[vtkusers] How to visualize principal components on dataset

[Dominik Szczerba]

If you have it under matlab you may try my matlab-vtk wiki and see your
data right from under matlab.

As to the example code, I just have none to do exactly what you want.
But having studied the numerous VTK examples you should be able to go as
follows: read the dataset, set up a render window, create a vtkCommand,
connect it to the interactor, in the command's Execute() method update
the contour's isovalue, update the filter and the mapper, dump a movie
frame. If what I wrote above sounds magic you will need to invest
several hours in VTK's basics before.

good luck
--DS


Arne Hansen wrote:
> Do you think you can show me an example of this?
> It would probably be best if i could save my matlab data in a vtk-file,
> and then load this.
> Do you think this is a good approach?
>  
> Thank you
> 
>  
> 2007/1/4, Dominik Szczerba <domi at vision.ee.ethz.ch
> <mailto:domi at vision.ee.ethz.ch>>:
> 
>     Oh sure it is possible. You can animate the contour moving by changing
>     the isovalue (dont forget to call Update() somewhere) and dumping movie
>     frames (I recommend ffmpeg). Just read the relevant documentation
>     (contour, movie writer). Alternatively, employ Paraview for fast
>     results.
>     --DS
> 
>     Arne Hansen wrote:
>     > Well, yes i have distance maps. But my plan is to extract only a
>     certain
>     > level of this map ie. the zero levelset. This i can do in matlab.
>     But I
>     > want to do this for a series of levelsets, since i am varying the
>     > principal modes.
>     > So I actually need to find out how i can save like a series of 3D
>     > frames, so that i can show an animation of these in VTK with an
>     > isosurface. Is this possible?
>     >
>     > Thank you
>     >
>     > 2007/1/4, Dominik Szczerba < domi at vision.ee.ethz.ch
>     <mailto:domi at vision.ee.ethz.ch>
>     > <mailto:domi at vision.ee.ethz.ch <mailto:domi at vision.ee.ethz.ch>>>:
>     >
>     >     So what is your data.
>     >     If you need to visualize different level sets of a distance
>     map then a
>     >     few contourings will do.
>     >     --DS
>     >
>     >     Arne Hansen wrote:
>     >     > Hello. I have binary shapes, which i have aligned and
>     transformed into
>     >     > signed distance maps. I have then made a mean distance map, and
>     >     created
>     >     > a set of offset functions(offset from mean). Using these offset
>     >     > functions i made a Principal component analysis to capture
>     >     variation. My
>     >     > next task is to visualize my 3D meanshape in VTK, and its
>     >     > differentprincipal modes, where i multiply from 1 to 3 standard
>     >     devians
>     >     > on each mode, to see how the shape deforms.
>     >     >
>     >     >
>     >     > Can anybody give me a hint as of how to visualize this in VTK?
>     >     > Thank you very much :)
>     >     >
>     >     >
>     >     >
>     >    
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