[vtkusers] vtkRayCaseVolume mapper in VTK 4.0

[Bill Lorensen]

Alex,

There is really not a good justification for the limitation. I believe the concern is that the transfer functions cannot handle negative independent variables, but this, in my opinion, is an implementation flaw.

Although I'm not a volume rendering guy, one of these days, I'll remove this limitation...

Bill


At 09:49 PM 12/20/02 +0300, Alex Romadinoff wrote:
>But what's the reason for such limitations?
>
>Alex
>
>-----Original Message-----
>From: Amy Henderson [mailto:amy.henderson at kitware.com] 
>Sent: Friday, December 20, 2002 9:44 PM
>To: Alex Romadinoff; vtkusers at public.kitware.com
>Subject: Re: [vtkusers] vtkRayCaseVolume mapper in VTK 4.0
>
>At 09:42 PM 12/20/2002 +0300, Alex Romadinoff wrote:
>>Dear all,
>>
>>I try to render volume data with the following code
>>
>>// :skipped:
>>short* data=new short [1000000];
>>
>>  for (int i=0; i<1000000; i++){
>>      data[i]=120+200*sin(i)*((i+1)%20);
>>  }
>>
>>  vtkImageImport *img=vtkImageImport::New();
>>
>>  img->SetImportVoidPointer (data);
>>  img->SetDataScalarTypeToShort ();
>>  img->SetWholeExtent (0, 100, 0, 100, 0, 100);
>>  img->SetDataExtentToWholeExtent ();
>>// ..skipped..
>>vtkVolumeRayCastMapper* volumeMapper=vtkVolumeRayCastMapper::New();
>>volumeMapper->SetVolumeRayCastFunction (compositeFunction);
>>volumeMapper->SetInput (img->GetOutput());
>>// ..skipped
>>
>>When I use short or double type for data array and do
>>SetDataScalarTypeTo{Short|Double} the resultant rendered image is
>empty.
>>
>>When I use unsigned char for data transition, volume is visualized
>well.
>>
>>What's up ?
>>Is vtkVolumeRayCastMapper works only for unsigned char data ?
>
>It will handle unsigned char or unsigned short data.
>- Amy
>
>>With best wishes,
>>Alex
>>
>>
>>
>>
>>
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>
>
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