[vtkusers] imagedata appearing upside down (sometimes..?)

[Howard Katz]

Hi,

I called GetSpacing and it returns (1,1,1) just as I had specified..
And I know the input values are correct i.e they're not negative or anything 
because I also outputted this..
And I noticed that whenever I don't add a camera to my renderer, nothing 
happens when I change the spacing, is this normal?
Okay below is some C++ code,
So again its werid because the whole thing appears upside down only for some 
cases and not others..?
Anyways here it is:

VelocityVsTimeSampleFloatArray->SetNumberOfComponents(1);
VelocityVsTimeSampleFloatArray->SetNumberOfTuples(TotalCycles*NumVelocityBins*TotalTimePoints 
);
VelocityVsTimeSampleImageData->SetOrigin(-30, -85, 0);
	VelocityVsTimeSampleImageData->GetPointData()->SetScalars(VelocityVsTimeSampleFloatArray);
VelocityVsTimeSampleImageData->SetDimensions(TotalCycles*TotalTimePoints,NumVelocityBins, 
1);
VelocityVsTimeSampleImageData->SetScalarType(VTK_FLOAT);
VelocityVsTimeSampleImageData->SetSpacing(1, 1, 1);

ImageCast->SetInput( VelocityVsTimeSampleImageData);
ImageCast->SetOutputScalarTypeToUnsignedChar();

ImageMapToColors->SetInput(ImageCast->GetOutput());
ImageMapToColors->SetLookupTable(SpectLUT);

SpectActor->SetInput(ImageMapToColors->GetOutput());
SpectActor->SetDisplayExtent( 0, TotalCycles*TotalTimePoints-1, 0, 
NumVelocityBins-1, 0, 0 );

Cam->SetPosition(0, 0, 325);
Cam->SetFocalPoint(0,0,0);

Ren1->SetBackground(0.3, 0.3, 0.3);
Ren1->SetActiveCamera(Cam);
Ren1->AddActor( SpectActor );

RenWin->AddRenderer( Ren1 );
RenWin->SetSize( 500, 500 );
RenWin->SetInteractor(Iren);
Iren->SetStillUpdateRate(1000);
Iren->SetDesiredUpdateRate(1000);
Iren->Initialize();
Iren->Render();




>From: Mathieu Malaterre <mathieu.malaterre at kitware.com>
>To: Howard Katz <lost_bits1110 at hotmail.com>
>CC: vtkusers at vtk.org
>Subject: Re: [vtkusers] imagedata appearing upside down (sometimes..?)
>Date: Mon, 22 Mar 2004 17:34:30 -0500
>
>Howard,
>
>	What does :
>
>//Call Update() before
>print imagedata.GetSpacing()
>
>return ?
>Could you reproduce the bad behavior using a tests from VTK ? Or could you 
>send us a python/c++/tcl code that shows this problem.
>
>Thanks
>Mathieu
>
>Howard Katz wrote:
>>Hi..
>>What do you mean my spacing 'can' be negative...?
>>:S
>>Thanks again..!
>>
>>
>>
>>>From: Mathieu Malaterre <mathieu.malaterre at kitware.com>
>>>To: Howard Katz <lost_bits1110 at hotmail.com>
>>>CC: vtkusers at vtk.org
>>>Subject: Re: [vtkusers] imagedata appearing upside down (sometimes..?)
>>>Date: Mon, 22 Mar 2004 13:13:18 -0500
>>>
>>>Howard Katz wrote:
>>>
>>>>Hi,
>>>>so has anyone run into the problem where their vtkImageData looks upside 
>>>>down only sometiems depending on the input values..?  i.e. I know I am 
>>>>inputting values 10, 20, 15 (for example) but these appear at rows -10, 
>>>>-20, -15  (..and this will happen for the entire image data)
>>>>
>>>>Can anyoen guess what my problem might be?
>>>
>>>
>>>You spacing can be negative, this happens typically in medical image data 
>>>such a MINC or DICOM
>>>
>>>HTH
>>>Mathieu
>>>
>>>
>>
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>
>
>
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