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Thread: How do I start on a map that will feature latitude and longitude?

  1. #1

    Help How do I start on a map that will feature latitude and longitude?

    I'm trying to get started on a rough world map, then scale down on smaller regions and do details. But, I'm really not sure where to start, since I want it to be a realistic map with proper scale and with lines of latitude and longitude. My problem is not so much with the scale as it is the latitude and longitude.

  2. #2
    Guild Artisan Pixie's Avatar
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    Right, here's a three to four steps procedure.. I'm aiming at simple and straight forward.

    0. Advice before the first ink

    - Don't get attached to a particular line, shape or detail of a file/layer early in the creation process - the more you can change the better.
    - Get a program that allows you to work in layers, be it in raster form (gimp, photoshop, etc) or in vector form (illustrator, inkscape, etc)
    - Plan...

    1. Actual start

    - Start with a large file. If you want to map a whole planet, the size ratio needs to be 2:1 (360 degrees E->W, 180 degress, N->S). That way, the (x,y) position of each pixel has a direct match in longitude, latitude terms - this is called an equiretangular projection.
    - Your first task is to draw a land mask. This is a solid black shape on a white background, or vice versa. As with everything from now on, it is better to have solid white in one layer (background) and the land mask (the solid black shape) in another (the rest of the layer being transparent).
    - After you have the land mask, keep ploughing (different layers, always!) - there's infinite levels of detail, you take it to where you want to

    2. Latitude, longitude, gridlines, distances...

    - Find and download these free programs: G.Projector and Google Earth.
    - G.Projector will let you upload your equiretangular map and turn it into (almost) any kind of projection. It also makes the latitude/longitude lines (it's called a graticule) if you want.
    - Google Earth will let you glue your landmask on top of the globe and measure distances in it. The Pro version will let you measure areas as well.
    - Study some geography, find images of Earth that are helpful/clear to you and keep them in a "reference folder"

    3. My personal take:

    - Before you have a beautiful map, you need to have a working map. This is a heavy duty file, with a lot (a lot!) of layers with different notes and scribbles. The art piece is another project, another file. Normally, I save my working file under a new name, delete the layers I don't need and start from there to make an actual map.

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    Guild Expert johnvanvliet's Avatar
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    - Don't get attached to a particular line, shape or detail of a file/layer early in the creation process - the more you can change the better.
    - Get a program that allows you to work in layers, be it in raster form (gimp, photoshop, etc) or in vector form (illustrator, inkscape, etc)
    that first one is GOOD!!!

    i find that about 80 to 90% of things a start i DELETE early on
    -- because ": they just do not look ?? right??? "

    layers are GREAT
    but also take a page form the 1990's
    SAVE individual parts

    back when you had a 3 gig drive and used Floppies ( 3.5 in & 5.25 in ) you SAVED to the floppy !!!!

    that is still good today

    save the different layers as separate files ( as a BACK UP!!!! )

    you can always delete them in a week or two ,but drive space is now a bit cheep

    the problem with "G.Projector"
    is it is mostly useless


    you can get near to correct using some simple tools like MMPS
    http://www.users.globalnet.co.uk/~arcus/mmps/

    a commandline tool -- it really dose a good job

    for drawing a world

    there is NO!!! BEST projection

    the poles will be a pain in the rear
    so
    start on the mid latitudes using a Mercator projection
    60 N to 60 S

    then fil in the pole areas by REMAPPING ( G.Projector can NOT do this )
    45n to 90 n and 45 s to 90 s
    to polar stereographic

    Finnish the poles

    then use "simple cylindrical " as a final projection

    now this will take a bit of time to learn

    but it is rather strait forward

    mmps is a good tool
    and easier to learn that "proj4" and "gdalwarp "
    --- 90 seconds to Midnight ---
    --------

    --- Penguin power!!! ---


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