VTP Software Tutorials
Tutorial 5: Placing Wind Turbines near a US City
tutorial was originally taught as a lab at the FOSS4G 2007 conference.
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:
- Raw data for this lab is in
- The very latest VTP applications. You should have the latest release
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
- 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
- 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
- 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
- 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
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
- Save the resulting layer as Data/RoadData/roanoke.rmf
- 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
- 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
- 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:
- Close Enviro.
- Surfing around, we find 1-meter CIR (Color Infrared) DOQQs at
but you don't need to download them, because:
- There are a few steps needed to use these images (beyond the scope of this
- 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
- 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
- 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.
- Make another structure layer. Add a few turbines to it, in different
- 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
13. Other cool things to try
- Use the distance tool to measure the distance from a turbine to the nearest
- 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.