GMS:Rasters

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Revision as of 14:27, 18 July 2012 by Unjedai (talk | contribs)
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DEMs (digital elevation models), and images that include elevation data such as a GeoTIFF, are referred to as "rasters". Using the third-party software Global Mapper, GMS supports a large number of DEM formats. DEMs are imported and displayed as images. Thus they are only displayed in plan view and are not true 3D surfaces like a TIN. The raster icon Raster.png is different from the image icon File:Image.png to indicate it includes elevation data. Rasters don't have to be DEMs. For example, the values at the pixels can represent concentrations, or flow rates ... or anything.

Importing DEMs

DEMs can be imported by simply opening the file(s) or dragging and dropping the file(s) into the GMS window.

Creating rasters

Rasters can be created from within GMS by interpolating from 2D scatter points. The interpolation options, the raster cell size, and the extents of the raster can all be specified in the Scatter -> Raster dialog.

Interpolating from rasters

Rasters can be interpolated to most other objects, including the z values of feature objects and to MODFLOW layers. The interpolation is done by finding the raster cells that the object's points are in and assigning the points the values from the raster cells.

Conversion from rasters

Rasters can be converted to a 2D grid or 2D scatter points.

Raster display options

The Rasters tab of the Display Options dialog is used to change the way rasters are displayed. The only options currently available are the shader which controls the color ramp, and whether to enable hill shading (shadows). These options are from Global Mapper.