# MedicalDemo4

VTKExamples/Java/Medical/MedicalDemo4

### Description¶

Volume rendering of the dataset.

Info

Note

This original source code for this example is here.

Other Languages

See (Cxx), (Python)

### Code¶

MedicalDemo4.java

import vtk.vtkNamedColors;
import vtk.vtkNativeLibrary;
import vtk.vtkRenderWindow;
import vtk.vtkRenderWindowInteractor;
import vtk.vtkRenderer;
import vtk.vtkCamera;
import vtk.vtkColorTransferFunction;
import vtk.vtkPiecewiseFunction;
import vtk.vtkFixedPointVolumeRayCastMapper;
import vtk.vtkVolumeProperty;
import vtk.vtkVolume;

public class MedicalDemo4
{
// -----------------------------------------------------------------
// Load VTK library and print which library was not properly loaded
static
{
{
for (vtkNativeLibrary lib : vtkNativeLibrary.values())
{
{
}
}
}
vtkNativeLibrary.DisableOutputWindow(null);
}
// -----------------------------------------------------------------

public static void main(String args[])
{

//parse command line arguments
if (args.length != 1)
{
System.err.println("Usage: java -classpath ... Filename(.mhd) e.g FullHead.mhd");
return;
}
String inputFilename = args[0];

vtkNamedColors colors = new vtkNamedColors();

double Bgcolor[] = new double[4];

colors.GetColor("SteelBlue", Bgcolor);

// Create the renderer, render window and interactor.
vtkRenderer ren = new vtkRenderer();
vtkRenderWindow renWin = new vtkRenderWindow();
vtkRenderWindowInteractor iren = new vtkRenderWindowInteractor();
iren.SetRenderWindow(renWin);

// 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
// uses 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.)

// The volume will be displayed by ray-cast alpha compositing.
// A ray-cast mapper is needed to do the ray-casting.
vtkFixedPointVolumeRayCastMapper volumeMapper = new vtkFixedPointVolumeRayCastMapper();

// The color transfer function maps voxel intensities to colors.
// It is modality-specific, and often anatomy-specific as well.
// The goal is to one color for flesh (between 500 and 1000)
// and another color for bone (1150 and over).
vtkColorTransferFunction volumeColor = new vtkColorTransferFunction();

// The opacity transfer function is used to control the opacity
// of different tissue types.
vtkPiecewiseFunction volumeScalarOpacity = new vtkPiecewiseFunction();

// The gradient opacity function is used to decrease the opacity
// in the "flat" regions of the volume while maintaining the opacity
// at the boundaries between tissue types.  The gradient is measured
// as the amount by which the intensity changes over unit distance.
// For most medical data, the unit distance is 1mm.

// The VolumeProperty attaches the color and opacity functions to the
// volume, and sets other volume properties.  The interpolation should
// be set to linear to do a high-quality rendering.  The ShadeOn option
// turns on directional lighting, which will usually enhance the
// appearance of the volume and make it look more "3D".  However,
// the quality of the shading depends on how accurately the gradient
// of the volume can be calculated, and for noisy data the gradient
// estimation will be very poor.  The impact of the shading can be
// decreased by increasing the Ambient coefficient while decreasing
// the Diffuse and Specular coefficient.  To increase the impact
// of shading, decrease the Ambient and increase the Diffuse and Specular.
vtkVolumeProperty volumeProperty = new vtkVolumeProperty();
volumeProperty.SetColor(volumeColor);
volumeProperty.SetScalarOpacity(volumeScalarOpacity);
volumeProperty.SetInterpolationTypeToLinear();
volumeProperty.SetAmbient(0.4);
volumeProperty.SetDiffuse(0.6);
volumeProperty.SetSpecular(0.2);

// The vtkVolume is a vtkProp3D (like a vtkActor) and controls the position
// and orientation of the volume in world coordinates.
vtkVolume volume = new vtkVolume();
volume.SetMapper(volumeMapper);
volume.SetProperty(volumeProperty);
double c[] = new double[3];
c=volume.GetCenter();

// Set up an initial view of the volume.  The focal point will be the
// center of the volume, and the camera position will be 400mm to the
// patient's left (which is our right).

vtkCamera camera = new vtkCamera();
camera.SetViewUp (0, 0, -1);
camera.SetPosition (c[0], c[1] - 400, c[2]);
camera.SetFocalPoint (c[0], c[1], c[2]);
camera.Azimuth(30.0);
camera.Elevation(30.0);
camera.Dolly(0.75);

// Actors are added to the renderer. An initial camera view is created.
// The Dolly() method moves the camera towards the FocalPoint, thereby enlarging the image.

ren.SetActiveCamera(camera);

// Set a background color for the renderer and set the size of the
// render window (expressed in pixels).
ren.SetBackground(Bgcolor);

// Note that when camera movement occurs (as it does in the Dolly()
// method), the clipping planes often need adjusting. Clipping planes
// consist of two planes: near and far along the view direction. The
// near plane clips out objects in front of the plane; the far plane
// clips out objects behind the plane. This way only what is drawn
// between the planes is actually rendered.
ren.ResetCameraClippingRange ();

renWin.SetSize(300, 300);
renWin.Render();

iren.Initialize();
iren.Start();
}
}