User's Guide to PduPlayer
I.  Requirements:

A. Hardware:

Since this software is a Java application, you can run it on virtually any hardware platform. I have tested the software for the following platforms: SGI O2, SUN ULTRA, PC - Pentium 200Mhz.

B. Software:

In order to run this application you need to have Java installed on your machine:

JDK - Java Development Kit version 1.1.5 or higher. Try this link: JAVA Products

If you want to be able to record packets originating from outside of your subnet, your machine must also be able to accept IP multicast packets. Here are some good links for informatin on joining the MBONE: the MBONE faq and Dan's Quick and Dirty Guide to Getting Connected to the MBONE .

You can run the program without MBONE connectivity. But, you can only send multicast packets inside your local subnet.

You will also need an DIS-Java-VRML application along with a VRML browser. Download the distribution file from NPS DIS-Java-VRML Distribution Page . This page has good instructions on the installation of the distribution file. It also has a link to some VRML browsers. You will be using the EspduSender and EspduReadTransformTraceExample.wrl to test this recorder.

II. Instructions

A. Setup

All necessary files should be automatically installed when you decompress the DJV build.

B. Starting the Application

To start the application go to the following subdirectory


Enter "java"

You should see the following user interface.

C. Recording Virtual Reality

You can use PduPlayer to record DJV Virtual Reality as you would use a VCR to record a television show. What you are actually doing is recording PDUs generated from one of several PDU sources such as the Capture The Flag Demo or EspduSender. If your tape is positioned before the end, you will record over the Pdu objects.

Example: Using PduPlayer with EspduSender

One way to create the DISpackets to record is to use the EspduSender applet from the Naval Post Graduate school. Once the DJV software is installed on your machine, you can launch this applet from the web browser using the folowing url:


You will see an interface that looks like this:

Make the following changes.

Choose the "File" menu from the PduPlayer application. Then choose "New". This will give will give you an empty linked list to store the DIS packets.

Next, in the filename field type the name of the file (ie record1.pdu). Next, type in the number minutes you want to record. If you want to record until you press the stop button, type in "0".

Start the AwtEspduSender applet by pressing the "Start" button for that applet.

Lastly, press the circular record button on the PduPlayer application. The botton should light up as shown below.

To stop the recording press the square stop button on the PduPlayer application. Also press the "Stop" button on the AwtEspduSender applet.

To save the file, you must choose the "File" menu and select "Save."

To save the file with another file name, use the "SaveAs" button. This will allow you to choose the subdirectory and type in the new file name.

D. Playing Back DIS Packets

1. Using your browser, go to your local copy of the examples page and click on

2. From within Cosmo Player, select the viewpoint of the entity you recorded.

3. Using the file menu of PduPlayer, open the file that contains the PDUs you recorded.

4. Press the play button (the single arrowed one).

E. Performing Rewind and Fast Forward

For rewinding, press the button with the left double arrows. For fast forward, press the right double arrows. Note that you can choose from the option menu whether or not you want the player to send pdus during either operation. If performing either of these operations during an active session, you should turn off this option. Otherwise you will get double images.

F. Clearing the Pdus

You can clear the pdus in memory by going to the options menu and selecting clear.

G. Exiting the Program

To exit the application press the "QUIT" button or select 'Quit' from the file menu.

H. Code Documentation

Documentation for the Java application was created using the javadoc utility. The documentation can be found at PduPlayer Version 2 Code Documentation

I. Source Code

The source code is included as part of the zip file. It can be found in the following subdirectory: