Ok, it seems that using vktXMLImageReader::SetUpdateExtent(int extent[6]) requires vtk 6.0 ??? Unless I am missing something, the 5.10 docs show a SetUpdateExtent() method only available in data classes (as a member of vtkDataObject) but not eg vtkXMLImageReader. I am using 5.8, but could try 6.0.<br>
<br><div class="gmail_quote">On Wed, Mar 27, 2013 at 3:38 AM, Kevin H. Hobbs <span dir="ltr"><<a href="mailto:hobbsk@ohio.edu" target="_blank">hobbsk@ohio.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im">On 03/26/2013 11:42 PM, Grant McAuley wrote:<br>
><br>
> I will look into this. However, I hope I didn't muddy the waters<br>
> by mentioning the two simulations.<br>
<br>
</div>No, all that matters is : "How does the pipeline end?" The answer<br>
for you is "you just need the data."<br>
<div class="im"><br>
> To simplify and try again:<br>
><br>
> I think all that I need to understand is how to use a reader to<br>
> read a data array in blocks - one block at a time. You mentioned<br>
> in your first reply:<br>
><br>
>>The *.vti reader, vtkXMLImageDataReader, can read the image<br>
> one requested piece at a time<br>
><br>
> That sounds exactly like what I need to know. Eg, if a DataArray<br>
> in the file has 10,000 points, I want to read 0-999, 1000-1999,<br>
> etc.<br>
<br>
</div>You need to set up the pieces the way you want them.<br>
<br>
If your image is 1D you could do exactly what you want very<br>
easily. I think something like :<br>
<br>
reader->SetUpdateExtent( 0,999,0,0,0,0 );<br>
reader->Update();<br>
whatever_you_want_to_do( reader->GetOutput() );<br>
reader->SetUpdateExtent( 1000,1999,0,0,0,0 );<br>
reader->Update();<br>
whatever_you_want_to_do( reader->GetOutput() );<br>
<br>
Since you're data is an _image_ it probably isn't 1D.<br>
<br>
You will need to calculate the extents that get you the points<br>
you want.<br>
<div class="im"><br>
> I started to look at the source earlier, and will pick it<br>
> up again tomorrow. In the mean time, any more tips or code<br>
> samples would be appreciated.<br>
><br>
<br>
</div>Look at the doxygen generated documentation :<br>
<br>
<a href="http://www.vtk.org/doc/nightly/html/classvtkXMLImageDataReader.html" target="_blank">http://www.vtk.org/doc/nightly/html/classvtkXMLImageDataReader.html</a><br>
<br>
<br>
<br>
</blockquote></div><br><br clear="all"><div><br></div>-- <br>Grant McAuley<div>Postdoctoral Fellow</div><div>Radiation Research Labs</div><div>Radiation Medicine</div><div>Loma Linda University</div><div>(909) 558-1000 Ext 85173</div>
<div><a href="mailto:gmcauley@llu.edu" target="_blank">gmcauley@llu.edu</a></div>