[vtkusers]help: Volume Rendering problems

[lpf]

Yes, you are right. I have resolved it by adopting your suggestion.

Thank you very much!

Pengfei Liu
----- Original Message ----- 
From: "Marc Cotran" <marc at cotran.ca>
To: "lpf" <lpf at vico-lab.com>
Sent: Monday, November 21, 2005 11:03 PM
Subject: Re: [vtkusers]help: Volume Rendering problems


> Hi,
> 
> I don't believe the mapper supports float data. Try using vtkImageCast
> to cast the data to unsigned short or unsigned char.
> 
> HTH
> 
> Marc
> 
> lpf wrote:
>> Hi, VTK users
>>    Now I am rendering a volume Data, it is raw single 3D data, at first 
>> I render it slice by slice, it is no problem,
>> so I think file reading is no problem , but when I render it as volume, 
>> Nothing display, who can tell me what's wrong
>>    My VTK is Version 4.0
>>    Here is the code
>> ------------------------------------------------------
>> #include "vtkImageReader.h"
>> #include "vtkRenderer.h"
>> #include "vtkRenderWindow.h"
>> #include "vtkRenderWindowInteractor.h"
>> #include "vtkPiecewiseFunction.h"
>> #include "vtkColorTransferFunction.h"
>> #include "vtkVolumeProperty.h"
>> #include "vtkVolumeRayCastCompositeFunction.h"
>> #include "vtkVolumeRayCastMapper.h"
>> #include "vtkVolume.h"
>> int main()
>> {
>> vtkImageReader* reader = vtkImageReader::New();
>>  reader->SetFileName("D:\\volume.im"); //single 3D raw data
>>  reader->SetDataScalarTypeToFloat();
>>  reader->SetDataByteOrderToBigEndian();
>>  reader->SetFileDimensionality(3);
>>  reader->SetDataExtent(0,255,0,127,0,127);
>>  reader->SetDataSpacing(0.39,0.78,0.78);
>>  reader->SetHeaderSize(0);
>>  reader->Update();
>> 
>> vtkPiecewiseFunction *opacityFun = vtkPiecewiseFunction::New();
>>  opacityFun->AddPoint(0,  0.0);
>>  opacityFun->AddPoint(10, 0.0);
>>  opacityFun->AddPoint(500, 0.1);
>>  opacityFun->AddPoint(5000, 0.4);
>> 
>> vtkColorTransferFunction *colorFun = vtkColorTransferFunction::New();
>>  colorFun->AddRGBPoint(0, 0.3, 0.3, 1.0);
>>  colorFun->AddRGBPoint(5000,1.0, 0.0, 0.0);
>> 
>> vtkVolumeProperty *volProperty = vtkVolumeProperty::New();
>>  volProperty->SetScalarOpacity(opacityFun);
>>  volProperty->SetColor(colorFun);
>> 
>> vtkVolumeRayCastCompositeFunction *compositeFun = 
>> vtkVolumeRayCastCompositeFunction::New();
>> 
>> vtkVolumeRayCastMapper *volumeMapper = vtkVolumeRayCastMapper::New();
>>  volumeMapper->SetVolumeRayCastFunction(compositeFun);
>>  volumeMapper->SetInput(reader->GetOutput());
>> 
>> vtkVolume* volProp = vtkVolume::New();
>>  volProp->SetMapper(volumeMapper);
>>  volProp->SetProperty(volProperty);
>> 
>> vtkRenderer *render = vtkRenderer::New();
>>  render->AddVolume(volProp);
>>  render->SetBackground(1.0,1.0,1.0);
>> vtkRenderWindow *renWin = vtkRenderWindow::New();
>> vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
>>  renWin->AddRenderer(render);
>>  renWin->SetSize(500,500);
>>  renWin->SetInteractor(iren);
>> 
>> renWin->Render();
>> iren->Start();
>> }
>> ------------------------------------------------------
>> 
>> 
>> 
>> Best regards
>> PengFei Liu
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