[vtkusers] Volume rendering

[xiong fei]

Thank you for your advice. But when I try it in my
program, that error still exist.
"ERROR: In
d:\nightly\vtk\graphics\vtkVolumeRayCastMapper.cxx,
line 912
vtkVolumeRayCastMapper (0x007EADB0): The scalar data
type: 4 is not supported when volume rendering. Please
convert the  data to unsigned char or unsigned short."

I have put my sourse code below, can you take a look?
Your help is greatly appreciated.

//some codes from example "volProt.cxx"

void main( int argc, char *argv[] )
{
    vtkDataSet *dataSet;
    // read data
    dataSet = ReadFinancialData();

    if (! dataSet) exit(0);
  
  // Create the renderer, render window, and
interactor
  vtkRenderer *ren1 = vtkRenderer::New();
  vtkRenderWindow *renWin = vtkRenderWindow::New();
    renWin->AddRenderer(ren1);
  vtkRenderWindowInteractor *iren =
vtkRenderWindowInteractor::New();
    iren->SetRenderWindow(renWin);
  
    vtkGaussianSplatter *popSplatter =
vtkGaussianSplatter::New();
    popSplatter->SetInput(dataSet);
    popSplatter->SetSampleDimensions(50,50,50);
    popSplatter->SetRadius(0.05);
    popSplatter->ScalarWarpingOff();
    
    vtkImageCast *cast = vtkImageCast::New();
    cast->SetInput(popSplatter->GetOutput());
    cast->SetOutputScalarTypeToShort();

  // Read data from original dataset and transfer it
to structuredpoints
  
  // Create a transfer function mapping scalar value
to opacity
  vtkPiecewiseFunction *oTFun =
vtkPiecewiseFunction::New();
    oTFun->AddSegment(80, 0.0, 255, 1.0);

  // Create a transfer function mapping scalar value
to color (grey)
  vtkPiecewiseFunction *cTFun =
vtkPiecewiseFunction::New();
    cTFun->AddSegment(0, 1.0, 255, 1.0);

  // Create a property for the volume and set the
transfer functions.
  // Turn shading on and use trilinear interpolation
  vtkVolumeProperty *volumeProperty =
vtkVolumeProperty::New();
    volumeProperty->SetColor(cTFun);
    volumeProperty->SetScalarOpacity(oTFun);
    volumeProperty->SetInterpolationTypeToLinear();
    volumeProperty->ShadeOn();

  // Create a ray function - this is a compositing ray
function
  vtkVolumeRayCastCompositeFunction *compositeFunction
= 
    vtkVolumeRayCastCompositeFunction::New();

  // Create the volume mapper and set the ray function
and scalar input
  vtkVolumeRayCastMapper *volumeMapper =
vtkVolumeRayCastMapper::New();
   //****
    volumeMapper->SetInput(cast->GetOutput());
   
volumeMapper->SetVolumeRayCastFunction(compositeFunction);

  // Create the volume and set the mapper and property
  vtkVolume *volume = vtkVolume::New();
    volume->SetMapper(volumeMapper);
    volume->SetProperty(volumeProperty);

  // Add this volume to the renderer and get a closer
look
  ren1->AddVolume(volume);
  ren1->GetActiveCamera()->Azimuth(20.0);
  ren1->GetActiveCamera()->Dolly(1.60);
  ren1->ResetCameraClippingRange();
  
  renWin->SetSize(300,300);

  renWin->Render();

  SAVEIMAGE( renWin );

  // Interact with the data at 3 frames per second
  iren->SetDesiredUpdateRate(3.0);
  iren->SetStillUpdateRate(0.001);
  iren->Start();

  // Clean up
  ren1->Delete();
  renWin->Delete();
  iren->Delete();
  popSplatter->Delete();
  oTFun->Delete();
  cTFun->Delete();
  volumeProperty->Delete();
  compositeFunction->Delete();
  volumeMapper->Delete();
  volume->Delete();
}


--- bo wang <bowang at iastate.edu> wrote: > 
> -----Original Message-----
> From: xiong fei <xfpku at yahoo.com.sg>
> To: vtkusers at public.kitware.com
> <vtkusers at public.kitware.com>
> Date: Wednesday, February 14, 2001 9:53 PM
> Subject: Re: [vtkusers] Volume rendering
> 
> 
> >Hi, all
> >
> >   Sorry to post this message again, but I am
> really
> >stuck now. As what was said before, I want to
> >visualize some financial data using volume
> rendering.
> >But the question is how to do it? 
> >   I have tried vtkGaussianSplatter or
> >vtkShepardMethod to transfer the raw data to be
> >structured points, and it really did. However, when
> I
> >try to run the program, a error is reported :
> >"vtkVolumeRayCastMapper (0x10031048): The scalar
> data
> >type: 10 is not supported when volume rendering.
> >Please convert the  data to unsigned char or
> unsigned
> >short." So what shall I do next? can someone help
> me?
> >Thanks.
>  
> use vtkImageCast to convert the data type.
> 
> 
> 
> 
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