Tarsier tutorial: Renderer

From CCoWS Wiki
Revision as of 09:43, 24 November 2010 by Pamk (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

What is the 'Renderer'?

Strictly speaking, a renderer is any process that produces a visual representation of some data. So a RasterView is a renderer. However, the Renderer in Tarsier conventionally refers to the main 3D renderer that is used to produce most 3D visualizations.

The Renderer draws 3D scenes described by a wide range of data, including multiple rasters, vectors, sites, etc.

Pre-requisites for this tutorial?

Using the Renderer to view some raster data and nothing else

  1. Open Tarsier
  2. Open a new Renderer
    1. Select File --> New --> Data Views --> Render View (if its not on the list, you need to load a DLL)
  3. Load some RasterData into the Renderer. The raster would normally represent elevations, as in topography or bathymetry.
    1. Warning: The Renderer currently only draws UTM rasters properly[1] . So if your raster is in Geographic projection (lat/lon) as it may well be if you just took the raster data tutorial and imported some Kauai data, you first need to re-sample it to UTM, and there is a re-sampling tutorial for that.
    2. (Once you have a UTM raster,) Select the 'Raster' tab
  4. Make some Terrain corresponding to the Raster (Unless this RasterData has been rendered before it probably doesn't already have Terrain associated with it).
    1. Click the 'Make Terrain' button.
      1. Navigate to the RasterData TRA file that you want to open[1]
    2. If your RasterData is already open within Tarsier:
      1. Select the drop-down arrow on the UseeControl
      2. Select your raster from the list of currently open rasters
    3. Hit OK to confirm that you want to make some terrain tessellation files (a bit like pyramid files in ArcMap)
    4. Hit OK to confirm that you want to use the suggested TRNTI file name in a 'terrain' sub-folder within the folder where your raster resides.
    5. If your raster is very large (millions of pixels), you might have to wait several minutes it to make the terrain tessellation.
    6. A message will come up asking if you want to put a color raster on top of your terrain. Click 'Yes'.
    7. A 'usee' dialog will come up. Select the raster you want to put on top, usually a true-color raster or the raster you used to make the terrain.
    8. Click 'Ok' once you select your color raster.
  5. Enable the Raster
    1. Click the Check Box at the top-left of the Raster tab
  6. Point the camera at the terrain
    1. Select the 'Cam1' tab
    2. Click one of the three buttons with a picture of a camera (middle-left)
    3. You should see your raster
      • On Aspen IV terrain does not show up until terrain loaded into raster 2 tab
  1. Change the color of your raster
    1. Its probably pink right now, which denotes 'NoData' - referring to the fact that you probably haven't selected a raster for it to use in deciding what color to render the terrain (as opposed to the 'Relief' raster that you used to specify how high to draw the terrain)
    2. Go back to the 'Raster' tab
    3. In the 'Raster' UseeControl, select the same raster that you are using for the Relief
    4. The raster should now look colored according to elevation (and shading due to different sun angles on the terrain)
    5. To change the color scheme, click the 'C' button, then select 'Custom' and 'Rainbow' (if its not already set to this)
    6. You should see different colors on the raster now
      1. You may need to select a different option for Color scheme (such as RGB) and re-select Custom for the colors to change - Briano 20:16, 19 March 2009 (UTC)
  2. Change the level of detail
    1. Your raster might look a bit blurry, this is to make the rendering fast. You can add detail at the expense of speed as follows.
    2. Select the 'Econ' tab (it stands for 'Economy' i.e. being efficient)
    3. Type '20' in the 'Detail' box (the default is 5)
    4. Type 'TAB', or click somewhere outside the box to get it to accept this value (the need for this is related to another Tarsier bug)
    5. Go back to the 'Raster' tab and disable then re-enable the Raster (this is only needed because of a minor refresh bug)
  3. Fly around your terrain
    1. Click 'Keys' on the 'Cam1' tab
    2. Type 'm' to select the view vector instead of the movement vector
    3. Use the arrow keys: left, right, up, down
    4. For more advanced flying see Tarsier: Renderer flight controls

What else can I do in a Renderer View?

I have more raster data

  1. Add up to two more raster data sets using R2 and R3 tabs
    1. overlapping data will be visible according to the raster tabs
    2. adjust your data in the tabs according to your visualization needs

My color scheme looks ok, how can I make it look better?

  1. Go to the "Sun" tab
  2. Auto set sun position and light to adjust to the time of your visualization


  1. Manually adjust the position of the sun
    1. Elevation: colors will apear brighter when the sun is higher in the sky
    2. Azimuth: features in your DEM with different strikes will be highlighted as the sun is shining from different directions
  2. Manually adjust the RGBs (primary colors... red, blue and green) of your data
    1. Sky: sets the color of the sky
    2. Ambient: visibility of the data not dependent on the sun settings
    3. Diffusion: this essentially adjusts the blending of colors

How much of the horizon do you need to see?

  1. Go to the "Frus" tab
  2. "Near" distance is the data that will render closest to the camera
  3. "Far" distance is the data that will render within that set sidtance from the camera
  4. Flying will be quicker with fewer data to render
  5. If time is not limited, like dirring flight recordings, set max near and far

What else will improve my picture quality?

  1. Go to the "Gen" tab
  2. Increase "Accululations" will give you a sharper image
  3. It will also take longer to render
  4. Be mindful of what you need

lots more coming soon...

Saving a Renderer

  1. In general, saving files in Tarsier is idiosyncratic, as described here.
  2. When saving a Renderer, you are prompted with about 20 or 30 dialog boxes! Which one's should you save, and which ones should you cancel (ESC)?
    1. Select File --> Save As
    2. Look in the heading of the dialog box, and in the 'Save as type' box to see what's being saved
    3. For each of the following file types, save the file name listed along with it:
      1. TRC: save as render.trc
      2. TRG: save as render.trg
      3. TRX: ignore for now, type ESC
      4. TGT: ignore for now, type ESC
      5. TRA x many: ignore for now, type ESC
      6. TRNTI: ignore for now, type ESC
      7. TRNTI x 3: ignore for now, type ESC
      8. TSD x 3: ignore for now, type ESC
      9. TNE: ignore for now, type ESC
      10. TGU: ignore for now, type ESC
      11. TVS: ignore for now, type ESC
      12. TRD: ignore for now, type ESC
      13. TRI: save as render.tri
      14. TDO: ignore for now, type ESC
      15. TDL: ignore for now, type ESC
      16. TRE: save as render.tre (this is the main one, that you can later open to open the whole Renderer)
  3. Check that what you did works, by closing everything, and re-opening the TRE file (render.tre)

It doesn't matter if you call the files render.tre or something_else.tre. But calling them render.tre makes it easier to keep them in one place and know what they are.

Take a screen grab of your work

  1. Open a Renderer (it must be named)
  2. Select the 'Rec' tab
  3. Click 'Grab one frame at 16 accums'
  4. A file named 'Grab_*.jpg' will appear in your working folder. Email it to impress your friends.

Notes and references

  1. 1.0 1.1 Tarsier used to draw UTM rasters just fine, but when the terrain tessellation system was implemented (to handle very large rasters), the ability to tesselate lat/lon rasters was left behind. At present, the tesselation and rendering code attempts to handle lat/lon rasters, but the results are flawed

Who has taken this tutorial?

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

  • Nick M
  • Brian
  • Alberto
  • Jonathan
  • ryanf
  • Pam K-D