VTP Software Tutorials

Tutorial 5: Placing Wind Turbines near a US City

It will lead you step-by-step through the complete processing and visualization of a town.  Learn to take advantage of all the Federal, State and Local datasets, including the strengths and pitfalls of each USGS distribution format, in production of a complete 3D scene of a US city. The scenario will include placing and evaluating the landscape impact of constructing a wind turbine farm near a populated area.

Things you will need:

1. Raw data for this lab is in foss4g2007.zip (10 MB)
2. The very latest VTP applications.  You should have the latest release installed.

Target Area: Roanoke, Virginia

1. Set up your data path.

• Unless you already have a Data folder:
  • Create a folder called 'Data'.
  • Use Enviro terrain manager to add it to the data path.
• Use Enviro's terrain manager to create a new terrain file called Roanoke.xml
• Close Enviro.
• Copy some lab files into your Data folder:
  • roanoke_2048.jpg into Data/GeoSpecific
  • turbine2.osg into Data/BuildingModels
  • bus_routes* and schools* into Data/PointData

2. DEM

• Go to VTP USA page, look for Virginia.  Note that several sources for DEM exist.  Here are two that i already downloaded from the ATDI website, using the geo coords of the area (Geo: -79.9, 37.3; that's -79:55, 37:20).
• They are provided in your sample data.  Drag and drop them into VTBuilder:
  • 1694532_roanoke.dem.sdts.tar.gz
  • 1694525_daleville.dem.sdts.tar.gz
• Note they are 10m DEMs.
• We want an area just north of the city, and we want to match the 10m resolution of the data with the 1025*1025 LOD grid, so:
  •  Box: (589080.00, 4129450.00), (10240.00, 10240.00)
• Area Tool: Merge and Resample.  Output to Data/Elevation/roanoke_north.bt

3. Roads

• From browsing around, the Virginia State DOT provides the road network for the entire state.  But, that's rather large to work with.
• Instead, we could download the USGS DLG for transportation (in this case, it is found on the USGS site at http://edcftp.cr.usgs.gov/pub/data/DLG/LARGE_SCALE/R/roanoke_VA/transportation/)  But you don't need to download it.  It is already in your sample data for this lab.
• Drop 1205116.RD.sdts.tar.gz into VTBuilder.
• Use the road select tool (Roads: Select/Modify Roads) to select the roads we don't need, which are outside our area.  press Delete to delete them.
• Save the resulting layer as Data/RoadData/roanoke.rmf

4. Buildings

• Where do we get footprints?
• I found them on the Roanoke city GIS site (ftp://ftp.roanokegov.com/GIS/Shape_files/Buildings/)  This is a good example of a progressive local government which makes its data freely available, instead of expensive or difficult licensing.
• Drop the file buildings.shp into VTBuilder.  Observe that the projections are different.  Our current scene is using UTM, but the Roanoke City data is using State Plane coordinates.
• Press OK/Yes to allow VTBuilder to convert it for you.
• You should see the buildings for the whole city, most of which is south of the elevation grid.
• Select some features, then open the Attribute Table to see the columns.  Notice that height isn't a property, which is unfortunate (but common.)  Without height information, we can only import them all as the same height.
• Save the reprojected Raw layer to buildings_utm.shp, then delete the layer.
• Import buildings_utm.shp as a Structure layer.
  • Check the box for 'Only import features inside the Area Tool'.
  • Select roof type: Flat.
  • Press OK.
• Save the buildings to Data/BuildingData/roanoke.vtst

5. Terrain in 3D

• Launch Enviro.
• Set properties for the new terrain.
  • Name: "North of Roanoke, Virginia"
  • Grid filename: roanoke_north.bt
  • Triangle count: 40000
  • Texture: Derive from Elevation, 'default relative' color map.
  • Culture: Roads: roanoke.rmf
  • Culture: Structure Files: add roanoke.vtst
  • Navigation speed: 600 meters/frame
• Fly to the southern half of the terrain where the buildings are.
  • To find your way around, the Compass and Overview can be useful.
• Open the Location dialog, store a camera location, then save to Data/Locations/roanoke.loc

6. Time of day

• Open the Time dialog (menu Scene: Time, or the clock icon on the toolbar)
• Increase hour to advance time to a later time of day, see how the lighting changes on the buildings.
• Command Terrain: Reshade Terrain.  See how the lighting changes on the surface.
• Set time to 6:15 AM, and Reshade Terrain again.  Notice how the color of the sky changes and the sun casts a warm glow on the terrain:
• 

7. Imagery

• Close Enviro.
• Surfing around, we find 1-meter CIR (Color Infrared) DOQQs at http://geoserve.asp.radford.edu/doqq/R/roanoke_1_01.htm but you don't need to download them, because:
• There are a few steps needed to use these images (beyond the scope of this lab).
  • I used MrSID to convert the images to GeoTIFF, AlphaPixel CIR to make the colors more realistic, Global Mapper to reproject from NAD83 to NAD27, then VTBuilder to resample them into a single small 5m image.
• Launch Enviro.
• In the terrain parameters:
  • set Texture: Single Texture: roanoke_2048.jpg, and uncheck the 'Precompute Lighting' box
  • set Camera: Locations File: roanoke.loc, and Initial Camera Location
• Press "OK" twice, and the terrain view launches.  See how the aerial photo looks draped on the terrain

8. Building Editor

• Select a building, and try changing it's color, roof slope, height, door and windows.
• Use the Layer dialog to save your changes.

9. Wind Turbine

• In the Layers Dialog, create a new Structure layer, and make it active.
• Fly to the mountain in the south-east corner of the terrain.  A ridge-line is generally a good place to catch the wind:
• 
• Create Instances.  Instance from 3D Model File: Browse to turbine2.osg
• Click on the terrain to place instances.
• Practice moving the instances.  They can be rotated with Shift-drag, and deleted with right-click popup menu.
• In the Layers dialog, save the new layer as Data/BuildingData/turbines.vtst
• Jump back to your initial view.  See how the turbines look from a distance.  Turn them on and off with the Layers dialog.

10. Scenarios

• Make another structure layer.  Add a few turbines to it, in different places.
• View: Scenarios.  Define two scenarios, "Option 1" and "Option 2".  To each scenario, add the appropriate layers.
• Note that you can now switch back and forth between Scenarios by simply clicking them in the Scenarios dialog.

11. Manage your Content.

• Close Enviro.
• Launch the Content Manager.
• Open the file common_content.vtco
• Create a new Item, then add a Model to it.  Browse to Data/BuildingModels/turbine2.osg
• Give the item a name like "Wind Turbine" and a type "wind turbine":
• 
• Save content file to common_content.vtco
• The next time you launch Enviro, the wind turbine is already available in the Instance dialog, so you don't have to browse to the file.

12. Abstract Layers

• You can add abstract layers either in the Terrain Parameters Dialog (under 'Abstracts'), or at runtime with the Layer Dialog.
• Add an abstract layer, and select the bus_routes_utm.shp file.  Set its style:
  • Line Geometry: Enabled, Colour: Green, Height above ground: 15, Line width: 2, Tessellate
• Add an abstract layer, and select the schools_utm.shp file.  Set its style:
  • Text Labels: Enabled, Colour: Yellow, Text field: MAP_NAME, Height above ground: 30, Label size: 30
• In your 3D scene, you should see the bus routes and school labels, like this:
• 

13. Other cool things to try

• Use the distance tool to measure the distance from a turbine to the nearest house.
• A high-voltage transmission line corridor is clearly visible in the aerial photo.  Use Tools: Routes to create a power line along the corridor.
• Find an area that should have trees, which appears dark green in the aerial.  Use Tools: Plants, choose a tree species, and click to place them on the ground.
• Use Tools: Points to create some labeled placemarks on the terrain.