Sean,
Thanks so much for your quick reply!  

A quick question regarding our options at this point:

My team needs to have a visualization of this system soon, is this same
bug found in the 2d network or is it just in the 3d network? 
If not, it shouldn't be too much effort to temporarily use a 2d
visualization instead of the 3d one. 

Let me know if you make any progress with the 3d network bug or if I can
help in tracking it down. 

Thanks again for your help,

Jesse 

-----Original Message-----
From: MASON Multiagent Simulation Toolkit
[mailto:[log in to unmask]] On Behalf Of Sean Luke
Sent: Wednesday, June 04, 2008 2:10 PM
To: [log in to unmask]
Subject: Re: 3d Edge Portrayal Problem

On Jun 4, 2008, at 1:27 PM, Jesse St. Charles wrote:

> First -
> When the simulation is running, the network object is being updated
> correctly however the edges that are being visualized seem to only be
> edges which were present when the simulation began (some type of edge
> portrayal update problem?).

This is, I think, a bug -- or rather, some missing code -- in MASON's  
NetworkPortrayal.java code.  We'll get back on that.

> Second -
> After some time running the simulation for a given (not consistent)  
> number
> of generations I recieve this error
>
> Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
>  at sim.portrayal3d.network.SimpleEdgePortrayal3D.getModel
> (SimpleEdgePortrayal3D.java:129)

This is probably related to the above.  My hypothesis:

1. You created some edges.
2. MASON displayed those edges.
3. You deleted an edge.
4. MASON isn't removing that edge.  Rather, it's holding onto the old  
displayed edge.
5. You deleted one of the objects the phantom edge is pointing to  
(say, the start object).
6. When MASON needs to update the phantom edge, it goes in and asks  
for its start and end objects.
7. Then it requests the location of the start object.
8. MASON politely says: "there's no such object any more!"

That's what I'm going on.

Sean