6,566
edits
Howto:Create custom terrain: Difference between revisions
Jump to navigation
Jump to search
m
Switch to the {{forum link}} template for all forum links.
(Update to QGis 1.7.0, correct CRS settings, no conversion needed (!)) |
m (Switch to the {{forum link}} template for all forum links.) |
||
| (8 intermediate revisions by 6 users not shown) | |||
| Line 1: | Line 1: | ||
Custom terrain in FlightGear is currently generated through processing shapefiles with [[TerraGear]]. In order to add custom scenery to FlightGear, you must create a custom shapefile. | '''Custom terrain''' in [[FlightGear]] is currently generated through processing shapefiles with [[TerraGear]]. In order to add custom scenery to FlightGear, you must create a custom shapefile. | ||
A | A shapefile is a proprietary spatial information format. You can edit them with almost every GIS package. QGIS is quite a good package for this type of project. | ||
Your goal for editing area data is to create a shapefile of a seamless layer of polygons which correspond to some type of land cover. This data is then fed into the mapserver and, possibly, TerraGear to create new scenery. | Your goal for editing area data is to create a shapefile of a seamless layer of polygons which correspond to some type of land cover. This data is then fed into [http://mapserver.flightgear.org the mapserver] and, possibly, TerraGear to create new scenery. | ||
=== Evaluating the current data === | === Evaluating the current data === | ||
Before you begin, please make sure the area you want to improve doesn't already have good coverage. Just because it looks bad in FlightGear does not mean the area has not been improved. For this, you will need to check the Flightgear Mapserver, at [http://mapserver.flightgear.org/ mapserver.flightgear.org]. | Before you begin, please make sure the area you want to improve doesn't already have good coverage. Just because it looks bad in FlightGear does not mean the area has not been improved. For this, you will need to check the Flightgear Mapserver, at [http://mapserver.flightgear.org/ mapserver.flightgear.org]. | ||
Let's take a look at the Finistère in Brittany, Western France: if you click [http://mapserver.flightgear.org/map/?lon=-4.41840585539649&lat=48.4484146908477&zoom=11&layers=0B000000FTTFFFFFTFT here], you will quickly see and understand how the Finistère county | Let's take a look at the Finistère in Brittany, Western France: if you click [http://mapserver.flightgear.org/map/?lon=-4.41840585539649&lat=48.4484146908477&zoom=11&layers=0B000000FTTFFFFFTFT here], you will quickly see and understand how FlightGear interprets the data pertaining to Finistère county. Some towns/cities (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: | ||
# [http://mapserver.flightgear.org/map/?lon=13.40385&lat=52.50199&zoom=11&layers= | # [http://mapserver.flightgear.org/map/?lon=13.40385&lat=52.50199&zoom=11&layers=B0000000TFFFTFFFTFFFFFFF Berlin] | ||
# [http://mapserver.flightgear.org/map/?lon=9.40368&lat=47.63699&zoom=11&layers= | # [http://mapserver.flightgear.org/map/?lon=9.40368&lat=47.63699&zoom=11&layers=B0000000TFFFTFFFTFFFFFFF Bodensee surroundings] | ||
# [http://mapserver.flightgear.org/map/?lon=-88.55704&lat=43.98436&zoom=11&layers= | # [http://mapserver.flightgear.org/map/?lon=-88.55704&lat=43.98436&zoom=11&layers=B0000000TFFFTFFFTFFFFFFF Oshkosh surroundings] | ||
# [http://mapserver.flightgear.org/map/?lon=-62.87648&lat=17.69865&zoom=10&layers= | # [http://mapserver.flightgear.org/map/?lon=-62.87648&lat=17.69865&zoom=10&layers=B0000000TFFFTFFFTFFFFFFF Carribean Islands] | ||
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. | 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. | ||
| Line 20: | Line 20: | ||
[[File:C31e36f2a2cbb278a1603dfe2ba91193.media.395x288.png|thumb|200px|Landsat Map Search]] | [[File:C31e36f2a2cbb278a1603dfe2ba91193.media.395x288.png|thumb|200px|Landsat Map Search]] | ||
[[File:1c9334d970963364b5ce1bc3a166a4fa.media.426x192.png|thumb|200px|Preview and download Landsat image]] | [[File:1c9334d970963364b5ce1bc3a166a4fa.media.426x192.png|thumb|200px|Preview and download Landsat image]] | ||
Browse to [http://glcfapp. | Browse to [http://glcfapp.glcf.umd.edu:8080/esdi/index.jsp the Earth Science Data Interface interface] to grab your [http://en.wikipedia.org/wiki/Landsat Landsat] data. | ||
# Click ''Map Search''. | # Click ''Map Search''. | ||
| Line 48: | Line 48: | ||
# Modify the filter to search for *.tif files. | # Modify the filter to search for *.tif files. | ||
# Add the TIFF file you have just downloaded. | # Add the TIFF file you have just downloaded. | ||
# Rightclick on the image in the layer sidebar and choose <tt>Set layer CRS</tt>, to select a projection model. This depends on the location of the area you're about to create. Look up your project's UTM coordinate through [http://upload.wikimedia.org/wikipedia/commons/e/ed/Utm-zones.jpg this image]. For Texel this is 31U, north of the equator, so we choose <tt>Projected Coordinate Systems > Universal Transverse Mercator (UTM) > WSG84 / UTM zone 31N</tt>. Always select 'WGS84', as that is the globe model used in FlightGear. | # Rightclick on the image in the layer sidebar and choose <tt>Set layer CRS</tt>, to select a projection model. This depends on the location of the area you're about to create. Look up your project's UTM coordinate through [http://upload.wikimedia.org/wikipedia/commons/e/ed/Utm-zones.jpg this image]. For Texel this is 31U, north of the equator, so we choose <tt>Projected Coordinate Systems > Universal Transverse Mercator (UTM) > WSG84 / UTM zone 31N</tt>. Locations south of the equator may need to use the 'N' zones as well. For example, the correct projection for Perth, Australia is <tt>Projected Coordinate Systems > Universal Transverse Mercator (UTM) > WSG84 / UTM zone 50N</tt>. Always select 'WGS84', as that is the globe model used in FlightGear. | ||
# Click on <tt>Layer > New > New Shapefile Layer</tt> or on the corresponding icon. A dialog should pop up. | # Click on <tt>Layer > New > New Shapefile Layer</tt> or on the corresponding icon. A dialog should pop up. | ||
## Make sure the vector type is set to polygon. | ## Make sure the vector type is set to polygon. | ||
| Line 65: | Line 65: | ||
Continue with tracing all shapes on the island: towns, industrial areas, grass, farmland etc. | Continue with tracing all shapes on the island: towns, industrial areas, grass, farmland etc. | ||
# Open <tt>Settings > | ===Snapping=== | ||
# Click the tickbox(es) in front of your layer(s) and set Tolerance to 20 (map units). A smaller tolerance will make it easier to work with very small and detailed layers. | It is very important to enable "snapping" now. | ||
Snapping means each polygon will fit together nicely, like a jigsaw puzzle. If snapping is not enabled, the polygons will not form a continuous layer, which has a number of different problems. | |||
We don't want small holes in our scenery, nor do we want overlapping polygons. Snapping adjusts each point as you go by - you will miss occasionally and have to correct it - so you don't have to worry about lining the polygons up precisely. | |||
# Open <tt>Settings > Snapping Options</tt>. | |||
# Click the tickbox(es) in front of your layer(s) and set Tolerance to 20 (map units). A smaller tolerance will make it easier to work with very small and detailed layers, while a bigger value makes it easier to snap when zoomed out. | |||
# Click OK to save the snapping options. | # Click OK to save the snapping options. | ||
==== Distinguishing Land Class Types from LANDSAT data ==== | ==== Distinguishing Land Class Types from LANDSAT data ==== | ||
You may Google Maps or Yahoo Maps running alongside your program to see what is what on the black/white image, but most areas are recognizable without use of the software. If you need help determining what part of the black-and-white image, please currently refer to the [http://stattosoftware.com/flightgear/tutorial/index.html#distinguishing original Stattosoftware Scenery Tutorial]. Instead of determining in a single band image you can also combine different ETM+ bands in a RGB file. Some information about different band combinations can be found here [http://web.pdx.edu/~emch/ip1/bandcombinations.html]. | You may Google Maps or Yahoo Maps running alongside your program to see what is what on the black/white image, but most areas are recognizable without use of the software. If you need help determining what part of the black-and-white image, please currently refer to the [http://stattosoftware.com/flightgear/tutorial/index.html#distinguishing original Stattosoftware Scenery Tutorial]. Instead of determining in a single band image you can also combine different ETM+ bands in a RGB file. Some information about different band combinations can be found here [http://web.pdx.edu/~emch/ip1/bandcombinations.html]. | ||
| Line 77: | Line 83: | ||
In order to turn the landclass into scenery we have to split it into seperate shapefiles for each landclass. | In order to turn the landclass into scenery we have to split it into seperate shapefiles for each landclass. | ||
# Open the Attribute table (<tt>Layer > Open Attribute | # Open the Attribute table (<tt>Layer > Open Attribute Table</tt>). | ||
# Type "Sand" (or another class) into the search box and press the Search button. This will select all polygons that have the Sand class assigned. | # Type "Sand" (or another class) into the search box and press the Search button. This will select all polygons that have the Sand class assigned. | ||
# Go to <tt>Layer > Save Selection as | # Go to <tt>Layer > Save Selection as vector file</tt> and save the sand shapefile somewhere on your computer. | ||
# Do the same for all other classes. | # Do the same for all other classes. | ||
# To make the difference between land and sea (landmass) we save the entiry shapefile (<tt>Layer > Save as | # To make the difference between land and sea (landmass) we save the entiry shapefile (<tt>Layer > Save as...</tt>, ESRI Shapefile). | ||
If you want to see these shapefiles integrated into the Custom Scenery database you can contact papillon81 and statto (through IRC or Forum). Please be remembered that your data has to be derived from freely available (public domain) sources. Other material can not be integrated due to legal issues. | If you want to see these shapefiles integrated into the Custom Scenery database you can contact papillon81 and statto (through IRC or Forum). Please be remembered that your data has to be derived from freely available (public domain) sources. Other material can not be integrated due to legal issues. | ||
| Line 89: | Line 95: | ||
== External links == | == External links == | ||
{{forum|5|scenery enhancement}} | |||
* [http://www.custom-scenery.org Terragear-cs website] | * [http://www.custom-scenery.org Terragear-cs website] | ||
* [http://wiki.qgis.org QGIS Wiki] | * [http://wiki.qgis.org QGIS Wiki] | ||
* [http://wiki.osgeo.org/wiki/LandcoverDB_CS_Detail OSGEO Wiki] | * [http://wiki.osgeo.org/wiki/LandcoverDB_CS_Detail OSGEO Wiki] | ||
* {{forum link|t=5566|text=Editing shapefiles for inclussion in official scenery}} (forum topic) | |||
=== Resources === | === Resources === | ||
* [http://stattosoftware.com/flightgear/tutorial/index.html Tutorial by John Holden] | * [http://stattosoftware.com/flightgear/tutorial/index.html Tutorial by John Holden] | ||
[[Category:Howto | [[Category:Howto]] | ||
[[Category:Scenery enhancement | [[Category:Scenery enhancement]] | ||
[[fr:Howto: Utiliser QGIS et images satellites]] | |||