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arma3:terrain:qgis-real-world-data-tutorial [2019-01-20 10:01]
snakeman fixed typos.
arma3:terrain:qgis-real-world-data-tutorial [2019-05-04 03:37]
snakeman
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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]]**
Line 36: Line 34:
 **For single tile export** **For single tile export**
  
-  * Load in just the '​.map'​ files generated ​in Terra Incognita into QGIS+  * Load in just the '​.map'​ files generated ​from Terra Incognita into QGIS
   * Merge rasters   * Merge rasters
   * Obtain extents from square feature   * Obtain extents from square feature
Line 43: Line 41:
 **For 4 tile export (large projects 40960 and above)** **For 4 tile export (large projects 40960 and above)**
  
-  * Load in just the '​.map'​ files generated ​in Terra Incognita into QGIS+  * Load in just the '​.map'​ files generated ​from Terra Incognita into QGIS
   * Merge Rasters   * Merge Rasters
   * Create grid -- 2 x 2 Feature   * Create grid -- 2 x 2 Feature
Line 54: Line 52:
  
 ===== 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**
Line 66: Line 66:
  
 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}}
Line 113: Line 113:
  
 {{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**
Line 143: Line 145:
  
 import os\\ import os\\
-os.system(r%%'''​%%gdalwarp ​**-t_srs EPSG:​32620** -wo SOURCE_EXTRA=1000 ​**-tr 5.0 5.0** -srcnodata "​-9999"​ -r cubic -of GTiff **-te 576787.687480 1841104.815839 597267.687480 1861584.815839 D:/​Arma/​Heightmaps/​Opentopo/​output_srtm.asc** **D:/​Arma/​QGIS/​Montserrat/​converted.tif**%%'''​%%)+os.system(r%%'''​%%gdalwarp -t_srs EPSG:**32620** -wo SOURCE_EXTRA=1000 -tr **5.0 5.0** -srcnodata "​-9999"​ -r cubic -ot Float32 ​-of GTiff -te **576787.687480 1841104.815839 597267.687480 1861584.815839 D:/​Arma/​Heightmaps/​Opentopo/​output_srtm.asc** **D:/​Arma/​QGIS/​Montserrat/​converted.tif**%%'''​%%)
  
 Some explanation of the key parameters: Some explanation of the key parameters:
Line 289: Line 291:
 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 and change the following:+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}}
  
-Before loading the asc file into Terrain Builder, delete the .prj file. Otherwise it will not import into TB.+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.
  
 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-09.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-09.png}}
Line 331: Line 336:
  
 {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-11.png}} {{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-11.png}}
 +
 +===== Preparing 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}}
 +
 +**Clip vector to square shape**
 +Top Menu - **Vector** > **Geoprocessing Tools** > **Clip**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-38.png}}
 +
 +Save features from clip to new shapefile -  selecting appropriate CRS, in this example **CRS UTM-20**\\
 +
 +Top Menu - **Layer** > **Save As**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-39.png}}
 +
 +**Set road shapefile to CRS - 31N**
 +
 +RMB on road shapefile > **Set CRS** > **Set Layer CRS**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-40.png}}
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-41.png}}
 +
 +**Set QGIS project CRS to UTM- 31N (bottom right corner):**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-42.png}}
 +
 +**Collect extents from your square shapefile:​**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-43.png}}
 +
 +Extent: (**576787.687480**,​ **1841104.815839**) - (597267.687480,​ 1861584.815839)
 +
 +The first two values will be used in the v.transform step below.
 +
 +
 +**v.transform on road shapefile using calculated extents from square shapefile**
 +
 +Your heightmap asc must adhere to Terrain Builders required values of **easting 200000** and **northing 0**
 +Your road shapefile also needs to line up to the same values - we will use **v.transform** to achieve this
 +
 +So taking the extent values we grabbed in previous step -\\
 +We will do the following calculations to bring these values to (**200000** and **0**):\\
 +**Easting: ​ 576787.687480 ​ - 376787.68748 = 200000**\\
 +**Northing: 1841104.815839 - 1841104.815839 = 0**\\
 +
 +**-376787.68748**\\
 +**-1841104.815839**
 +
 +
 +Having figured out the correct figures plug them into the **v.transform** process
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-44.png}}
 +
 +Drag and Drop into QGIS your heightmap asc - the one you are able to load into Terrain builder - already adjusted to (**200000**,​ **0**)
 +
 +Set CRS on above asc to **UTM - 31N**
 +
 +Right click on asc in **Layers** > **Zoom to Layer**
 +
 +In **Layers** panel drag the asc below your **transformed road shapefile** - so you can see the roads layered above the asc
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-45.png}}
 +
 +Your roads should now be perfectly aligned above your heightmap
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-46.png}}
 +
 +==== Setting ID and ORDER fields ====
 +
 +RMB on transformed shapefile layer > Toggle **Editing**
 +
 +RMB on transformed shapefile layer  > Open **Attribute Table**
 +
 +
 +Click **Delete field** - select all fields and press **OK**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-47.png}}
 +
 +New Field - Name '​**ID**'​ - length **0**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-48.png}}
 +
 +New Field - Name '​**ORDER**'​ - length 0
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-49.png}}
 +
 +Toggle - **Multi Edit mode**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-50.png}}
 +
 +ID - Enter **0** - click **Update All**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-51.png}}
 +
 +Select ORDER from drop down - Enter **1** - click **Update all**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-52.png}}
 +
 +Click - **Switch to table view**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-53.png}}
 +
 +Click **Save**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-54.png}}
 +
 +RMB on transformed road shapefile - **Toggle Editing** to save the changes
 +
 +
 +**Switching to Terrain Builder -**
 +
 +
 +**Load your road shapefile**
 +
 +Top menu - **File** > **Import** > **Shapes**
 +
 +Click **OK**
 +
 +{{https://​pmc.editing.wiki/​images/​Ross-QGIS-Tutorial-55.png}}
 +
 +Perfectly overlaid within **Terrain builder:**
 +
 +{{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:**
-  * Road shapefile creation 
   * 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.txt · Last modified: 2022-01-04 05:59 by snakeman