Tarsier tutorial: Rendering symbols from rasters

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Outcomes

  • Render Fort Ord in a 3d realistic virtual reality
  • Use your land cover map to populate the visualization with trees and shrubs where appropriate, and at a density dictated by your % green cover map
FortOrd symbols.jpg

Prerequisites

Data

  • Fort Ord land cover map derived from Landsat (and associated land cover metadata) in tiff format.
  1. Exporting raster as tiff from ERDAS.
    1. Open ERDAS.
    2. Click the Importing button.
    3. The importing/exporting dialog should come up.
      1. Select the Exporting radio button.
      2. For Type select TIFF.
      3. For Media select File.
      4. Go to Input and browse to your NDVI raster.
      5. Go to Output and browse to your project folder. Give the output raster a meaningful name.
      6. Click OK
    4. Another window will come up.
      1. Uncheck the Create tile image option.
      2. For the Export Band Selection select "RGB"
      3. You might need to change the color channels
        1. Red should be 1.
        2. Green should be 2.
        3. Blue should be 3.
      4. Make sure the Create worldfile checkbox is enabled.
      5. Click OK.
  • Fort Ord % green cover derived from Landsat in tiff format.
  • Fort Ord true-color NAIP in tiff format.
  • DEM (download from USGS as a *.flt file - http://seamless.usgs.gov/index.php)
  1. Go to the left side of the USGS page and click on Seamless Viewer(under the "Tools to Access Data" section).
  2. Define download area
  3. Change to *.flt format
    1. Click on Modify Data request at the top of the download box
    2. Wait until the modify data request window loads
    3. Uncheck 1 arcsec and check 1/3 arcsec (for higer resolution DEM)
    4. Change dropdown from "ArcGrid" to "GridFloat"
    5. Save Changes at the bottom of the page
  • Tarsier needs to be loaded on your computer.
    • If you're using a computer where you have limited administrative privileges(i.e. lab computer).
      • Go to this this secure site and download zip file named "Fall 2010: Rendering symbols from raster tutorial files".
      • The folder contains all need it files and the Tarsier executable code.
    • If you're using a personal computer follow this instructions to install tarsier Download and install Tarsier.
      • Once Tarsier is installed download zip file that contains files need it for this tutorial this secure site.

Recomended Reading

Tarsier tutorial: Raster data

Tarsier tutorial: Raster resampler

Tarsier tutorial: Renderer

Tarsier tutorial: Simple fly-through

Introduction

In your remote sensing class you have developed and ground truthed a land cover map and an NDVI raster. You are now going to use that data in Tarsier.



Visualizing Fort Ord with the Renderer

  1. Open Tarsino by double clicking the Tarsino.exe file inside your Tarsier_Code folder.
  2. If no Tarsier modules(dlls) are loaded a message box will come up, follow the instructions to load modules.
  3. Load your DEM raster.
    1. File->Open.
    2. Navigate to the folder where you saved the raster from the USGS website. Select the .flt file and click open.
    3. This raster is in Latlon projection, we need to change it to UTM.
      1. Open the RasterResampler. File->New->Tools->Raster resampler.
      2. This form has 5 UseeControls like the generic one below:
        UseeControl.JPG
        UseeControls are one of the ways Tarsier loads and shares data, you can learn more about it here: Tarsier: UseeControl.
      3. Go to the Input Raster UseeControlDialog dropdown box and select your DEM raster.
      4. Now click on the 'Auto-create template for LL to UTM' button.
      5. Keep the RasterResampler window open and close your LatLon RasterView window.
      6. Go to the Output Raster UseeControlDialog and click the 'view' button. Your UTM DEM raster will come up.
      7. Save this raster.
        1. File->Save As
        2. Go to the second box and click the browse button. Browse to an appropriate folder and give the file a name (i.e. FortOrd_DEM_10m_UTM). Click the 'Save All' Button.
      8. Close both windows(RasterView and RasterResampler).
  4. Open the Renderer
    1. ->File ->New ->Data Views ->Render view ***Warning: If you didn't install Tarsier using the installer, you're going to get the message "default folder doesn't exist". Just press "Ok" When you see this message.***
  5. Make and view the Fort Ord terrain
    1. On the Raster tab (keyboard shortcut Ctrl+Shift+R) click the Make Terrain button.
    2. A UseeControlDialog dialog will come up. Click the open button and navigate to your Fort Ord DEM (UTM).
    3. After the raster is loaded click the OK button to start making the Terrain. When asked select the default name and folder for your Terrain files.
    4. Once the Terrain is created a message will come up asking if you want to load a color raster, click Yes.
    5. For the color raster we are going to use your true-color NAIP imagery (UTM). Click the open button and navigate to your Fort Ord NAIP imagery, click OK after the raster is loaded.
    6. A dialog box will come up asking if you want to set the Color Scheme to RGB, since our NAIP is true color click 'Yes'.
    7. Activate the Raster tab by clicking the check box at the upper left.
    8. If no other Terrains are loaded, Tarsino will automatically place you next to the Terrain you just created. Alternatively, you can go to the Cam 1 tab and click one of the camera icons on the left.
    9. You might notice some pink sections on your terrain. This means that there is no color data available for this section. If you want the make no data sections transparent uncheck the 'Draw nodata' checkbox in the Raster tab(upper right).
  6. Save the Renderview
    1. Make sure the Renderview window is selected. File->Save As
    2. Here you want to save the *.tre file which is the Top yellow box. Go to that box and click browse. Find an appropriate folder to save your file and give it a name. Click the Save All Checked button.

Now fly around your virtual reality. This is done by pressing the 'Ctrl+Shift+K' keys on your keyboard. You can then use the key controls to move your point of view.

Simplify the land cover map

Your land cover map has too many classes for our purposes. We will want to reclassify the map, distilling the classes down to just three: trees, shrubs, and other.

  1. Open your Fort Ord land cover map:
    1. ->File ->Open
    2. Navigate to your *.tif format land cover map and double click the file.
    3. Save file as *.tra, File->Save As.
      1. The Tarsier Save Dialog should come up. The top yellow box is the raster viewer file*.trv. The second box is your raster file*.tra. Go to the second box and click the browse button. Browse to an appropriate folder and give the file a name. Click the 'Save All' Button.
  2. Open the Raster Lookup tool:
    1. ->File ->New ->Tools ->Raster Lookup
  3. Load the land cover map into the Raster Lookup
    1. In the Raster Lookup view, use the drop down box next to Input Raster: to select your land cover map.
  4. Click the Find Values button
  5. This will display a table with a column, Input, for all the values from the input raster (your land cover map) and another column, Output, that will dictate the new values for the reclassified map. If the table does not display, then to the right of Lookup Table Data:, click the View button.
  6. Reclassify the map.
    1. Right now the "Output" column is filled with "-9999" which is the default null value. This will be the value of your "Other" class.
    2. For any input value that you think represent forest or trees, edit the corresponding output value by typing a "1" into the cell.
    3. For any input value that you think represent shrubs or chaparral, give the output value a "2".
    4. Save the Table Data
      1. File->Save As
      2. Go to the second box(should be red) and click the browse button. Browse to an appropriate folder and give the file a name. Click the 'Save All' Button.
  7. Go back to the Raster Lookup view and click the Execute button. This will create a new raster based on the table values.
  8. View and save your reclassified raster
    1. To the right of Output Raster 0: click the View button.
    2. Save the raster: With the Raster View window active, ->File ->Save As. . .
    3. Go to the second box (should be red) and click the browse button. Browse to an appropriate folder and give the file a name. Tarsino will recognise file names up to 255 characters (no spaces), so name your file something informative like "'Original file name'_ReclassifiedTo.Trees.Shrubs.Other.'yymmdd'.tra". Click the 'Save All' Button.
  9. You can now close the Original land cover map, the TableData, and the RasterLookup tool.

Creating Raster Symbol Scheme

The reclassified map has three classes, one of which is null (Other). You now need to let Tarsier know how you want the non-null classes to be visually represented in a render. One way to do this is to create a symbol scheme.

  1. Export your reclassified map to a Raster Symbol Scheme
    1. Make sure the raster view window is active, if not click on it.
    2. On the Main Menu ->Raster ->Export to RasterSymbolScheme (This should open a new view window).
  2. In the RasterSymbolScheme view you will see a list of all the non-null values from your reclassified raster. Click on unnamed 1 to edit its properties.
    1. Recall that the value "1" is to represent trees, so in the box next to Tag type Trees.
    2. Set the Density to 100.
    3. Set the Max Height to something reasonable for a Fort Ord tree, maybe 7 meters.
    4. Click Load Texture and navigate to your Oak.bmp
    5. Set the Transparent Color bar to the background color of the *.bmp file to make it transparent(pink indicates transparent).
  3. Similarly edit the properties for the shrub class (unnamed 2)
  4. Save your raster symbol scheme.

Visualizing the cover raster using the renderer

  1. Go back to the Renderview window
  2. Add in the land cover symbols
    1. On the Cvr tab, load the percent green cover raster (landcover.tra) into Cover (1k)
    2. On the Sym1 tab, load the reclassified land cover raster into the Symbol raster box
    3. Load the RasterSymbolScheme into the Raster Symbol Scheme box
    4. Change the symbol scheme from "Sphere" to "User Defined"
    5. Check the box to the left of Symbol raster
  3. Your trees and shrubs should show up on top of the Terrain.
  4. Go to the Sun tab and change the Elevation to 45 so you get more sunlight.
  5. Now get a screengrab by going to the Rec tab (Shorcut press 'R' Key) and click on the 'Grab Frame at 16 accum..' button.


Optional: Add Monterey bay raster and terrain

Who has taken this tutorial?

Please enter your user name at the bottom of this list, and the date:

  • Pam K-D

Links

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