VISITview Real-time Collaborations

updated: 04/21/2005

Here we describe the steps needed to set up a VISITview real-time data collaboration site. Once you've done this, groups of users may independently use your site to view and manipulate and talk about real-time images that you provide.

Temporary collaborations

If you are setting up a temporary collaboration, then here's all you need to do:

  1. Use the VISITview Lesson Builder to make your lesson (see last section, below)
  2. Make a directory for your lesson files
  3. Unzip your lesson's ZIP file into this directory

Starting the server for temporary collaborations

If you are creating a temporary collaboration and not using a machine with an HTTP server running, you may use the command:

from within your lesson directory. This will start a small, read-only Web server, plus the VISITview server. This should only be done from within the directory where your lesson is stored!! Finally, in this case the so-called "alternate HTTP" port, 8080, is used. Therefore, you will need to tell your collaborators to use the following URL to join the collaboration:

When you've finished with the temporary collaboration, close the window where you started the Httpd server so that the server will stop running.

Semi-permanent collaborations

If you are planning to create a semi-permanent collaboration, then here's what you need to do:
  1. If your collaboration is to be semi-permanent, then pick a machine that has an httpd server on it
  2. Install the Java Runtime Environment appropriate for your platform (info available from Unidata) and besure the java is in your PATH.
  3. In your account (or make up a new one for this purpose) make a directory to keep the VISITview software. Get the file and unzip it in this directory.
  4. Finally, make a directory to hold your lessons that is accessible to users through the httpd server. In some cases, this might be a sub-directory of one named public_html/ or htdocs that already exists and is a starting point for the web server.

Starting the VISITview server

You base directory is now set up to run the VISITview server and to put in your "lessons" (which will actually be links to real-time data). Our suggestion: if you normally think of making your data available as sets of animations, then define each set as a VISITview lesson "page". To start the VISITview server, enter the command:
       java -cp ./ ViewServer
if you want to keep the logging information, then re-direct the output into a file. For example:
       java -cp ./ ViewServer >serve.txt 2>&1
Note: if you're using Java version 1.0 or 1.1, the java command should be replaced by the jre command. Also note that on Windows computers, the "/" should be "\".

Automatically starting a VISITview server

If you want to keep a VISITview server running, you can follow the instructions for Windows by clicking here, or for Unix by clicking here.

Making your "Lesson"

Use the VISITview Lesson Builder to create your lesson, or hack one of the examples available. Important -- if you plan to use web browsers for this collaboration (most common), then be certain that you do not specify a "host" parameter for the server, or that it be the actual host from which the lesson will be served. (You may also edit the 'viewmaster.html' and 'viewstudent.html' files manually are remove this parameter.)

When the Builder is done, it saves everything needed into a ZIP file.

Create a subdirectory to contain your "lesson" files which is acsessible to users via the httpd server. Just unzip the ZIP file you just created into this directory and you're off and running.

If you will be updating the images (for example, using near realtime images), you might find using symbolic links to your images is much more convenient than trying to update the HTML everytime you add new images to your pages. With symlinks, the HTML can remain static.

Note that in collaborations, generally no group is defined when saving your lesson in the Lesson Builder. When this is done, the client initially asks the server for a list of all 'public' groups. This list is then presented to the user who may pick one from the list, or type in the name of a new group. In this way, several groups can be using the same server at the same time without interferring with each other!

If you want to define a group, however, when you use the Lesson Builder, this will keep your collaboration "private".

If you are using real-time data, then make your lesson using a sample of the images. We have found it is easiest to then use symbolic links from the names that VISITview uses for the image files to the actual image files. You can then re-assign the links or simply replace the image files as new data becomes available.

The Lesson Builder, creates image filenames in the form of: mynameV0010 (the encoding that follows the "V" is: pppf, where 'ppp' is the page number and 'f' is the frame. mynameV0113 means page 11, frame 3. mynameV01237 means page 12, frame 37 (note that in collaborations, you really should limit the number of frames to avoid problems with inconsistent down-load times...37 is way too many ;-)

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