[vtkusers] Rendering speed when using text labels

[David E DeMarle]

In order to combat the screen clutter and keep rendering speed acceptable,
you could programatically do a full screen visible cell selection after each
still render just to figure out the number of visible cells. When the number
is some small fraction of the number of pixels available turn on the
labelling.

cheers
Dave DeMarle


On 8/27/07, Charl P. Botha <cpbotha at cpbotha.net> wrote:
>
> You should also try switching on ImmediateMode rendering for the
> labels.  By default displat lists are used (afaicr) and at least on my
> hardware, rendering new geometry takes painfully long.  This might
> solve your problem with slow switching off/on of the labels.
>
> On 8/27/07, David Goldsmith <David.L.Goldsmith at noaa.gov> wrote:
> > "That would help for the nifty spinning around and all, but we found
> > that  it's painfully slow even when you just do one action, and then
> > wait for it to re-draw. At least that's what I thought we were seeing."
> >
> > "Turning labeling on/off during rendering process ... looks like it
> > shouldn't help - if you remember, it takes [a lot of] time to turn on
> > [such a] large number of labels.  So it [seems like it would] change
> > nothing - on 'turn labels back on' vtk will start [the] rendering
> > process for the labels [and]
> > we approach the same problem [we are having]."
> >
> > DG
> >
> > David E DeMarle wrote:
> > > Hi David,
> > >
> > > Have you tried turning off labels while camera manipulation is
> > > happening and turning them on only after a still render?
> > >
> > > hth,
> > > Dave DeMarle
> > >
> > >
> > > On 8/25/07, * David Goldsmith* <David.L.Goldsmith at noaa.gov
> > > <mailto:David.L.Goldsmith at noaa.gov>> wrote:
> > >
> > >     Thanks for your reply, Berk.  We've thought of that -- you're
> quite
> > >     right that 1000 labels is pretty useless. However, we need an
> > >     efficient
> > >     way to turn the labels on and off for our use.  For example, we
> > >     may have
> > >     10,000 points, each with one or more value(s) associated with
> it.  Our
> > >     users want to see these values without having to select the points
> or
> > >     triangles (in our application, that's gonna get awfully
> > >     tedious).  When
> > >     all 10,000 points are visible, they're so close together that
> there is
> > >     no point, but when the user zooms in to get a closer view, and can
> see
> > >     perhaps 100 points, we'd like the numbers to show up next to the
> > >     points
> > >     automatically.  How might one accomplish that?  Thanks again!
> > >
> > >     DG
> > >
> > >     Berk Geveci wrote:
> > >     > In paraview, we decided to only show labels of selected
> cells/points
> > >     > to overcome this issue. I don't think showing more than a few
> dozen
> > >     > labels makes much sense anyway.
> > >     >
> > >     > -berk
> > >     >
> > >     > On 8/24/07, David Goldsmith <David.L.Goldsmith at noaa.gov
> > >     <mailto:David.L.Goldsmith at noaa.gov>> wrote:
> > >     >
> > >     >> Hello!  We're using vtk for 3-D traingular mesh
> visualization.  To
> > >     >> number label the points in the visualization, we're using
> > >     >> vtkLabeledDataMapper.  We're finding, however, that labeling
> > >     even on the
> > >     >> order of only 1000 points significantly slows down all
> > >     rendering.  Any
> > >     >> suggestions for how to speed things up would be greatly
> > >     appreciated.
> > >     >> Thanks!
> > >     >>
> > >     >> DG
> > >     >>
> > >     >> --
> > >     >> ERD/ORR/NOS/NOAA <
> > >     http://response.restoration.noaa.gov/emergencyresponse/>
> > >     >> _______________________________________________
> > >     >> This is the private VTK discussion list.
> > >     >> Please keep messages on-topic. Check the FAQ at:
> > >     http://www.vtk.org/Wiki/VTK_FAQ
> > >     >> Follow this link to subscribe/unsubscribe:
> > >     >> http://www.vtk.org/mailman/listinfo/vtkusers
> > >     <http://www.vtk.org/mailman/listinfo/vtkusers>
> > >     >>
> > >     >>
> > >
> > >     --
> > >     ERD/ORR/NOS/NOAA
> > >     <http://response.restoration.noaa.gov/emergencyresponse/>
> > >     _______________________________________________
> > >     This is the private VTK discussion list.
> > >     Please keep messages on-topic. Check the FAQ at:
> > >     http://www.vtk.org/Wiki/VTK_FAQ
> > >     Follow this link to subscribe/unsubscribe:
> > >     http://www.vtk.org/mailman/listinfo/vtkusers
> > >
> > >
> >
> > --
> > ERD/ORR/NOS/NOAA <
> http://response.restoration.noaa.gov/emergencyresponse/>
> > _______________________________________________
> > This is the private VTK discussion list.
> > Please keep messages on-topic. Check the FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> > Follow this link to subscribe/unsubscribe:
> > http://www.vtk.org/mailman/listinfo/vtkusers
> >
> _______________________________________________
> This is the private VTK discussion list.
> Please keep messages on-topic. Check the FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20070828/c8d9642d/attachment.htm>