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A 3-D View of the world. Why 3 D?. It is difficult to interpret a landscape from 2-dimensional maps. A 3D view of the landscapes provides easy identification of changes in terrain throughout Exaggeration of surface elevation Lightening Draping images. Software.
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Why 3 D? • It is difficult to interpret a landscape from 2-dimensional maps. • A 3D view of the landscapes provides easy identification of changes in terrain throughout • Exaggeration of surface elevation • Lightening • Draping images
Software • Commercial software such as ArcView and ArcMap are provided within a package that allows a 3D view of the terrain. • Other software are downloadable for free from internet, but they have limits in their applications.
Where can we find 3dMapper? • Step 1: go to http://solim.geography.wisc.edu/mapper/index.htm • Step 2: go to ftp://solim.geography.wisc.edu/OUT/jburt/3dMapper • Step 3: save all the files under an appropriate folder (name it 3dMapper)
Resolution Floating allows to zoom in and out quickly Floating
Resolution Filtering Filtering is the process which transforms the landscape so that the edges are either smoother (low pass filter) or sharper (high pass filter) For changing the filter: -click on option -activate “filter local view” The default filter is a low pass filter
Importing files from other software • The free version of 3dMapper is not able to import files from other software, such as ArcView and ArcMap • Thus, lets have a look at what we can do directly using ArcMap and ArcView!
ARCMAP/ArcScene • Open ArcScene • Add the following files: • DEM • Roads • Aerial Photograph
Create the 3D effect • Right click on the DEM layer • Go to Layer Properties/ Base Heights • Change the default to “Obtain heights for layer from surface” • Choose the DEM • Assign a value of 5 to the Z Unit Conversion • Repeat for all layers
3D Analyst • As in ArcMap, ArcScene provides 3D Analyst. • 3D Analyst allows to compute: slope, aspect, contour lines, hillshade • It provides filters for modifying the resolution • All types of GIS layers generated throughout ArcMap can be open in ArcScene
ArcView • Open ArcView • Add the DEM • Go to View/ 3D Scene • Choose “Themes”
Exaggerating the elevation • Go to Theme/ 3D Properties • Change the default to “Surface” and select the DEM • Change the Z-Factor to 5
Surfaceanalysis • Go to Surface/ Create Contours
Adjust the Z-value for the contours • Go to Theme/ 3D Properties
Draping Aerial Pictures • Go to File/Extension under the main Viewer • Turn on MrSID Image Support
Draping Aerial Pictures • Add the aerial photographs to the 3d Scene Viewer • Adjust the Z-value