3.0 Possible problem with polyconic charts

[wdkester]

I have loaded (only) District 9 charts. A lot, but not all, are polyconic. The attached file, Screen 1, shows us zoomed in on Grand Marais MN. If I stay at this level of zoom I can pan around with no problems. If I zoom in one more level, the bottom of the screen disappears, as seen in screen 2. The second mercator chart, shown in the chart bar, has a scale of 60000, the second polyconic 120000.

I have opengl turned on. It seems to do a much better job of rendering, especially when panning,

[HappySeagull]

WD,
try turning "Quilting" off. Polyconic and Mercator don't play well together. There's something in the manual about this..

[wdkester]

Originally Posted by HappySeagull

WD,
try turning "Quilting" off. Polyconic and Mercator don't play well together. There's something in the manual about this..

Quilting is working well in screen 1, when I zoom in there should be no temptation to quilt the mercator chart as we are looking at a smaller area on the polyconic chart. I am thinking about deleting the mercator chart as I don't think it's necessary.

[HappySeagull]

WD, I get similar oddness but open GL is off. For me, it's some kind of residual effect caused by zooming in and out...these apparently aren't Polyconic though...




it should stay like this...



I just remove the smallscale chart from quilting with a right click but I think something odd IS going on.

[HappySeagull]

added: first noticed in the 2.6.1718 beta which I was using at the time (and she worked consistently well otherwise! per my simple usage 12-14 hours at a stretch) but the screenshots are from 3.0.
Both Portable versions.

[cagney]

Originally Posted by wdkester

Quilting is working well in screen 1, when I zoom in there should be no temptation to quilt the mercator chart as we are looking at a smaller area on the polyconic chart. I am thinking about deleting the mercator chart as I don't think it's necessary.

There seems to be a problem, in the situation with a single large scale chart against the background of a small scale chart, in a transition, when zooming in. I can recreate the black area you described in many other places quilting polyconics only. It appears just before the large scale chart takes over the full screen.

Thomas

[wdkester]

I deleted the mercator and still have the problem. I tried three different harbors along the coast with the same results.

[HappySeagull]

WD, there's always the hack-the-chart solution ! simply change the "Polyconic" in the header to "Mercator" and save with a new name so as not to overwrite originals. A bunch of waypoints as comparison points will show you if the position error induced is important . Most of my Poly's are hacked this way and quilt well.

[wdkester]

The "Black Space Polyconic Chart Bug" is more than annoying. In flyspray it is marked PRI=Low. I think it ought to be high. It happens in every instance I have tried. You can pan beyond the edge of any chart and the largest scale poly chart (if there is one) is not quilted.

I haven't done this on the water, but, it is possible to place the boat Icon, using a right click, in the black space. To me this means that if I were coming out of Knife River, heading South, I could sail into the blackness. Scary.

I used Opencpn (mostly 2.5) on a trip that started North of Baltimore and ended in Guatemala. I thought it performed very well. The earlier versions had stability problems, 2.5 didn't. That said, I don't think I will use Ocpn raster charts, in Lake Superior, until the bug is fixed. I can use the vector charts as long as I stay in US waters. The reason that I want to use raster charts is the Canadian raster charts are much cheaper for my sailing area, $150 vs $500.