Please excuse my resending this. I'm not sure the first email got
through to the list. Thanks for your help! -Daniel
------------
Hi,
I've search the OpenDX reference, quick start, and mailing lists, as
well as read VIS's "Paths to Visualizations" (which is quite helpful),
but cannot find any guidance on this matter.
I want to translate (or copy--which is just a tranlate then collect
original plus translated) a data field, with regular cubic positions
and connections, by the size of my bounding box to better visualize
my system which physically has periodic boundary conditions.
I can think of two easy ways to do this:
1. Mark ("positions"), Compute, Unmark ("positions")
2. Translate module
The big problem with both of these (which I had hoped the Translate
module would fix, even if Mark-Compute did not, due to Translate's
more specific function), is that the connections are broken across the
border between the old and the new data set (at the periodic boundary
condition). This is easily seen with the ShowConnections module.
(For the next few days, I'll leave a demo of this exactly at:
http://www.physics.cornell.edu/~freedman/OpenDX/pbc.png)
The greater difficulty with this, of course, is that a subsequent
isosurface across the periodic boundary condition shows a noticeable
and detracting void, where the missing connections should exist.
I'm actually quite surprised not to have come across additional
references to this scenario, as (at least from my vantage point) it
appears quite common and the solution seems non-obvious to me.
I'd appreciate if folks have guidance either on how to properly
translate to handle the connections across the PBC, or to also
Mark-Compute on the connections field to similarly translate them
(it's not clear to me how to operate on the mark'd connections product
mesh to get it to Do the Right Thing). It seems to me that explicit
creation of the connections field, via a Regrid module, would be quite
cumbersome and inelegant.
Thank you kindly for any guidance,
Daniel
--
Daniel A. Freedman <[EMAIL PROTECTED]>, Graduate Fellow
Electronic Structure Calculations, LASSP, Cornell University
