[vtkusers] Re: What Is Wrong With My VTK Pipeline ?

[Sylvain Jaume]

Hi Mark,

(Please keep your postings to vtkusers mailing list.)

vtkImageMandelbrotSource and vtkVolume16Reader are both sources, they 
don't accept an input. They both produce a vtkImageData, so either use 
one or the other for testing your application.

You can convert a vtkImageData to a vtkUnstructuredGrid using 
vtkThreshold. For volume rendering a vtkUnstructuredGrid, have a look at 
the vtkUnstructuredGridVolumeRayCastMapper. You'll find an example in 
VTK/Examples/VolumeRendering/Tcl/IntermixedUnstructuredGrid.tcl

Sincerely,
Sylvain

JohnMark wrote:
> Hi , Sylvain ,
>     thank you for your help within these days . and this is one problem 
> that my friend ask me , but I
> still don't know why it is , even though I have read the vtk user guide 
> and so on :
>     I have been testing some examples of cells during these days . and I 
> find an interesting class :
> vtkImageMandelbrotSource , because its output can be used by volume 
> rendering , although the volume
> rendering is unstructured grid volume rendering .
>     and I find it has an input method : SetInputConnection(vtkDataObject 
> *) , so I think it may be OK
> if I take the output of class vtkVolume16Reader as its input , but , 
> luckily , I get an error :
> Attempt to connect input port index 0 for an algorithm with 0 input 
> ports . but in other examples of
> volume rendering , there is not any error like this , and all of them 
> work well . so I don't think
> there is 0 input ports .
>     the codes is just as follows :
>  
> vtkVolume16Reader *reader = vtkVolume16Reader::New();//**** the v16 
> codes is no problem , I have test it many times .
>   reader->SetDataDimensions(64,64);
>   reader->SetImageRange(1,93);
>   reader->SetDataByteOrderToLittleEndian();
>   reader->SetFilePrefix("../headsq/quarter");
>   reader->SetDataSpacing(3.2, 3.2, 1.5);
> vtkImageMandelbrotSource *input = vtkImageMandelbrotSource::New();
>   input->SetInputConnection(reader->GetOutputPort());
>  
> so there are the problems :
>     1、of course , vtkImageMandelbrotSource can create images by itself 
> , is it real that
> vtkImageMandelbrotSource can not take other images as input ports ? 
>     2、if it is so , all the unstructured grid volume rendering methods 
> can not take random images
> as their input ports ? if it is not , what should I do before I send 
> the images (like .dcm images) to
> vtkImageMandelbrotSource  ?  
>     and I have tried vtkUnstructuredGridAlgorithm , it can transform the 
> images to unstructured grid ,
> just as the unstructured grid volume rendering requires , but it doesn't 
> work .
>     or in other words , these methods , like 
> vtkUnstructuredGridVolumeZSweepMapper , can not be used
> by the medical  visualization system , so which field can they be used ?
>  
>     thank you with great regards !
>    
>     Mark 
>  
> 
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