{"id":103,"date":"2011-03-22T12:53:00","date_gmt":"2011-03-22T12:53:00","guid":{"rendered":"http:\/\/geoplanit.co.uk\/?p=103"},"modified":"2011-03-22T12:53:00","modified_gmt":"2011-03-22T12:53:00","slug":"digital-elevation-models-os-opendata-to-sketchup-a-workflow","status":"publish","type":"post","link":"https:\/\/www.geoplanit.co.uk\/?p=103","title":{"rendered":"Digital Elevation Models – OS OpenData to SketchUp : A workflow"},"content":{"rendered":"

Update: Geolocating the DEM in SketchUp has been solved see at bottom of page!<\/span><\/b>

<\/span><\/b>
So you have SketchUp and you\u2019ve heard wondrous things about the UK\u2019s Ordnance Survey OpenData<\/a>?!    In particular you hear there maybe some contour\/elevation models out there for free as well!   This quick workflow guide shows you how get that elevation model into SketchUp so you can plan horrible developments in undeserving places (I\u2019m a planner so I know…).<\/p>\n

Prerequisites:<\/span><\/b><\/p>\n

    \n
  1. Windows Vista (I\u2019m sure XP, Windows 7 etc.. all work as well)<\/li>\n
  2. SketchUp Pro (although you can import DEMs with the free version) http:\/\/sketchup.google.com\/intl\/en\/product\/whygopro.html<\/a><\/li>\n
  3. MicroDEM \u2013 follow the install guide to get yourself up and running http:\/\/www.usna.edu\/Users\/oceano\/pguth\/website\/microdem\/microdem.htm<\/a><\/li>\n
  4. OS OpenData, in particular the Land-Form Panorama dataset, select the download option enter your details (it only requires your email address) and then wait for  523MB zip file to download https:\/\/www.ordnancesurvey.co.uk\/opendatadownload\/products.html<\/a><\/li>\n
  5. Google Earth (to check your DEM is georeferenced properly)<\/li>\n
  6. You need a basic working knowledge of MS Windows, SketchUp and some file management skills. <\/li>\n<\/ol>\n
    Thanks to Chris Fullmer\u2019s website and his tutorial<\/a> <\/span><\/b><\/div>\n
    <\/div>\n

    Once downloaded you need to know what OS Grid square you want to import.   You can read the wiki article or I have used StreetMap <\/a>and once you\u2019ve searched for your location you can look just below the map and it says \u201cClick here to convert coordinates\u201d on this page LR seems to relate to the OS grid.
    http:\/\/en.wikipedia.org\/wiki\/Ordnance_Survey_National_Grid<\/a><\/p>\n

    <\/a>
    The Walkthrough<\/span><\/b><\/p>\n

    <\/div>\n

    Double click on the \u2018panorama_gb.zip\u2019 file and navigate to this directory \u2018\\DTM\\ASCII\\data\u2019.   Yes there are other types of data (contours as DXF and DEM as NTF) but this is what worked for me. <\/p>\n

    1 – Extract a tile from the directory name corresponding to your chosen OS tile.  In this case we\u2019re going to use Sedbergh, Cumbria tile which is under \u2018\\DYM\\ASCII\\data\\sd\\sd68.asc\u2019.  You can copy it to any directory but in this instance I tend to copy it to the \u2018mapdata\\DEMs\u2019 directory created by your installation of MicroDEM (you did install it right?)<\/p>\n

    2 – Load up MicroDEM and then click File –> Open DEM now navigate to the \u2018mapdata\\DEMs\u2019 directory and select the \u2018sd68.asc\u2019 file.<\/p>\n

    <\/a><\/div>\n

    3 – MicroDEM will ask you to pick its projection parameters as its OS OpenData my guess is that these settings are okay and then click \u2018Mercator\u2019 instead of \u2018OK\u2019 <\/p>\n

    <\/a><\/div>\n

    4 – The DEM should load up and look something like this :<\/p>\n\n\n\n\n
    <\/a><\/td>\n<\/tr>\n
    Nice Colours?<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    5 – If you want to get rid of the legend and scale bar and any grid that may appear right click on the image and select \u2018Legend\/marginalia\u2019.  Uncheck the boxes and click the \u2018Grid\u2019 button and select the option \u2018neither\u2019<\/p>\n

    <\/div>\n
    <\/a><\/div>\n
    <\/a><\/div>\n

    6 – Click \u2018OK(Close\u2019 and say \u2018yes to redraw… I often get errors and warnings at this point which I ignore….
    Now click on the menu heading file again and save this as a DEM and in particular a USGS ASCII one:<\/p>\n

    <\/a><\/div>\n

    7 – Once it is saved close MicroDEM and open up SketchUp…  I\u2019m assuming you will import into a fresh new SketchUp Model, so click on the File menu and select import.<\/p>\n

    <\/div>\n
    <\/a><\/div>\n

    8 – Choose the file type DEM (*.dem, *.ddf) and find that file you saved in MicroDEM, before you click open click on Options:<\/p>\n

    <\/a><\/div>\n

    9 – Here you can see I\u2019ve entered 20000 points to import the lower the number the less detail for this tile 20000 as suggested by Chris Fullmer\u2019s tutorial seems good<\/a>.  I suggest you experiment with this to get what you want though!  Also I\u2019ve check \u2018Generate gradient texture\u2019 this is entirely up to you, I suggest you first try with and then without.<\/p>\n

    The DEM should be imported and the axes, click the zoom extents button to check it\u2019s all there:<\/p>\n

    <\/a><\/div>\n
    <\/div>\n

    10 – Now to get rid of all those lines, double click the DEM (to edit component) and select all of the DEM (keyboard shortcut : \u2018ctrl-a\u2019).   Now right click the selected DEM and  click on \u2018Soften\/Smooth Edges\u2019:<\/p>\n

    <\/a><\/div>\n

    11 – As per Chris Fullmer\u2019s suggestion<\/a> slide to around 90 degrees and check both boxes (Smooth normals and Soften coplanar)<\/p>\n

    <\/a><\/div>\n

    12 – Et voila! You now have a terrain model for placing your models on! <\/p>\n\n\n\n\n
    <\/a><\/td>\n<\/tr>\n
    mmm smooth elevation model!<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    13 – One important thing to note this is not GeoReferenced.<\/b>  I haven\u2019t figured out why SketchUp doesn\u2019t load the DEM in the correct place.  If anyone has any suggestions please tell me (via Twitter <\/a>or otherwise<\/a>) and I\u2019ll add it to this tutorial.<\/p>\n

    Geo-Reference (or Geo-Locate) your DEM<\/span><\/b><\/p>\n

    14 – First you need to know where your DEM is in Latitude and Longitude you can do this by going to nearby.org Coordinate Convertor<\/a> and putting in your OS tile number (in this case SD68), I suggest you select output as Coordinate Conversion only:<\/p>\n

    <\/a><\/div>\n

    15 – You are now going to copy the Lat and Long coordinates into SketchUp so leave this webpage open and….<\/p>\n

    16 – In SketchUp click on the menu \u2018Window\u2019 then \u2018Model Info\u2019 and select \u2018Geo-Location\u2019<\/p>\n

    <\/a><\/div>\n

    17 – Give the Country name and location something meaningful…. and copy and paste your latitude and longitude\u2019s full number (and letter after) in the appropriate places.
    Now to test it press the Preview in Google Earth button:<\/p>\n

    <\/a><\/div>\n

    18 – If you\u2019re computer is up to it you should see the DEM appear in the correct location in Google Earth, it may take a while to load though so be patient!<\/p>\n\n\n\n\n
    <\/a><\/td>\n<\/tr>\n
    DEM Placed in GE<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    <\/p>\n

    <\/div>\n","protected":false},"excerpt":{"rendered":"

    Update: Geolocating the DEM in SketchUp has been solved see at bottom of page!So you have SketchUp and you\u2019ve heard wondrous things about the UK\u2019s Ordnance Survey OpenData?!    In particular you hear there maybe some contour\/elevation models out there for free as well!   This quick workflow guide shows you how get that elevation model […]<\/p>\n","protected":false},"author":161,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"tdm_status":"","tdm_grid_status":"","footnotes":""},"categories":[4,7,17,143,140,83,11,54,6,142,141,9],"tags":[],"class_list":["post-103","post","type-post","status-publish","format-standard","category-data","category-gis","category-maps","category-microdem","category-opendata","category-ordnance-survey","category-sketchup","category-tips","category-tools","category-tutorial","category-walkthrough","category-workflow"],"_links":{"self":[{"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=\/wp\/v2\/users\/161"}],"replies":[{"embeddable":true,"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=103"}],"version-history":[{"count":0,"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/103\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.geoplanit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}