// The following reader is used to read a series of 2D slices (images)
// that compose the volume. The slice dimensions are set, and the
// pixel spacing. The data Endianness must also be specified. The reader
// usese the FilePrefix in combination with the slice number to construct
// filenames using the format FilePrefix.%d. (In this case the FilePrefix
// is the root name of the file: quarter.)
vtkVolume16Reader *v16 = vtkVolume16Reader::New();
v16->SetDataDimensions (64,64);
v16->SetImageRange (1,93);
v16->SetDataByteOrderToLittleEndian();
v16->SetFilePrefix (argv[1]);
v16->SetDataSpacing (3.0, 3.0, 1.5);
// An isosurface, or contour value of 500 is known to correspond to the
// skin of the patient. Once generated, a vtkPolyDataNormals filter is
// is used to create normals for smooth surface shading during rendering.
vtkContourFilter *skinExtractor = vtkContourFilter::New();
skinExtractor->SetInput((vtkDataSet *) v16->GetOutput());
skinExtractor->SetValue(0, 500);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
待提取的等值面灰度值