Remote Visualization with Visad

Hi !

I am a beginner on Visad. I wrote several program to 3D-visualize
functions of 2 variables ( (f: (x,y) -> z ).

Now i have following question:

I want to write a Visad-Server based on Java-RMI. I want to connect
several clients to this server. Every client can set the data on the
server for his own to visualize the specific data.

I read the documentation of visad. There is a short explanation of writing
distributed visad programs based on RMI. In this example several clients
share the same data reference objects on the server. So, when one clients
want to set the data, the other clients see the changes on their displays. 
This is not what i want.

How can I write such applications ?

Thanks, Mike Wibmer