[vtkusers] Voxel Data from MATLAB to VTK

[Brian Davis]

The latest I found suports using flat arrays as you suggest and as I tried
to do and reshaping with and example I found at:

http://www.kitware.com/InfovisWiki/index.php/Matlab_Interface

The vtkMatlabMexAdapter looks exactly like what I am looking for

--snip

 edata =
vtkMatlabMexAdapter::mxArrayTovtkDataArray(const_cast<mxArray*>(prhs[0]));

   id->SetDimensions(300,300,1);
   id->SetOrigin(0.0,0.0,0.0);
   id->SetSpacing(1.0,1.0,1.0);
   id->SetScalarTypeToUnsignedChar();
   id->SetNumberOfScalarComponents(3);
   id->SetWholeExtent(0,299,0,299,0,0);

   id->GetPointData()->SetScalars(edata);

--end snip--

However a search in my tree vtkMatlabMexAdapter returns nothing.  Seems to
be a part of Titan?

Though it looks as thought it is in latest:

http://www.vtk.org/doc/nightly/html/classvtkMatlabMexAdapter.html


Brian


On Mon, May 17, 2010 at 11:25 AM, David Gobbi <david.gobbi at gmail.com> wrote:

> Hi Brian,
>
> It's much easier to use flat arrays to store n-dimensional data in
> VTK.  This is how VTK manages structured data such as vtkImageData.
> Then all you need to do when moving the data into Matlab is reshape
> the flat array into an n-dimensional array by using the known
> dimensions of the desired n-dimensional array.
>
> For example, when moving vtkImageData to Python's NumPy, I grab the
> Dimensions and NumberOfScalarComponents from the image data and use
> that information to reshape the array into a 3D or 4D array.  The same
> could be done with Matlab, I think.
>
>   David
>
>
> On Mon, May 17, 2010 at 10:15 AM, Brian Davis <bitminer at gmail.com> wrote:
> > So latest in my search for how to do this I came across:
> >
> > http://www.vtk.org/doc/nightly/html/classvtkArrayData.html
> >
> > With the important part:
> >
> > --snip--
> > Because vtkArray cannot be stored as attributes of data objects (yet), a
> > "carrier" object is needed to pass vtkArray through the pipeline.
> > vtkArrayData  acts as a container of zero-to-many vtkArray instances,
> which
> > can be retrieved via a zero-based index. Note that a collection of arrays
> > stored in vtkArrayData  may-or-may-not have related types, dimensions, or
> > extents.
> > --end snip--
> >
> > and looking at the api and input types for ImageData and the
> volumeMappers
> > the input to these appears to only be a route that involves vtkDataSet.
> I
> > get the feeling that using the Array classes in an attempt to create
> image
> > data is an futile attempt at "round hole square plug" am I correct with
> this
> > assessment?  Array data appears to have a path to filters and not image
> > data.  Is this correct?
> >
> > Which means I may have to result to awful for loops as in the examples.
> I
> > also looked at the examples for
> >
> > Brian
> >
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-- 
Brian J. Davis
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