About displaying terrain datasets in ArcGIS |
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Release 9.3
Last modified April 28, 2009 |
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Visualization of surface elevation data is very important. Being able to view data in 3D, color coded with elevation, sun shaded, blended with attribute data, and even draped with imagery, is becoming more customary. Three main regions exist for visualizing and working with elevation datasets: 2D map views, 3D scenes, and 3D globe views. ArcGIS provides applications that enable large elevation datasets to be stored and visualized using each distinct view. Rasters, TINs, and terrain datasets all provide a method to store and visualize terrain data in 3D.
Terrain datasets can be visualized as a 2D map in ArcMap and as a 3D globe in ArcGlobe through a terrain layer. This layer type is similar to TIN layers in some regards. It supports multiple renderers. You can view the triangles colored by elevation range, slope, aspect, and hillshade. You can also see the breaklines, triangle edges, and nodes of the triangulated surface. In terms of differences, terrains have the level of detail (LOD) capability that helps speed up the display, particularly at small scales, when a large volume of data is involved.
Rendering very large TINs is generally difficult, partially due to limitations of hardware such as video cards. Terrains are beneficial in that you render the areas that you need to visualize at an optimized resolution.
3D scenes can be generated using ArcScene. Natively, ArcScene does not directly support the terrain dataset. To generate resourceful surface models for a 3D scene, export the extents of the terrain dataset to a DTM raster surface.
The 3D globe surface in an ArcGlobe document can be derived from a terrain layer. The surface is rasterized on the fly to provide the information needed for the globe surface geometry. It may be more efficient to convert either a TIN or terrain layer to a raster DEM to avoid the ArcGlobe step of rasterization on the fly of triangulated data.
Terrain layer in ArcMap
Terrain layer in ArcGlobe
Terrain layer in ArcScene as a raster DEM
