[vtkusers] 3D from image slices taken at regular angles?

[David Gobbi]

Hi Greg,

Another approach would be to use vtkImageReslice to extract images at
the appropriate angles, then use those images as textures on a series
of radially arranged planes.  Do properly display using transparency,
the size across each image will have to be equal to the radius of your
'air filter' rather than the diameter and the planes would have to be
sorted back-to-front.

This would require one vtkImageReslice object per extracted slice,
and you would either have to sort the actors yourself before each
render or collate the outputs from each vtkImageReslice into one
huge texture and append all the actors together into one actor,
and then appropriately set up the texture coordinates to map the
correct part of the texture to each rectangle.  Once everything is
set up as one actor, vtkDepthSortPolyData can be used to sort the
planes back-to-front.

 - David

--
  David Gobbi, MSc                    dgobbi at irus.rri.on.ca
  Advanced Imaging Research Group
  Robarts Research Institute, University of Western Ontario

On Sun, 10 Nov 2019, Will Schroeder wrote:

> Hi Greg-
> 
> As a first cut you might try vtkStructuredGrid. This is topologically regular
> (as you described) but requires geometric coordinate specification. This will
> take care of the representation.
> 
> Rendering with transparency is a little trickier. One approach would be to
> resample on a volume, and then volume render that. Another is to generate
> a series of cut planes (like in the example graphics/examplesTcl/combVol.tcl).
> If you are real ambitious, you could write a filter that extracted planes from
> your radially structured data in sorted order (sorted along the camera view
> from back to front) and then render that. (Sorting is required to insure
> correct compositing / alpha blending).
> 
> Will
> 
> At 04:43 PM 11/9/2000 -0700, you wrote:
> 
> >I have obtained a number of images of an object during rotation of that
> >object about its long axis (or rotation of the imaging device).
> >
> >The result can be envisioned as the air filter or oil filter in your car -
> >a series of 2D images radiating from a common central axis at regular
> >angle intervals. In another example, the images are like a deck of cards
> >set on their side and then fanned around the centre axis like spokes in a
> >wheel.
> >
> >To recreate the object in three-dimensions and be able to view it with
> >varying transparency levels, I would like to organize the seperate images
> >in what I imagine would be a "circular stack" in comparison to the linear
> >stack currently available.
> >
> >Can this be performed in VTK? Thanks in advance.
> >
> 
> 
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