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arma3:terrain:qgis-real-world-data-tutorial [2019-02-11 02:57]
snakeman added new update from ross.
arma3:terrain:qgis-real-world-data-tutorial [2019-03-31 23:28] (current)
snakeman added new update from ross.
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 The goal was to achieve an export satellite image and heightmap with the same or better quality than would be possible with Global Mapper. The goal was to achieve an export satellite image and heightmap with the same or better quality than would be possible with Global Mapper.
  
-The is my second revision of this process as recently discovered that due to an update to GDAL (**2.4.0**) one of the key steps in the original tutorial using '​**Clip Raster by Mask Layer**'​ no longer works perfectly!+I've used GDAL command lines where possible, which simplifies ​the process a little, and reduced additional processing on the data.
  
-So I reworked the process by getting a bit more under the hood, and using GDAL command line where possible, this also simplifies the process a little and reduced even further processing on the data. +The following software ​versions were used for this tutorial:
- +
-This tutorial used the following software:+
  
 **[[https://​qgis.org/​en/​site/​forusers/​download.html|QGIS v3.4.3]]** **[[https://​qgis.org/​en/​site/​forusers/​download.html|QGIS v3.4.3]]**
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 ===== Heightmap: ===== ===== Heightmap: =====
 +
 +This tutorial covers single raster heightmap as per the kind you will find on opentopo [[http://​opentopo.sdsc.edu/​raster?​opentopoID=OTSRTM.082015.4326.1|here]],​ I will detail steps for heightmaps spread across muliptle rasters in another update. as they will require additional steps likely including Merge / Build Virtual Raster commands. This section does not cover any re scaling of heightmap, which I would recommend against anyway. Remember [[https://​pmc.editing.wiki/​doku.php?​id=arma:​terrain:​grid_cell_size|Grid size x Cell size]] should = the same size (meters) as your source heightmap selection.
  
 **Drag and drop your heightmap '​.asc'​ into QGIS** **Drag and drop your heightmap '​.asc'​ into QGIS**
  
-This tutorial covers single raster heightmap as per the kind you will find on opentopo [[http://opentopo.sdsc.edu/​raster?​opentopoID=OTSRTM.082015.4326.1|here]],​ I will detail steps for heightmaps spread across muliptle rasters ​in another update. as they will require additional steps likely including Merge / Build Virtual Raster commands.+If you do use opentopo ​for source of Heightmap, make sure extract both the **.asc** and **.prj** files before proceeding with belowThey should both be in the zip file from opentopo.
  
 **Set QGIS to appropriate CRS for location of your HM** **Set QGIS to appropriate CRS for location of your HM**
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 Select the CRS to match your real world data, in this example its ‘**WGS 84 UTM zone 20N**’ because the terrain is from the Montserrat in the Caribbean. See also [[https://​pmc.editing.wiki/​doku.php?​id=arma3:​terrain:​utm-projection|UTM projection]].\\ Select the CRS to match your real world data, in this example its ‘**WGS 84 UTM zone 20N**’ because the terrain is from the Montserrat in the Caribbean. See also [[https://​pmc.editing.wiki/​doku.php?​id=arma3:​terrain:​utm-projection|UTM projection]].\\
-This will ensure your QGIS project space works appropriately with any other data you want to add - eg road shapefiles etc. Terrain Builder will only use UTM 31N but we'll get to that later.+This will ensure your QGIS project space works appropriately with any other data you want to add - eg road shapefiles etc. Terrain Builder will only use **UTM 31N** but we'll get to that later.
  
 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-13b.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-13b.png}}
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 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-21.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-21.png}}
 +
 +Save the above edits to the shapefile by clicking on the layer & selecting ‘**Toggle Editing**’
  
 **Obtain extents from square feature** **Obtain extents from square feature**
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 And list them out for safe keeping - And list them out for safe keeping -
  
-TL -  Extent: (576787.687480,​ 1851344.815839) - (587027.687480,​ 1861584.815839)\\ +**TL -  Extent**: (576787.687480,​ 1851344.815839) - (587027.687480,​ 1861584.815839)\\ 
-TR -  Extent: (587027.687480,​ 1851344.815839) - (597267.687480,​ 1861584.815839)\\ +**TR -  Extent**: (587027.687480,​ 1851344.815839) - (597267.687480,​ 1861584.815839)\\ 
-BL -  Extent: (576787.687480,​ 1841104.815839) - (587027.687480,​ 1851344.815839)\\ +**BL -  Extent**: (576787.687480,​ 1841104.815839) - (587027.687480,​ 1851344.815839)\\ 
-BR - Extent: (587027.687480,​ 1841104.815839) - (597267.687480,​ 1851344.815839)\\+**BR - Extent**: (587027.687480,​ 1841104.815839) - (597267.687480,​ 1851344.815839)\\
  
 **Run GDAL command for each quarter to set cell size and CRS and clip to shapefile square extents** **Run GDAL command for each quarter to set cell size and CRS and clip to shapefile square extents**
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 ===== Loading your assets into Terrain Builder ===== ===== Loading your assets into Terrain Builder =====
  
 +I would recommend saving copies of any files to be used in **Terrain Builder** into a separate terrain project folder. This will prevent your source project files being adversely affected, and potentially no longer working within **QGIS** - particularly relevant to those changes mentioned below.
  
 **Heightmap (.asc) edits** **Heightmap (.asc) edits**
  
-Open your **asc** in notepad and change the following to ensure it loads in Terrain builder:+Open your **asc** in notepad and change the following to ensure it loads in **Terrain builder**:
  
 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-14.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-14.png}}
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 Save to a new asc, whilst maintaining the original for use in your QGIS project space Save to a new asc, whilst maintaining the original for use in your QGIS project space
  
-Before loading the asc file into Terrain Builder, delete the .prj file. Otherwise it will not import into TB.+Before loading the asc file into **Terrain Builder**, delete the .prj file. Otherwise it will not import into TB.
  
 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-09.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-09.png}}
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 ===== Preparing Road Shapefile ===== ===== Preparing Road Shapefile =====
  
-**Load ​in road shapefile**+**Load ​into QGIS (drag and drop) road shapefile** 
 + 
 +In this example I got a good dataset from - [[https://​data.humdata.org/​|https://​data.humdata.org/​]]
  
 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-37.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-37.png}}
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 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-38.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-38.png}}
  
-Save features from clip to new shapefile -  selecting ​correct ​**CRS UTM-20**\\+Save features from clip to new shapefile -  selecting ​appropriate CRS, in this example ​**CRS UTM-20**\\
  
 Top Menu - **Layer** > **Save As** Top Menu - **Layer** > **Save As**
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 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-56.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-56.png}}
  
 +===== 3D Preview using Qgis2threejs =====
 +
 +If you want to see an instant 3d preview of your terrain within QGIS you can with the amazing plugin **Qgis2threejs**
 +
 +First install it:
 +
 +Top menu > **Plugins** > **Manage and Install Plugins**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-57.png}}
 +
 +RMB on the Merged layer and select **Zoom to Layer**
 +
 +Then select both the **Merged** raster, and the original source heightmap - deselect all other layers
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-58.png}}
 +
 +Start the Qgis2threejs plugin - Top Menu > **Web** > **Qgis2threejs** > **Qgis2threejs Exporter**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-59.png}}
 +
 +Select source heightmap and nothing else
 +
 +RMB on heightmap > **Properties**
 +
 +Set the **Resampling** level to **6**
 +
 +Set **Resolution** to **400%**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-60.png}}
 +
 +Enjoy browsing around your terrain in 3D:
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-61.png}}
 +
 +You can also export your terrain to a browser interface if you want - **File** > **Export to web**
  
 **Coming Soon:** **Coming Soon:**
   * Assisted image classification - for creation of mask   * Assisted image classification - for creation of mask
-  * 3d preview using Qgis2threejs 
arma3/terrain/qgis-real-world-data-tutorial.1549853858.txt.gz · Last modified: 2019-02-11 02:57 by snakeman