EN/CityGML-Tutorial/chapter-2:-Building/LOD1.md

@@ -137,6 +137,8 @@ In this example, a shapefile of building footprints having height value as attri
 
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+>If your shapefiles are in WGS 84 (EPSG:4326) then first reproject it to a projected coordinate system (PCS) that is relevant to your location using FME transformer Reprojector. If the shapefiles are not reprojected to a PCS, solids having wrong orientation will be generated.
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 First, the FME Workbench is started with an empty workspace. The building footprints are read using a reader (Readers -> Add Reader). The 3D building geometry is now derived with the help of so-called transformers. A transformer is always a block into which input data goes, which is processed and forwarded to other blocks via output data port. Blocks linked in this way form a workbench. In the so-called Transformer Gallery, you will find all the transformers that are available in FME. About the notation: names of transformers are written in bold , parameters and connections in italic.
 
 The building footprint shapefile can be extruded into a 3D geometry with the transformer **Extruder**. To do this, the reader output is connected to the input of the **extruder** . Now the **extruder** has to be told at which height the footprints should be extruded. To do this, the attribute HEIGHT is set as the value for the parameter *Distance* in the properties dialog of the **extruder** . In order to view the generated data, a so-called **inspector** (right mouse button) can be inserted into the process, which is connected to the *Extruded* output port of the **extruder** .