1. Mick West

    Mick West Administrator Staff Member



    I wrote a flat vs. globe route simulator over the weekend. It shows the shortest route between two points on a globe, a flat earth, and an standard map. The lengths of each route are calculated for the globe and the flat earth.

    (Note: does not work on mobile devices, works best with Chrome)
    Last edited: May 9, 2017
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  2. Amber Robot

    Amber Robot Member

    What kind of projection are you calling "standard"? Mercator? What does that route mean, if anything?
  3. Mick West

    Mick West Administrator Staff Member

    It's equirectangular, it's the map you see there.

    The route shown by the yellow line is similar to a rhumb line course, which is a reasonable route for short distance navigation. You just follow a fixed compass heading. It's longer than a great circle, but the great circle route needs constant changes to compass heading.

    A straight line on a Mercator map is a true rhumb line, but you can't get the whole world onto a Mercator map.

    The Mercator map is essentially evidence of the globularity of the world, as if the world were flat the map would shrink at the bottom, and not expand.
    Last edited: May 8, 2017
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  4. Mick West

    Mick West Administrator Staff Member

    This page has good explanations and illustrations of the differences between a rhumb line on a Mercator vs. equirectangular (same as Equidistant cylindrical) maps.
    http://www.progonos.com/furuti/MapProj/Normal/CartProp/Rhumb/rhumb.html 20170508-172639-hw9qr.
    (Note there's 5° missing off the top and bottom of this mercator projection)

    True Rhumb lines might be a good addition to the simulator at some point. But I'm done programming for a while.
    Last edited: May 9, 2017
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  5. Amber Robot

    Amber Robot Member

    Great explanation! Thanks.
  6. Steve Ross

    Steve Ross New Member

    Hi Mike
    I tried opening the program on my PC. I have Chrome. Only the screen of the example opens and i cannot access it. Please assist.
  7. Rory

    Rory Senior Member

    Tried for first time today, using Chrome, but doesn't seem to work. Only things that responds to clicking was the sphere in the lower right, which will turn, and move up and down with arrow keys (couldn't scroll the text down, for example).
  8. deirdre

    deirdre Moderator Staff Member

    i had to open my window big enough to see all the text. Did you try grabbing the ends of the lines on the flat map?

    it's working ok for me.
    3-25-2018 10-40-10 AM.
  9. Mick West

    Mick West Administrator Staff Member

    It's certainly messed up a bit with some changes to Chrome, but it still works dragging the very ends of the lines. I put this in the appropriate thread:
    Metabunk 2018-03-25 07-55-05.

    (Note the white sections of the actual route are just straight lines joining the ends of available data, green is actual positions)
  10. Mick West

    Mick West Administrator Staff Member

    I've updated it to be a bit more forgiving when clicking on things. Also patched the issue with retina displays. And turned off the yellow line by default to simplify things.
  11. Rory

    Rory Senior Member

    Is it possible that it's a PC-chrome thing? Still doesn't seem to work on mine.
  12. Mick West

    Mick West Administrator Staff Member

    I'll look into it.
  13. Mick West

    Mick West Administrator Staff Member

    It works on a fairly clean Windows 10 with a fresh install of Chrome. So possibly a conflict with a plugin.
    Try the developer tools/Console, see if there's an error message.
    Metabunk 2018-03-26 13-21-05.
  14. Mick West

    Mick West Administrator Staff Member

    Also try running it in an incognito window.
  15. Mick West

    Mick West Administrator Staff Member

    And just to be clear, are you clicking and dragging the end points? Like:

  16. Rory

    Rory Senior Member

    Developer tools gives me the same output as you show in your window. Incognito window reveals the full text (can't scroll to the bottom in normal window).

    Both still not quite working though. Lines disappear and it's hard to find the ends.

    (Running Windows 10 on an i3 Acer s3.)
  17. Mick West

    Mick West Administrator Staff Member

    I suspect it's a WebGL issue with your graphics card. Unfortunately hard to troubleshoot.
  18. alarmour

    alarmour New Member

    I think you mean QF9 or QF10 (depending on direction) - QF8 is DFW-SYD.

    BTW - As another data point - the pages is working correctly on Ubuntu 16.04 LTS/Chromium 65.0.3325.181

    A better flight to demonstrate the totally unrealistic nature of Southern Hemisphere flights on a FE model is QF63/64 between SYD and JNB...

    Last edited by a moderator: Apr 4, 2018