Howto:Create custom terrain: Difference between revisions

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# Click ''Map Search''.
# Click ''Map Search''.
# Click ETM+ (left column).
# Tick the ETM+ box (left column).
# Click on ''Update Map'' on the right bottom  of the map.
# Click on ''Update Map'' on the right bottom  of the map.
# Click on the ''Place''tab on the upper side of the map, in order to do a search by place, or you can do a search by latitude/longitude.
# Click on the ''Place'' tab on the upper side of the map, in order to do a search by place, or you can do a search by latitude/longitude.
# In the Place field, type ''Brest, France'' for instance.
# In the Place field, type ''Amsterdam, Netherlands'' for instance.
# Check that you have ''2 images in selection'' for example : this confirms that your selection is good. For Brest, there are two Landsat pictures to cover the area.
# Now click the button with the mouse and the small + sign. This will allow you to select image tiles. Select all images that cover your area of interest, in our example this is just one image.
# Click on ''Preview and download''. You will get the screen shown on the right. On the left you can check the picture you are going to download. The size of the pictures is also given.
# Click on ''Preview and download''. This bring you to a selection page were you can choose what image you want to download. It is likely that there are pictures available from different dates for your area. Picking the most recent one is best, for known reasons.  
# Click on ''Download'' to get a FTP access.
# Clicking the ID will not bring you directly to the download page, first you have to click the ''Download'' button.
# Only the files with a ''.tif.gz'' and ''.met'' extensions are of interest.
# Download the _nn80.tif.gz file (if this is not available, try an older image).
# Uncompress the ''.tif.gz'' files in the directory of your choice.
# Uncompress the ''.tif.gz'' files in the directory of your choice.


=== Working with QGIS ===
=== Working with QGIS ===
[[File:Capture-4.png|thumb|200px|QGIS with the TIFF image.]]
[[File:QGIS_texel_1.png|thumb|200px|QGIS with the TIFF image.]]
[[File:Capture-7.png|thumb|200px|Creating the class column.]]
[[File:QGIS_texel_2.png|thumb|200px|Creating the class column.]]
[[File:Capture-10.png|thumb|200px|Toggle editing]]
[[File:QGIS_texel_3.png|thumb|200px|Toggle editing.]]
[[File:Capture-12.png|thumb|200px|Tracing the island.]]
[[File:QGIS_texel_4.png|thumb|200px|Tracing the small island.]]
[[File:Capture-13.png|thumb|200px|The finished island polygon.]]
[[File:QGIS_texel_5.png|thumb|200px|The finished small island polygon.]]
[[File:Capture-15.png|thumb|200px]]
[[File:Capture-17.png|thumb|200px]]
Using a GIS software gives you the opportunity to realize a full range of interesting operations: modification of VMAP data, updates on the ground classification, etc...
Using a GIS software gives you the opportunity to realize a full range of interesting operations: modification of VMAP data, updates on the ground classification, etc...


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# Your vector layer should appear in the left-hand toolbar. You are ready to begin digitizing.
# Your vector layer should appear in the left-hand toolbar. You are ready to begin digitizing.
#Select the newly created layer in the layer list, toggle editing (<tt>Layer > Toggle Editing</tt>) and finally select Capture Polygon from the same menu/toolbar.
#Select the newly created layer in the layer list, toggle editing (<tt>Layer > Toggle Editing</tt>) and finally select Capture Polygon from the same menu/toolbar.
# With your mouse, left-click on a point at the southwestern edge of the island.
# With your mouse, left-click on a point at the southwestern edge of the small island.
# We now want to trace the outline of the island. Move your mouse to another point above the first point and click it again. Your mouse should show a red line. The points should not be redundant - for instance, as long as the line between two points is straight, there is no need for another point in between the two.
# We now want to trace the outline of the island. Move your mouse to another point below the first point and click it again. Your mouse should show a red line. The points should not be redundant - for instance, as long as the line between two points is straight, there is no need for another point in between the two.
# You will want to digitize features in a circular manner to avoid problems. You can always go back and add points later. With this in mind, move your mouse to a third point on the island. A small triangle should form, representing the polygon which would result if you decided you were done with the polygon.  
# You will want to digitize features in a circular manner to avoid problems. You can always go back and add points later. With this in mind, move your mouse to a third point on the island. A small triangle should form, representing the polygon which would result if you decided you were done with the polygon.  
# Continue outlining the island by clicking along its shoreline, initially moving to the right. When you are on your last point, instead of left-clicking, right-click. QGIS will finish the polygon.  
# Continue outlining the island by clicking along its shoreline. When you are on your last point, instead of left-clicking, right-click. QGIS will finish the polygon.  
# A dialog box will pop up, asking you to type in the value for 'class'. Since this is an island, covered with grass, type in ''GrassCover''. This step is important - it is how you know what each polygon should be mapped to in our finished scenery. A list of "allowed" materials (and thus classes) is available [http://wiki.osgeo.org/wiki/LandcoverDB_CS_Detail here].
# A dialog box will pop up, asking you to type in the value for 'class'. Since this is a shoal, existing of just sand, type in ''Sand''. This step is important - it is how you know what each polygon should be mapped to in our finished scenery. A list of "allowed" materials (and thus classes) is available [http://wiki.osgeo.org/wiki/LandcoverDB_CS_Detail here].


===Generating scenery===
===Generating scenery===

Revision as of 12:16, 15 November 2009

WIP.png Work in progress
This article or section will be worked on in the upcoming hours or days.
See history for the latest developments.

Look here an example of the achievable result.

Let's take a look at the Finistère in Brittany, Western France: if you click [1], you will quickly see and understand how the Finistère county is know of FlightGear. Some towns/city (red), a few forests (green), etc. Overall, it is not a very good resolution: a lot of angles, the detail level is not that good, some towns are missing. If you want a better definition on ground, there is some work to be done! The goal being to obtain something like this:

  1. Berlin
  2. Bodensee surroundings
  3. Oshkosh surroundings
  4. Carribs

You will immediately notice the improvement to the ground. When flying, the difference is huge. Moreover, this enables the autogeneration of cities, trees, farmland, and so on.

Downloading the Landsat pictures

Landsat Map Search
Preview and download Landsat image

Browse to the Earth Science Data Interface interface to grab your Landsat data.

  1. Click Map Search.
  2. Tick the ETM+ box (left column).
  3. Click on Update Map on the right bottom of the map.
  4. Click on the Place tab on the upper side of the map, in order to do a search by place, or you can do a search by latitude/longitude.
  5. In the Place field, type Amsterdam, Netherlands for instance.
  6. Now click the button with the mouse and the small + sign. This will allow you to select image tiles. Select all images that cover your area of interest, in our example this is just one image.
  7. Click on Preview and download. This bring you to a selection page were you can choose what image you want to download. It is likely that there are pictures available from different dates for your area. Picking the most recent one is best, for known reasons.
  8. Clicking the ID will not bring you directly to the download page, first you have to click the Download button.
  9. Download the _nn80.tif.gz file (if this is not available, try an older image).
  10. Uncompress the .tif.gz files in the directory of your choice.

Working with QGIS

QGIS with the TIFF image.
Creating the class column.
Toggle editing.
Tracing the small island.
The finished small island polygon.

Using a GIS software gives you the opportunity to realize a full range of interesting operations: modification of VMAP data, updates on the ground classification, etc...

  • If you run GNU/Linux, you can install QGIS with your usual package repositery manager; see here. The process is easy and not described here, but it is one the QGIS website.
  • If you are running Windows, download QGIS from here (Windows - Standalone).
  1. Launch QGIS.
  2. Click on Layer > Add a Raster layer.
  3. Modify the filter to search for *.tif files.
  4. Add the TIFF file you have just downloaded.
  5. Click on Layer > Add a new vector layer or on the corresponding icon. A dialog should pop up.
    • Make sure the file type is an ESRI Shapefile.
    • Make sure the vector type is set to polygon.
    • You need to create a data column for this layer. Create a column called 'class'. Make sure it is a string column. Add it to the attribute list by selecting the Add Values Manually button. The 'OK' button should now be available for you to select. Select 'OK'.
    • There should be a dialog box prompting you to save your vector layer. Save it in your scenery directory with your GeoTIFF. (This is not required but significantly helps organization.)
    • A projection box should pop up. Select 'WGS 1984'. After all, that is the globe model used in FlightGear.
  6. Your vector layer should appear in the left-hand toolbar. You are ready to begin digitizing.
  7. Select the newly created layer in the layer list, toggle editing (Layer > Toggle Editing) and finally select Capture Polygon from the same menu/toolbar.
  8. With your mouse, left-click on a point at the southwestern edge of the small island.
  9. We now want to trace the outline of the island. Move your mouse to another point below the first point and click it again. Your mouse should show a red line. The points should not be redundant - for instance, as long as the line between two points is straight, there is no need for another point in between the two.
  10. You will want to digitize features in a circular manner to avoid problems. You can always go back and add points later. With this in mind, move your mouse to a third point on the island. A small triangle should form, representing the polygon which would result if you decided you were done with the polygon.
  11. Continue outlining the island by clicking along its shoreline. When you are on your last point, instead of left-clicking, right-click. QGIS will finish the polygon.
  12. A dialog box will pop up, asking you to type in the value for 'class'. Since this is a shoal, existing of just sand, type in Sand. This step is important - it is how you know what each polygon should be mapped to in our finished scenery. A list of "allowed" materials (and thus classes) is available here.

Generating scenery

Please continue with TerraGear to generate the landclass into useable scenery.

External links

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