[vtkusers] vtkSampleFunction and vtkImageWriter

[Mathieu Malaterre]

David,

	Use vtkImageCast:

http://www.vtk.org/doc/nightly/html/classvtkImageCast.html

Mathieu
Ps: Also please search the ML archive before asking a question, thanks.

David Stocks wrote:
> Hello,
> 
> I'm trying to generate an image stack from an implicit function.  In 
> doing this, I'm trying to feed the output of vtkSampleFunction into 
> vtkTIFFWriter as shown below.  When I run this, I get the output:
> 
> dstocks at pattiesmuir[~/CIRCE/vtk/Cxx]% ./coneWriter
> we want: 3
> we got:  3
> ERROR: In /tmp/dstocks/VTK/IO/vtkTIFFWriter.cxx, line 463
> vtkTIFFWriter (0x8056810): TIFFWriter only accepts unsigned char scalars!
> 
> ERROR: In /tmp/dstocks/VTK/IO/vtkTIFFWriter.cxx, line 463
> vtkTIFFWriter (0x8056810): TIFFWriter only accepts unsigned char scalars!
> 
> [ ... ]
> 
> As far as I can see I'm setting the sample function output to the right 
> type, but yet something is clearly amiss.  Any suggestions?
> 
> Thanks in advance,
> David.
> 
> #include <iostream>
> 
> #include "vtkCone.h"
> #include "vtkSampleFunction.h"
> #include "vtkTIFFWriter.h"
> 
> #define SAMPLE_RANGE_X_MIN -1
> #define SAMPLE_RANGE_X_MAX 3
> #define SAMPLE_RANGE_Y_MIN -1.25
> #define SAMPLE_RANGE_Y_MAX 1.25
> #define SAMPLE_RANGE_Z_MIN -1.25
> #define SAMPLE_RANGE_Z_MAX 1.25
> 
> int main(int argc, char *argv[]) {
> 
>   vtkCone *cone = vtkCone::New();
>   cone->SetAngle(30);
> 
>   vtkSampleFunction *theConeSample = vtkSampleFunction::New();
>   theConeSample->SetOutputScalarTypeToUnsignedChar();
>   theConeSample->SetImplicitFunction(cone);
>   theConeSample->SetModelBounds(SAMPLE_RANGE_X_MIN,
>                 SAMPLE_RANGE_X_MAX,
>                 SAMPLE_RANGE_Y_MIN,
>                 SAMPLE_RANGE_Y_MAX,
>                 SAMPLE_RANGE_Z_MIN,
>                 SAMPLE_RANGE_Z_MAX);
>   theConeSample->SetSampleDimensions(50, 50, 50);
>   theConeSample->ComputeNormalsOff();
> 
>   cout << "we want: " << VTK_UNSIGNED_CHAR << endl;
>   cout << "we got:  " << theConeSample->GetOutputScalarType() << endl;
> 
>   vtkTIFFWriter *writer = vtkTIFFWriter::New();
>   writer->SetInput(theConeSample->GetOutput());
>   writer->SetFilePrefix("foo");
>   writer->Write();
> 
>   return(0);
> }
>