Description
The Terrain object is used to model terrain features in FreeFlyer. Terrain can be considered when computing the height of a location on the Earth and when computing line-of-sight visibility between two objects, whether they are orbiting in space, or stationary or moving objects on the ground. See the Terrain Modeling Guide for more information.
Inheritance Hierarchy: ObjectàTerrain
Available In Editions:
Mission
Timing Precision Mode
This page describes functionality in millisecond timing precision mode.
Name
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Description
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DeclaredName
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The name of the object as declared.
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Filenames
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The filenames for each of the terrain data files that have been added to this object. Files can be added using the Terrain.AddFiles() or Terrain.AddFilesInDirectory() methods. FreeFlyer will search for the required matching FreeFlyer Terrain Index File in the same directory as the raw terrain data file, but with the FreeFlyer Terrain Index File extension (.ffidx).
Note: If any of the indices for the Terrain Filenames cannot be found, FreeFlyer will report an error saying that the Terrain object configuration is invalid because one or more index files couldn't be found.
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HeightQueryCacheSize
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Maximum number of records that will be saved in a cache for terrain height queries. The size of a record is a function of the loaded terrain file sizes. For a typical terrain file containing 3601x3601 pixels, a record contains a 16x16 region of pixels.
Attempting to change this value after the cache is already in use will result in an error.
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MeshCacheSize
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Maximum number of records that will be saved in a cache for evaluating line of sight visibility with occulting terrain. The size of a record is a function of the resolution of the FreeFlyer Terrain Index File. For example, when using an index resolution of 8, a record contains a 256x256 region of pixels.
Attempting to change this value after the cache is already in use will result in an error.
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Name
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The name displayed for this object in output windows such as views, plots, and reports.
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ObjectId
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The unique identifier for the object.
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ObjectType
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The type of the object.
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Name
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Description
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AddFiles
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Add terrain files to the Terrainobject. Terrain raster files need to be pre-processed with the FreeFlyer Terrain Index Generator before they can be used in FreeFlyer.
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AddFilesInDirectory
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Add all the files with the specified file extension in the specified directory to the Terrain object. Terrain raster files need to be pre-processed with the FreeFlyer Terrain Index Generator before they can be used in FreeFlyer.
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ClearSavedStates
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Clears previous saved states for this object.
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ContainsLocation
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Returns true if the provided latitude and longitude are contained in any of the terrain data files with this dataset.
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GetFromFile
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Load the object state from the specified FreeFlyer object file.
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GetFromString
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Load the object state from the specified string.
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GetHeight
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Returns the terrain height with respect to the Earth ellipsoid at the specified latitude and longitude. The Earth uses the WGS84 ellipsoid by default. This method will raise an error if the provided latitude and longitude are outside the bounds of any available terrain data. The Terrain.ContainsLocation() method can be used to check whether a location is within the bounds of any of the available terrain data.
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PutToFile
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Convert the object state to FreeFlyer object xml and write to a file.
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PutToString
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Convert the object state to FreeFlyer object xml and return as a string.
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ReferenceEquals
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Returns 1 if the argument refers to the calling object and 0 otherwise.
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RemoveAllFiles
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Remove all terrain data files from the Terrain object.
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Restore
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Restore an object's state from a previously saved state.
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Save
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Save the object's state so that it can be restored later.
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