes beyond the point where it is no longer a closed ring.
At that point a straight, horizontal line is drawn which I cannot hide or remove.
For example, creating a range ring of 2000 nautical miles from New York works fine. Create a 3000 nautical mile ring and the top edge of the area is rendered as a straight line that I would like to hide.
I also cannot find a way to change the range of an existing range ring. Even if I change the range attribute of the feature info to a different distance, it has no effect on the rendering.
Many thanks for any help with this!
Niels
Comments
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Which version of GM are you using? It looks like it's working correctly in the latest V11 Beta.
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I am using version 10.00
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Download the update (10.02), as it seems to be working correctly there too.
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Did that, am now running version 10.02 but the horizontal line is still there for range rings that are not closed rings.
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It sounds like the lines are being clamped, rather than clipped. If you zoom out (home), do you see the whole ring? If so, I wonder if it's a graphics card driver issue. No ideas other than that, sorry.
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What projection do you have setup on the Projection tab of the Configuration dialog? I'm thinking that perhaps your projection is discontinuous at the poles, as most are. If you switch to something like Polar Stereographic for rings that go around the poles I think your display will be better.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com -
Thanks for the suggestion Mike, but for our purposes we need to use geographical projection (Lat/Long). When presenting aircraft range maps on a website the industry standard is this projection. Please have a look here to see what we are trying to accomplish:
Bombardier - Learjet 85 - Range Map
Try clicking on the different cities. We want this to be available for about 50 aircraft types and 20 cities...
The horizontal line at the top of the area is actually somewhat misleading, since the true range reaches outside (North) of there, but that's not the impression one gets with the line being rendered there.
I am hoping there is a way to remove it...
Thanks,
Niels
PS: If I select "Show area and line vertices", then the result is correct, but the vertices of the world admin boundaries are shown as well and the line thickness of the vertices is to great (where can that be changed?). I suspect that even if I can make the vertices look nice there will be now way to differentiate them from the country boundaries, or to turn off vertices for a particular type of area... -
Niels,
I took a look at your particular case and found that the real problem is when the data crosses the anti-meridian (+180/-180) as the projection is discontinuous there. What I would suggest is selecting your range ring area with the problem, then right-clicking and selecting to create a line feature from the area. What you can then do is edit that line and split it into pieces where it crosses the anti-meridian at both sides, then delete the remaining segment that goes across the entire map due to the ATM cross.
Let me know if I can be of further assistance.
Thanks,
Mike
Global Mapper Support
support@globalmapper.com
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