[quote]The problem is that random groups of vectors pop up in random locations in the field and then quickly disappear throughout the simulation. [/quote]

I did not find the above problem with my computer (Firefox running on Window Vista).
The differerce between old and new vectorField3D is the data structure.
I believe the code to draw all the vector fields are the same.
I was wonder why there is a TraceSet in your code (n elements and x,y,z properties were not defined?)

May I know what kind of simulation you were trying to create? May be there is a better way to make a simpler visualization effect. The current GUI seems to be too complicated to me. Do you really need to show all vectors fields (filled most of the simulation region)?