Digital Earth > Terravision^TM > User Guide > Tcl/Tk > Debug Menu

The Debug Menu

Debug Level

TerraVision^TM is an extremely complex application and it is often useful to know what it is doing at certain times. The debugging facility makes TerraVision^TM output a stream of diagnostic information to the shell window that it was run from, or to a file on disk. TerraVision^TM supports a number of levels of debugging output from Level 1 (most terse) to Level 4 (most verbose). This option is primarily available for the developers to effect debugging of the application.

Debug Masks

In addition to setting the verbosity of debug output that would like, you can also restrict the debug output to specific areas of the TerraVision^TM system. These areas are defined below. It is also possible to select whether you would like debug output to go to the console (not applicable under Windows) or to a file on local disk.

1. Tiles - the requesting and reading of tile data from the remote dataset.
2. Texture - the management of the texture cache
3. Initialization - initialisation routines
4. Visibility - the scene visibility calculation
5. 2-D Viewer - the management of the 2-D (overhead) viewer
6. 3-D Viewer - the management of the 3-D (out the window) viewer
7. Map Viewer - the management of the Map window
8. OpenGL - the major graphics functions
9. OAA - Open Agent Architecture messages
10. Logging - Diagnostic logging debug messages
11. Cache - Tile and texture-map cache status
12. .geo - the .geo discovery diagnostics

Debug Settings

• Freeze Tiles -- for every frame, TerraVision works out the smallest subset of tiles that it requires for that viewpoint by culling against the view frustum and employing lower resolution tiles farther from the viewer. This option let's you freeze the tile selection that TerraVision made for a particular view. You can then fly around and examine this tile subset to see how TerraVision performs its optimizations. It is useful here to turn on the view frustum display and the tile bounding boxes via the Link menu.

  The "Return to Frozen View" button will reset the viewpoint to the location and orientation when you turned the Freeze Tiles feature on.

• Debug HUD -- The Heads Up Display (HUD) provides a textual overlay in the bottom-left corner of the display with various useful pieces of information. There are two HUD modes, debug and normal. The debug mode provides a lot more information, while the normal mode provides a more concise readout. The following information is displayed in the debug HUD, with only the first two items being shown under normal circumstances.

  • The (latitude, long, elevation) of your viewpoint

  • Your (yaw, pitch, roll) orientation

  • The effective near and far clipping planes.

  • The current frame number and the number of tiles in the scene

  • The 1 second data burst rate into the application (MBit/s) and the total amount of data read so far

  • The frame rate of the graphics system (instantaneous and averaged over 5 second)
  

• Debug Tiles -- this option will display a wireframe overlay over every tile in order to show the polygonal structure for each tile. The colour used for each adjacent tile is changed in order to show tile boundaries more clearly. Also, a different pair of colours is used for tiles at different resolution.

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Last updated: Friday, 09-Mar-2001 16:02:52 PST.