[vtkusers] Re: Re: [vtk-developers] vtkContourWidget -- how to display 'off-plane' contours?

[dean.inglis at camris.ca]

Hi Kent,

Im not aware of a filter per se, but most
vtkCell types have IntersectWithLine, so you
could rep a plane as a vtkPolygon (a cell)
and then iterate over the point pairs making
up the contour and check for intersection.

Dean

> Subject: Re: [vtk-developers] vtkContourWidget -- how to display 'off-plane' contours?
> 
> See, now that is why they pay you the big bucks, Dean!  I actually use
> the ContourAsPolyData thinger to build a binary image from the contour
> collection I build, but didn't think of it in this context.
> 
> I can certainly iterate through the points and find plane
> intersections myself, but is there a VTK class or filter that will do
> it for me.  I may not be the smartest tool in the shed, but I have
> been looking through the documentation and not seeing anything
> obvious.
> 
> On Tue, Feb 12, 2008 at 3:13 PM,  <dean.inglis at camris.ca> wrote:
> > why do you have to do anything with the contour
> >  rep?  Why not just get the polydata from the
> >  rep (GetContourRepresentationAsPolyData) and find
> >  the intersection of that with whatever plane?
> >
> >  Dean
> >
> >
> >  > Subject: [vtk-developers] vtkContourWidget -- how to display 'off-plane'
> >  >       contours?
> >
> > >
> >  > As long as I'm asking hard questions, consider this scenario.
> >  >
> >  > My application maintains 3 orthogonal views of the same volume:
> >  > Sagittal, Axial, Coronal.
> >  >
> >  > The advantage of using VTK is not having to write all the code that's
> >  > already in VTK.  The disadvantage is that if you want to do something
> >  > not currently done in VTK, you have to crack open a bunch of 'black
> >  > boxes' and monkey around with the spaghetti wiring inside.
> >  >
> >  > Our old tracing application let you trace on one view (e.g. Sagittal),
> >  > and in the other 2 views, it displayed the intersection of all the
> >  > traced contours with the image plane of those other two views.
> >  >
> >  > So I'm in the unenviable position of cracking open the
> >  > vtkContourRepresentation, and somehow finding the intersection of the
> >  > contour and the plane of an orthoganal view, and then show the
> >  > intersection.
> >  >
> >  > So I guess my question is this: How would I do this the VTK way?
> >  > _______________________________________________
> >  > vtk-developers mailing list
> >  > vtk-developers at vtk.org
> >  > http://www.vtk.org/mailman/listinfo/vtk-developers
> >  >
> >
>