G3 - 3d Visualization for ELCIRC [DRAFT]

G3 provides visualization support for data generated by the numerical model ELCIRC. G3 uses the Visualization Toolkit for graphics and Microsoft's MFC library for the user interface and is written in C++. G3 is currently in an alpha test phase and known to be unstable. The following is draft documentation.

System requirements:

Windows 2000/XP, a reasonably fast graphics card such as an NVidia GeForce2 with 32 MB of graphics memory and accelerated 3d graphics. 256Mb memory and several GB of disk to hold the large data files ELCIRC generates. G3 works entirely in memory so more memory would be required depending on the size of the input grid and length of the generated data. G3 has not been tested on any other Windows operating systems.

Guide to menus and popups:

Screenshot of G3.


Also in the file menu are the list of recently read background grids this should work.


Transects, isosurfaces, and levels.


Zoom of area at the mouth of the Columbia River.


Animation controls. On the toolbar From left to right:
See 'Guide to Use' below for helpful hints on generating animations. A sample animation (WARNING, 8MB AVI file): Display vertical profiles of velocities+transect in the channel using G3.

Navigation and keyboard controls:

From the VTK documentation on navigation (Note that the roller gadget on modern mice also acts as mouse button #2):

vtkInteractorStyle implements the "joystick" style of interaction. That is, holding down the mouse keys generates a stream of events that cause continuous actions (e.g., rotate, translate, pan, zoom). (The class vtkInteractorStyleTrackball implements a grab and move style.) The event bindings for this class include the following:

Zoom of transect displaying salinity and velocity vectors at the mouth of the Columbia River.

Guide to use
  1. To get started, drag 'n drop a grid onto the g3 executable.
  2. To avoid problems with navigation, zoom and translate the grid before rotating. After the area of interest is positioned, rotate, doing more zooms and translates as necessary to get the positioning right. The center of the screen is a dead zone and whatever operation has been selected will go faster or slower proportionally from the center of the display.
  3. Use View/Set Vertical Scale to scale the z-coordinates if the domain is ansitropic.
  4. The the viewpoint gets badly mangled, use the 'r' key to reset the viewpoint to include all objects.
  5. Creating an animation: As a prelimary step, stop any running animation as the load on the CPU may prevent the popups discussed below from appearing. Click on the red button on the animation toolbar. This brings up a dialog box for the output file name - give the filename the '.avi' extension. On OK, another popup will appear for selecting the format of the animation - the only one that works for sure is the "Microsoft Video 1" format. Sometimes this popup can get obscured by windows laying over the top, moving windows around may have to be done to locate the popup should it disappear.

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