[vtkusers] Drawing Lots of geometry..

[Kalpathi Subramanian]

I am working on an application to display lots of synaptic 
connections between pairs of neural
populations.  We represent a population using a 2D lattice 
(currently 10x10 uniform grid) and connections are
line segments.  As this is part of a simulator, the 
connections change at each time step of the simulation. 
Connections
are 1 to many --- i.e. a neuron can connect to multiple 
targets in the target population.
When there are very few connections, then rendering these as 
individual line segments is not a problem. But
wnen the populations are over driven, then  potentially 
each  neuron can connect to almost all of the target
cells, thus in the worst case, you can have 100*100 = 10,000 
connections. These will change from one time
step to the next.. a very dense visualization.

Thus having individual actors for each synapse is too slow. 
I am trying to see what will be an efficient way
to render these with minimal number of actors.  I thought of 
taking all connections from a source neuron
to its targets (can be up to 100) and drawing that as 1 
polyline ( the polyline will have to come back to
the source neuron each time from the target -- thus you draw 
twice the number of needed line to keep
the integrity of the polyline); and then put this together 
as part of a vtkUnstructuredGrid.  I was thinking
of  some clever way to index it with point ids (the source 
or target points -- coordinates --  dont change or move)..

Is there a better way? Dont know enough about the internals 
of VTK.. basically need an efficient way to draw lots of
line geometry, while still taking advantage of the 
infrastructure of VTK.

Thanks.

              -- krs

-- 
_______________________________________________________

K.R.Subramanian                      Phone: (704) 687-8579
Assoc. Professor, Computer Science   FAX:   (704) 687-3516
UNC Charlotte, Woodward 435E         Email: krs at uncc.edu
Charlotte, NC 28223-0001             www.cs.uncc.edu/~krs
-----------------------------------------------------------
If you are not the intended recipient of this transmission or a person responsible for delivering it to the intended recipient, any disclosure, copying, distribution, or other use of any of the information in this transmission is strictly prohibited. If you have received this transmission in error, please notify me immediately. Thank you.