Hey All,
I'm not sure if John has it exactly right, but he may not be that far
off...
I was working today on a variant of the Clip filter which would not
remove coincident points, and somehow in my ServerManger XML I ended
up always exposing the Scalars input combo-box (which is used as input
to vtkClipDataSet::SetInputArrayToProcess()) no matter whether I was
clipping by plane, box, sphere or scalars. By default, vtkClipDataSet
uses the active scalars on the first input for this array -- but using
this combo box I could control this input even though I wasn't really
"using" it (because I was clipping with a box or a plane).
The clip filter always keeps all the scalars from the block which
contains the input to SetInputArrayToProcess(). The filter loses data
from the other block, and it always seems to be the most recent array
added to that data set -- i.e. the one which should be the "active
scalars" in that block. This agrees with the behavior seen in my other
examples in which the "second" data set highlighted before the Group
filter is the one that loses a data array -- the active scalars of the
first selected block are probably the ones being used for
SetInputArrayToProcess().
I can't track it down to the type of SetActiveScalars() without a call
to AddArray() that John is talking about, but it seems related since
it is the "active" scalars that are getting lost.
If you think this is intelligible at all, I can add it to the bug
report.
Talk to you later,
-Eric
On Feb 6, 2009, at 9:38 AM, John Biddiscombe wrote:
Eric et al,
I recently had a problem where a filter opreated normally when used
normally, but when someone put a calculator in front of it, it
stopped working. The filter in question instantiated other filters
internally.
I tracked to the problem down to this.
Calculator calls SetActiveScalars(New data)
another filter later does a PointData()->PassData(blah)
->SetActiveScalars(More New data)
And the New data from before was lost. I do not like this
SetActiveScalars function because it replaces (not adds) whatever
scalar was there before. I cnaged the offending filter (in this case
vtkSurfaceVectors) on my copy to do
PointData()->PassData(blah)
PointData()->AddArray(newData);
PointData()->SetActiveScalars(newData->GetName())
or something like that (from memory).
I have no idea if this is related to your problem, but I just
thought I'd vent my spleen and start a campaigh to remove this
SetActiveScalars(...) call as it is just rubbish. (At least it
should be modified internally to not remove the old active slalars
if they are are about to be wiped)
JB
Hey Utkarsh,
No, I've never seen the clip lose data on one dataset by itself.
The other interesting thing is that I can't always get this data
loss to happen if the data was generated as part of a source from
the Sources menu. It's much more likely to disappear when the data
was generated by a filter or brought in by a reader.
For example, if you generate a Box and a Wavelet source, grouping
and clipping them won't lose any data, but if you run Generate IDs
on one of them, then select GenerateIds1 second before grouping,
then clip, the "Ids" point data disappears...
Thanks,
-Eric
On Feb 6, 2009, at 7:37 AM, Utkarsh Ayachit wrote:
Eric,
Does the loss of arrays happen even if you clip the orginal
dataset by
itself (without grouping it using the group filter)?
Utkarsh
On Wed, Feb 4, 2009 at 3:53 PM, Eric E. Monson
<[email protected]> wrote:
Hello,
I'm creating a multi-block data set using the group filter and
then clipping
it. The results of the clip are always missing one of the scalars
associated
with the second data set that I highlighted before applying the
group
filter. This only seems to happen if one of the data sets has
multiple
scalars or vectors associated with it -- if they each only have
one, nothing
is lost in the clip. (ParaView 3.4 and CVS, OS X 10.5.6 and
Windows XP
32-bit, no MPI)
I originally saw this with my own data, but I am able to easily
replicate
this by creating two point sources. I apply the Elevation filter
to the
first. Then, to the second I apply Brownian Vectors, plus a
Calculator that
computes the magnitude of those vectors. If I highlight Elevation
and then
Calculator, then Group and Clip, I lose the vector magnitude
scalar at the
Clip stage. If I highlight the Calculator and then the Elevation,
then Group
and Clip, I lose the elevation scalar.
Please let me know if anyone has any ideas about where this could
be coming
from.
Thanks a lot,
-Eric
------------------------------------------------------
Eric E Monson
Duke Visualization Technology Group
_______________________________________________
ParaView mailing list
[email protected]
http://www.paraview.org/mailman/listinfo/paraview
_______________________________________________
ParaView mailing list
[email protected]
http://www.paraview.org/mailman/listinfo/paraview
--
John Biddiscombe, email:biddisco @ cscs.ch
http://www.cscs.ch/
CSCS, Swiss National Supercomputing Centre | Tel: +41 (91) 610.82.07
Via Cantonale, 6928 Manno, Switzerland | Fax: +41 (91) 610.82.82
_______________________________________________
Powered by www.kitware.com
Visit other Kitware open-source projects at
http://www.kitware.com/opensource/opensource.html
Please keep messages on-topic and check the ParaView Wiki at:
http://paraview.org/Wiki/ParaView
Follow this link to subscribe/unsubscribe:
http://www.paraview.org/mailman/listinfo/paraview
