TransformOrderDemo
VTKExamples/Cxx/PolyData/TransformOrderDemo
Description
This example creates an image. In the left viewport, it translates the image, then translates and rotates the image. In the right viewport, it rotates the image, then rotates and translates the image. One can see that the result is clearly not the same!
Code
TransformOrderDemo.cxx
#include <vtkSmartPointer.h>
#include <vtkTransform.h>
#include <vtkAxesActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkImageMandelbrotSource.h>
#include <vtkImageActor.h>
#include <vtkImageMapper3D.h>
#include <vtkImageCast.h>
int main(int, char *[])
{
// Create an image
vtkSmartPointer<vtkImageMandelbrotSource> source =
vtkSmartPointer<vtkImageMandelbrotSource>::New();
source->Update();
vtkSmartPointer<vtkImageCast> castFilter =
vtkSmartPointer<vtkImageCast>::New();
castFilter->SetInputConnection(source->GetOutputPort());
castFilter->SetOutputScalarTypeToUnsignedChar();
castFilter->Update();
// Create an actor
vtkSmartPointer<vtkImageActor> actor1a =
vtkSmartPointer<vtkImageActor>::New();
actor1a->GetMapper()->SetInputConnection(castFilter->GetOutputPort());
vtkSmartPointer<vtkImageActor> actor1b =
vtkSmartPointer<vtkImageActor>::New();
actor1b->GetMapper()->SetInputConnection(castFilter->GetOutputPort());
vtkSmartPointer<vtkImageActor> actor2a =
vtkSmartPointer<vtkImageActor>::New();
actor2a->GetMapper()->SetInputConnection(castFilter->GetOutputPort());
vtkSmartPointer<vtkImageActor> actor2b =
vtkSmartPointer<vtkImageActor>::New();
actor2b->GetMapper()->SetInputConnection(castFilter->GetOutputPort());
// Create the transformation
vtkSmartPointer<vtkTransform> transform1a =
vtkSmartPointer<vtkTransform>::New();
transform1a->PostMultiply();
transform1a->Translate(10.0, 0.0, 0.0);
actor1a->SetUserTransform(transform1a);
vtkSmartPointer<vtkTransform> transform1b =
vtkSmartPointer<vtkTransform>::New();
transform1b->PostMultiply();
transform1b->Translate(10.0, 0.0, 0.0);
transform1b->RotateZ(40.0);
actor1b->SetUserTransform(transform1b);
vtkSmartPointer<vtkTransform> transform2a =
vtkSmartPointer<vtkTransform>::New();
transform2a->PostMultiply();
transform2a->RotateZ(40.0);
actor2a->SetUserTransform(transform2a);
vtkSmartPointer<vtkTransform> transform2b =
vtkSmartPointer<vtkTransform>::New();
transform2b->PostMultiply();
transform2b->RotateZ(40.0);
transform2b->Translate(10.0, 0.0, 0.0);
actor2b->SetUserTransform(transform2b);
// Define viewport ranges
// (xmin, ymin, xmax, ymax)
double leftViewport[4] = {0.0, 0.0, 0.5, 1.0};
double rightViewport[4] = {0.5, 0.0, 1.0, 1.0};
// Cetup render window
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
// Setup both renderers
vtkSmartPointer<vtkRenderer> leftRenderer =
vtkSmartPointer<vtkRenderer>::New();
renderWindow->AddRenderer(leftRenderer);
leftRenderer->SetViewport(leftViewport);
leftRenderer->SetBackground(.6, .5, .4);
vtkSmartPointer<vtkRenderer> rightRenderer =
vtkSmartPointer<vtkRenderer>::New();
renderWindow->AddRenderer(rightRenderer);
rightRenderer->SetViewport(rightViewport);
rightRenderer->SetBackground(.4, .5, .6);
// an interactor
vtkSmartPointer<vtkRenderWindowInteractor> interactor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
interactor->SetRenderWindow(renderWindow);
vtkSmartPointer<vtkAxesActor> axes =
vtkSmartPointer<vtkAxesActor>::New();
axes->AxisLabelsOff();
axes->SetTotalLength(5,5,5);
leftRenderer->AddActor(axes);
leftRenderer->AddActor(actor1a);
leftRenderer->AddActor(actor1b);
rightRenderer->AddActor(axes);
rightRenderer->AddActor(actor2a);
rightRenderer->AddActor(actor2b);
leftRenderer->ResetCamera();
rightRenderer->ResetCamera();
renderWindow->Render();
interactor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(TransformOrderDemo)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(TransformOrderDemo MACOSX_BUNDLE TransformOrderDemo.cxx)
target_link_libraries(TransformOrderDemo ${VTK_LIBRARIES})
Download and Build TransformOrderDemo
Click here to download TransformOrderDemo and its CMakeLists.txt file. Once the tarball TransformOrderDemo.tar has been downloaded and extracted,
cd TransformOrderDemo/build
If VTK is installed:
cmake ..
If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:
cmake -DVTK_DIR:PATH=/home/me/vtk_build ..
Build the project:
make
and run it:
./TransformOrderDemo
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.