Hi ,
I am new to vtk ,I want to display a 3d volume of .mhd file. I reused the following code which I got off the net ,made some changes to support vtk6.` /*=========================================================================
Program: Visualization Toolkit
Module: ImageSlicing.cxx
Copyright © Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
//
// This example shows how to load a 3D image into VTK and then reformat
// that image into a different orientation for viewing. It uses
// vtkImageReslice for reformatting the image, and uses vtkImageActor
// and vtkInteractorStyleImage to display the image. This InteractorStyle
// forces the camera to stay perpendicular to the XY plane.
//
// Thanks to David Gobbi of Atamai Inc. for contributing this example.
//
#include <vtkMetaImageReader.h>
#include <vtkSmartPointer.h>
#include “vtkMatrix4x4.h”
#include “vtkImageReslice.h”
#include “vtkLookupTable.h”
#include “vtkImageMapToColors.h”
#include “vtkImageActor.h”
#include “vtkRenderer.h”
#include “vtkRenderWindow.h”
#include “vtkRenderWindowInteractor.h”
#include “vtkInteractorStyleImage.h”
#include “vtkCommand.h”
#include “vtkImageData.h”
// The mouse motion callback, to turn “Slicing” on and off
class vtkImageInteractionCallback : public vtkCommand
{
public:
static vtkImageInteractionCallback *New() {
return new vtkImageInteractionCallback; };
vtkImageInteractionCallback() {
this->Slicing = 0;
this->ImageReslice = 0;
this->Interactor = 0; };
void SetImageReslice(vtkImageReslice *reslice) {
this->ImageReslice = reslice; };
vtkImageReslice *GetImageReslice() {
return this->ImageReslice; };
void SetInteractor(vtkRenderWindowInteractor *interactor) {
this->Interactor = interactor; };
vtkRenderWindowInteractor *GetInteractor() {
return this->Interactor; };
virtual void Execute(vtkObject *, unsigned long event, void *)
{
vtkRenderWindowInteractor *interactor = this->GetInteractor();
int lastPos[2];
interactor->GetLastEventPosition(lastPos);
int currPos[2];
interactor->GetEventPosition(currPos);
if (event == vtkCommand::LeftButtonPressEvent)
{
std::cout << "left button press event" << "\n";
this->Slicing = 1;
}
else if (event == vtkCommand::LeftButtonReleaseEvent)
{
this->Slicing = 0;
}
else if (event == vtkCommand::MouseMoveEvent)
{
if (this->Slicing)
{
vtkImageReslice *reslice = this->ImageReslice;
// Increment slice position by deltaY of mouse
int deltaY = lastPos[1] - currPos[1];
std::cout << deltaY << "\n";
// reslice->GetOutput()
double sliceSpacing = reslice->GetOutput()->GetSpacing()[2];
vtkMatrix4x4 *matrix = reslice->GetResliceAxes();
// move the center point that we are slicing through
double point[4];
double center[4];
point[0] = 0.0;
point[1] = 0.0;
point[2] = sliceSpacing * deltaY;
point[3] = 1.0;
matrix->MultiplyPoint(point, center);
matrix->SetElement(0, 3, center[0]);
matrix->SetElement(1, 3, center[1]);
matrix->SetElement(2, 3, center[2]);
interactor->Render();
}
else
{
vtkInteractorStyle *style = vtkInteractorStyle::SafeDownCast(
interactor->GetInteractorStyle());
if (style)
{
style->OnMouseMove();
}
}
}
};
private:
// Actions (slicing only, for now)
int Slicing;
// Pointer to vtkImageReslice
vtkImageReslice *ImageReslice;
// Pointer to the interactor
vtkRenderWindowInteractor *Interactor;
};
// The program entry point
int main (int argc, char **argv)
{
if (argc < 2)
{
cout << “Usage: " << argv[0] << " DATADIR/headsq/quarter” << endl;
return 1;
}
// Start by loading some data.
std::string inputFilename = argv[1];
vtkSmartPointer reader =
vtkSmartPointer::New();
reader->SetFileName(inputFilename.c_str());
// reader->SetFilePrefix(argv[1]);
reader->SetDataExtent(0, 256, 0, 256, 1, 94);
reader->SetDataSpacing(0.9375, 0.9375, 1.5);
reader->SetDataOrigin(0.0, 0.0, 0.0);
//reader->SetDataScalarTypeToUnsignedShort();
reader->UpdateWholeExtent();
reader->UpdateInformation();
// Calculate the center of the volume
// reader->GetOutput()->UpdateInformation();
int extent[6];
double spacing[3];
double origin[3];
reader->GetOutput()->GetExtent(extent);
reader->GetOutput()->GetSpacing(spacing);
reader->GetOutput()->GetOrigin(origin);
double center[3];
center[0] = origin[0] + spacing[0] * 0.5 * (extent[0] + extent[1]);
center[1] = origin[1] + spacing[1] * 0.5 * (extent[2] + extent[3]);
center[2] = origin[2] + spacing[2] * 0.5 * (extent[4] + extent[5]);
std::cout << “Center:”;
std::cout << center[0] << “,” << center[1] << “,” << center[2] << “\n”;
// Matrices for axial, coronal, sagittal, oblique view orientations
static double axialElements[16] = {
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1 };
static double coronalElements[16] = {
1, 0, 0, 0,
0, 0, 1, 0,
0,-1, 0, 0,
0, 0, 0, 1 };
static double sagittalElements[16] = {
0, 0,-1, 0,
1, 0, 0, 0,
0,-1, 0, 0,
0, 0, 0, 1 };
static double obliqueElements[16] = {
1, 0, 0, 0,
0, 0.866025, -0.5, 0,
0, 0.5, 0.866025, 0,
0, 0, 0, 1 };
// Set the slice orientation
vtkMatrix4x4 *resliceAxes = vtkMatrix4x4::New();
resliceAxes->DeepCopy(sagittalElements);
// Set the point through which to slice
resliceAxes->SetElement(0, 3, center[0]);
resliceAxes->SetElement(1, 3, center[1]);
resliceAxes->SetElement(2, 3, center[2]);
// Extract a slice in the desired orientation
vtkImageReslice *reslice = vtkImageReslice::New();
reslice->SetInputConnection(reader->GetOutputPort());
reslice->SetOutputDimensionality(2);
reslice->SetResliceAxes(resliceAxes);
reslice->SetInterpolationModeToLinear();
// Create a greyscale lookup table
vtkLookupTable *table = vtkLookupTable::New();
table->SetRange(0, 2000); // image intensity range
table->SetValueRange(0.0, 1.0); // from black to white
table->SetSaturationRange(0.0, 0.0); // no color saturation
table->SetRampToLinear();
table->Build();
// Map the image through the lookup table
vtkImageMapToColors *color = vtkImageMapToColors::New();
color->SetLookupTable(table);
color->SetInputConnection(reslice->GetOutputPort());
// Display the image
vtkImageActor *actor = vtkImageActor::New();
actor->SetInputData(color->GetOutput());
vtkRenderer *renderer = vtkRenderer::New();
renderer->AddActor(actor);
vtkRenderWindow *window = vtkRenderWindow::New();
window->AddRenderer(renderer);
// Set up the interaction
vtkInteractorStyleImage *imageStyle = vtkInteractorStyleImage::New();
vtkRenderWindowInteractor *interactor = vtkRenderWindowInteractor::New();
interactor->SetInteractorStyle(imageStyle);
window->SetInteractor(interactor);
window->Render();
vtkImageInteractionCallback *callback = vtkImageInteractionCallback::New();
callback->SetImageReslice(reslice);
callback->SetInteractor(interactor);
imageStyle->AddObserver(vtkCommand::MouseMoveEvent, callback);
imageStyle->AddObserver(vtkCommand::LeftButtonPressEvent, callback);
imageStyle->AddObserver(vtkCommand::LeftButtonReleaseEvent, callback);
// Start interaction
// The Start() method doesn’t return until the window is closed by the user
interactor->Start();
std::cout << “interactor done” << “\n”;
// Clean up
callback->Delete();
interactor->Delete();
imageStyle->Delete();
window->Delete();
renderer->Delete();
actor->Delete();
reslice->Delete();
resliceAxes->Delete();
color->Delete();
table->Delete();
reader->Delete();
}
This displays an empty window.I am not able to find out the problem. Could someone help me with this please
-swetha
`