Dept of Commerce / NOAA / OAR / ERL / PMEL / TMAP /

Introduction to Vis5D

This document will give an overview of starting up Vis5D and using its basic capacities to view a Vis5D-formatted file. It is intended for Ferret users who use Ferret external functions to write gridded data to Vis5D-formatted files.

Vis5D is a public-domain graphics visualization program developed at the University of Wisconsin-Madison Science and Engineering Center by Bill Hibbard, Johan Kellum, and Brian Paul. The software package and documentation can be obtained from the Vis5D web site.

Vis5D is a tool for interactive visualization of gridded data sets in 5 dimensions: 3 spatial dimensions, time, and a variety of physical variables. From Ferret, we can write data to the Vis5D file format by calling the external function writev5d.F, or via the GO script wv5d.jnl which calls the external function. The document Writing Vis5d files from Ferret will show you how to create the files. If you have the Vis5D README file, the Ferret external function takes care of section 3, "Putting your data into Vis5D". This document summarizes the main elements of the README section 6. "Using Vis5D to Visualize Your Data"

Vis5d data files have the extension .v5d. To view one, issue the command: 

vis5d  filename.v5d   [options]

Or from within Ferret, 

GO vis5dstart  [filename.v5d]    which defaults to file vis5d_out.v5d

There are a number of command-line options available. None are needed, but among them are two which may be useful as you get started:

-date
Displays the date as 'dd month yy' rather than 'yyddd'
-trajvars uvar vvar [wvar]
Specify variables to be used for trajectory traces. The defaults are U, V, and W.


The vis5d command starts two windows on your screen; a control panel with buttons to make choices about the Vis5D session, and a 3-D display window. The control panel has these sections:

  1. The top section contains buttons to control the overall functions of Vis5D. Here are a few you will need for many Vis5D sessions.

    ANIMATE and STEP
    For data with time steps, these allow you to step through or animate the data. If the data set has only one time step, these buttons are blank.
    TOP, SOUTH and WEST
    View data from the top, from the south, or from the west; helpful in orienting yourself after rotating the data viewing box.
    MAP
    Shows outlines from the map file; a default map is included with the Vis5D distribution files.
    REVERSE
    Changes the background from black to white; useful if you plan to save an image to a file.
    SAVE PIC
    Saves the image in the 3-D window to a file. A window appears in which you choose the file format and name.
    EXIT.
    (at the upper right) Close Vis5D.

  2. The middle section of the control window contains buttons to control the viewing mode. To the right of these buttons is a display that shows a list of the functions of the mouse buttons in the viewing mode which is in effect. Two modes to get you started are:

    Normal
    The initial setting, in which the left mouse button rotates the 3-D view of the data. Hold down the left mouse button and move the mouse while in the 3_D display window to rotate the image. The middle button is used to zoom in and out, and the right button translates the plot around the display window.
    Slice
    In this mode you can reposition the location of the horizontal and vertical slices through the data. Use the right button to drag the mouse along the edge of the data viewing area to move the location of the slice.

  3. Next is a line of buttons to choose vector plotting. For instance,
    Hwind1
    Display horizontal vectors if there are variables in your file named U and V, or if horizontal vectors were specified on the command line. A control box appears if a trajectory plot is chosen, so that the scale and density of the vectors can be adjusted. To set the color of the vectors, click on the variable name with the right mouse button. A control window will appear with sliders for Red Green, and Blue. Adjust these (the button for the variable will show the color), and when done click "Close" at the top of the control window.

  4. The bottom section contains buttons with the names of the data variables. These are in six columns for the different plot types available: Isosurf, Contour Slice Horizontal, Contour Slice Vertical, Colored Slice Horizontal, Colored Slice Vertical, and Volume. Variables are listed by name under those columns for which the dimensions of the data allow that kind of plot. Click with the left mouse button on one or several of the buttons to view one or more variables. A control window for each graphic will pop up when that graphic is chosen. Some of the features of these plots and their control windows:

    Contour Slices
    The control window allows you to choose the contour interval in data units. To set the color of the contour lines, click on the variable-name button with the right mouse button. A control window will appear with sliders for Red, Green, and Blue. Adjust these (the button for the variable will show the color), and when done click "Close" at the top of the control window.
    Color Slices(Color-Filled Plots)
    The control window shows the color table and the range of data values. The colors can be changed by dragging the left, middle, and right mouse buttons in this display to change the shape of the red, green, or blue functions. OR, you can use the keyboard arrow keys to move the whole spectrum towards blue or red.
    Isosurfaces
    An isosurface shows the 3-D volume bounded by a particular value. The control box has a slider showing the range of data values. Position it at a desired number and click "OK" to compute the isosurface for that data value and draw the plot. The color of the isosurface is chosen by clicking with the right mouse button on the name of the variable in the "Isosurf" column of buttons and adjusting the sliders in the pop-up window to the desired color.
    Volume
    Volume rendering displays a 3-dimensional field as a colored fog. The pop-up window which appears is used in the same ways as the ones for the color-slice displays, using the mouse or keyboard arrows to change the colors.
This has been just a peek into the capabilities of Vis5D. The Vis5D web site, documentation, authors, and mailing list are all resources for you to learn more about this tool and use it to understand and display your data.
Last modified: Dec 14 1998