[vtkusers] OK so does ANYONE use the vtkImageTracerWidget?

[Mark Wyszomierski]

I had a look at the code I had written, turns out I was kind of
cheating because I could never get vtkImageTracerWidget to behave the
way I expected with a 3d image volume.

What I did was made one instance of vtkImageReader2 with a depth of 1
image. When scrolling to the next image in the image series, I'd
overwrite all the pixel data. This way the tracer widget was only ever
present on the only 'image' in the viewer.

I have a test application now which just reads a sequence of images,
and I cannot get the tracer widget to draw on any other slice besides
the first one. How are you able to draw on the other slices?

In the old application I have, I am using the following to re-init the handles:

   vtkPoints* p = vtkPoints::New();
   // Fill 'p' in here with your stored handle points for the current
image index.
   m_pTracerWidget->InitializeHandles(p);
   m_pTracerWidget->Modified();
   p->Delete();

and that works ok.

I don't know if the single image at a time trick is usable for you
guys. If you let me know how you were able to draw on multiple slices
I can patch it in and put up an example,

Thanks,
Mark

On 11/2/07, jonathan grimm <flymolo at gmail.com> wrote:
> I will be doing most of the same things you talked about, but I haven't
> gotten into it yet.  As a general course when I want to greatly extend
> something from VTK, I edit the existing class making everything non-trivial
> virtual then extend the class.  This allows me to keep up to date with VTK
> fairly easily.  I haven't looked at image tracer widget yet though.  The
> application I need it for will be my first Qt application, and I'm trying to
> design the event model first.
>
> The application this program is replacing strictly marked points, leaving
> the construction of lines and surfaces to post-processing.  This approach
> has proved burdensome, and we would like to delineate surfaces (possibly
> with splines rather than lines) in the future.
>
> What is your time frame for this application?  I will probably have our
> lab's solution in a month or so.
>
>
> On Nov 2, 2007 8:01 AM, kent williams < nkwmailinglists at gmail.com> wrote:
> > A couple of days ago, I posted a note asking about image tracing using
> > vtkImageTracerWidget.  I guess it was too long or too speculative or
> > something because I got no response.
> >
> > I'm not complaining, mind you.  I know support from peers and
> > developers is voluntary.
> >
> > But since it didn't get any response let me ask a different question:
> > Has anyone use the vtkImageTracerWidget for any real application?
> >
> > If the answer is no, what did you end up doing to implement tracing?
> >
> > Right now, I've gotten as far as this:
> >
> > 1. Load a 3D Image.
> > 2. Enable tracing. Trace on that slice
> > 3. When I switch slices, save the traced points
> > 4. When I switch back to a slice I've already traced, restore the saved
> points.
> >
> > What isn't happening right now: If I switch to an untraced slice, I
> > call InitializeHandles() with a zero length set of points, but this
> > doesn't in fact get rid of the currently visualized trace.
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>
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