Home Forums Chat Forum Map contours into illustrator

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  • Map contours into illustrator
  • nickjb
    Free Member

    I’m making a map background and I’d like to use contours. The open cycle maps, which I believe come from nasa srtm data, look perfect. Is there anyway to get this in a usable vector format for illustrator? I’ve been plying around with Mapertive without much luck. I can export roads but not contours. The map section is in Ireland so can’t use OS Terrain 50 unfortunately. It is commercial so I can’t just go stealing something, but it is for a good cause so can’t pay licensing, just attribution. Any ideas?

    tillyfishes
    Free Member

    Are you looking for contours from a specific area or just anything that looks good?

    Don’t know anything about capturing them in vector format but i do have an application that can extract contours from certain types of maps to display them an export them as pdf.

    seosamh77
    Free Member

    kinda file is the source image? post an example?

    seosamh77
    Free Member

    Aye no joy, no contour data in those osm files by the looks of it, tried opening in QGIS, nothing happening there, think you’ll need to hunt for another source for the countour data, if it exists.

    nickjb
    Free Member

    Well the contour data must exist, mustn’t it. The link goes to a map showing contours. I believe it comes from nasa srtm data but I haven’t found a way I can use that data directly

    seosamh77
    Free Member

    Dunno tried that and opened in QGIS, download a the contour plug, but still saying no suitable data to creat contours.

    http://wiki.openstreetmap.org/wiki/Srtm2Osm

    ran that in command prompt (navigated to the exe folder)

    strm.exe -bounds3 “http://www.openstreetmap.org/#map=14/54.0225/-9.6562”

    so **** know, I’ve no idea, not that I should mind you, I know nothing about map data, nor QGIS! 😆

    Anyhow good luck, I’m out of ideas! (Main idea was to find something that would open in QGIS and export from there, but that’s flummoxed by the lack of contour data!)

    DavidB
    Free Member

    The workflow for this is possible but a bit involved:-

    1) download the DEM tile fro Ireland from http://dwtkns.com/srtm/ for the area you want
    2) make a contour shapefile with gdal_contour -a elevation -i 10 DEM.tif OUTPUT.shp
    3) Load the .shp file into QGIS and export as something Illustrator will read

    If it is a charitable cause and that lot stumps you then contact me via email and I’ll do it for you when I get a free moment (as long as I like the charity)

    EDIT: you can do whole thing in QGIS give me 10 minutes and I’ll post how

    OK download the Ireland DEM from the link I gave and unzip. Drag the file srtm_35_03.tif into QGIS

    From menus:-

    Raster then Extraction then Contour
    Select an Output file (anywhere you want)
    Change interval to whatever metres you want
    Click OK

    Contours appear after a while

    Select the contour layer
    Right click “Save As”
    Then use Print composer to export as SVG

    Final Edit: you will need more than one SRTM raster to cover all of Ireland. I have run out of time to tell you how to do this as must dash but it is Miscellaneous/Merge in QGIS.

    whitestone
    Free Member

    Does Illustrator have Bezier Curves? You could make your own if it does. Add in a bit of background shading and you’d be there.

    bigjim
    Full Member

    Creating contours from the DEM is a pain but as above is possible, though you tend to get weird artifacts, for example https://www.openstreetmap.org/export#map=17/54.03027/-9.68339&layers=C

    Have you looked at the actual cost of buying data? For a small area it might be very cheap. Be aware if you do use something derived from SRTM it isn’t going to be particularly accurate, it’s a bit of a generalised model of the world if you’re used to OS contours etc.

    bigjim
    Full Member

    First thing I’d do is get in touch, say what you’re doing, with your area extents, and see what they say https://www.osi.ie/products/professional-mapping/height-data/

    These guys are also excellent and I must have paid them many tens of thousands of pounds over the years, don’t think they cover ROI but it’s been a few years since I’ve asked the question http://www.emapsite.com/mapshop/default.aspx

    Also http://www.findmaps.co.uk/ https://www.landmark.co.uk/

    bigjim
    Full Member

    One last idea, do you really need line contours? Use the DEM and render in eg 10 metre classes with a nice colour gradient.

    leffeboy
    Full Member

    Qgis will do the contours but you need to spend a short time learning it. Try running through the tutorials a bit to find your way around and then Google for how to create them.

    ahsat
    Full Member

    If it’s commercial, you’d need to buy the data from OS (or supplier) or look at something like digimap. We use this for academic purposes. I pull the vectors into GIS file and then export into illustrator.

    Edit just realise you need Ireland 🙄 Equally must be able to purchase vector format from Irish mapping supplier.

    ahsat
    Full Member
    DavidB
    Free Member

    I completely disagree with SRTM not being accurate for a simple map which it seems the OP wants. SRTM contours match OS Terrain 50 pretty well. I know this because it is my job. My instructions above will get you contours in 10 minutes.

    bigjim
    Full Member

    It’s my job too and I would only ever use SRTM or OS terrain 50 for small scale eg overview maps where accuracy is not important, there is literally no budget, or where better data is not available eg Africa. OP did not specify it was a simple map so sensible to advise caution in case someone tries to use it for something it shouldn’t be used for. I’ve seen inaccurate elevation data cause serious problems before. If eg the OP is only looking at a very small area a few hundred m across and the data is the ~90m resolution srtm the contours are going to be… interesting. Also if the wgs84 data is not transformed correctly the contours could be >100m out of place against the other vector data providing further error.

    Ergo I would advise seeking the possibility of using existing contour data before ploughing into making ones own. OP may prefer to stump up £25 than spend time downloading, installing and fannying around with various things that might not be suitable anyway. If it’s for charity the data provider might surprise you in return for crediting the source.

    DavidB
    Free Member

    The open cycle maps, which I believe come from nasa srtm data, look perfect.

    Let’s leave it there

    joshvegas
    Free Member

    I have at my disposal Civil 3D

    And Infraworks 360.

    If you can send me files i’m fairly confident i can get what you want.

    Although i’m out of office for the next week so you may have a wait.

    When i say i have access… Its my job.

    Its also a 10minute job if you have the dem.

    None of this GIS fannying about.

    Infact if you even just sent the area you require i can probably do it for you without any files.

    bigjim
    Full Member

    None of this GIS fannying about.

    oh lord not cad 😆

    Let’s leave it there

    No I’d still advise OP spends a couple minutes on the blower first after the good stuff before attempting DIY, unless he’s keen to learn qgis and has the time to. Even then after that I’d still consider just rendering the dem in 10m classes rather than creating polylines, takes a few seconds and should look pretty sweet for a background map.

    Tempted to try it myself to learn qgis so I can divorce from esri

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