[vtkusers] vtkImageSlice and vtkImageReslice Mapper

[David Gobbi]

Then what happens if you comment out the im.SliceAtFocalPointOn()
line in the code?  Then the camera will control the slice orientation,
but not the slice, which would instead be controlled by calling
im.GetSlicePlane()->SetOrigin(x,y,z) where (x,y,z) is a point on
the slice that you want to display.

 - David

On Fri, Nov 9, 2012 at 2:53 PM, Sahithya Wintrich <s.prakash at csuohio.edu> wrote:
> I want to select points and add a connecting line through the points on the
> axial slice. Adding an mouse interaction to the modified code from
> VTK/ImageProcessing/Python/ImageInteractorReslice.py causes the axial slice
> not be "static" anymore. Meaning if I hold down the left mouse button and
> drag my mouse around the mouse pad, I am able to visualize the remaining
> volume. I would like to prevent this from happening. Is there are workaround
> to this? (my code below)
>
> class Interaction: public vtkInteractorStyleTrackballCamera
> {
>   public:
>     static Interaction* New();
>     vtkTypeMacro(Interaction, vtkInteractorStyleTrackballCamera);
>
>     void Initiliaze();
>
>     virtual void OnLeftButtonDown()
>     {
>         cout << "Picking pixel: " << this->Interactor->GetEventPosition()[0]
> << " " << this->Interactor->GetEventPosition()[1] << std::endl;
>
> this->Interactor->GetPicker()->Pick(this->Interactor->GetEventPosition()[0],
>                             this->Interactor->GetEventPosition()[1],
>                             0,  // always zero.
>
> this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer());
>         double picked[3];
>         this->Interactor->GetPicker()->GetPickPosition(picked);
>         cout << "Picked value: " << picked[0] << " " << picked[1] << " " <<
> picked[2] << std::endl;
>
>         AddSelectedPoint(picked);
>
>         // code to display the picked values and  locations
>         vtkSmartPointer<vtkRegularPolygonSource> circle =
> vtkSmartPointer<vtkRegularPolygonSource>::New();
>         circle->SetNumberOfSides(50);
>         circle->SetRadius(1);
>         circle->SetCenter(picked[0], picked[1], picked[2]);
>         circle->Update();
>
>         vtkSmartPointer<vtkPolyDataMapper> mapper =
> vtkSmartPointer<vtkPolyDataMapper>::New();
>         mapper->SetInputConnection(circle->GetOutputPort());
>         mapper->Modified();
>
>         vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
>         vtkSmartPointer<vtkProperty> circleProperty =
> vtkSmartPointer<vtkProperty>::New();
>         circleProperty->SetColor(1, 1, 0);
>         //circleProperty->SetOpacity(0.0);
>         circleProperty->EdgeVisibilityOn();
>         circleProperty->SetEdgeColor(1, 0, 0);
>         actor->SetMapper(mapper);
>         actor->SetProperty(circleProperty);
>
> this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer()->AddActor(actor);
>
> this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer()->Render();
>
>         // Forward events
>         vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
>      };
>
>
>   private:
>       void AddSelectedPoint(double point[]);
>
>
>
> };
>
> main.cpp
>
>   vtkSmartPointer<Interaction> mouseStyle =
> vtkSmartPointer<Interaction>::New();
>   mouseStyle->Initiliaze();
>   mouseStyle->SetDefaultRenderer(renderer);
>
>   iren->SetInteractorStyle( mouseStyle );
>
> Thanks for any help!
>
> Sahithya
>
>
>
> On Fri, Nov 2, 2012 at 6:03 PM, David Gobbi <david.gobbi at gmail.com> wrote:
>>
>> Hi Sahithya,
>>
>> The following example comes with the VTK source code:
>>
>> VTK/ImageProcessing/Python/ImageInteractorReslice.py
>>
>> Note that you cannot use SetSlicePlane() together with
>> SliceFacesCameraOn() and SliceAtFocalPointOn(),
>> because when the latter two methods are used, the slice
>> plane will be automatically set from the camera parameters
>> and any value you set with SetSlicePlane() will be ignored.
>>
>>  - David
>>
>>
>> On Fri, Nov 2, 2012 at 3:39 PM, Sahithya Wintrich <s.prakash at csuohio.edu>
>> wrote:
>> > Hello,
>> >
>> > I am new to VTK and visualization in general. I am trying to extract a
>> > 2D
>> > slice from a 3D volume. The classes I use are as follows:
>> >
>> > vtkImageReader - reads the stack of 2D CT images
>> > vtkVolumeTextureMapper2D - Maps the volume
>> >
>> > in order to get a slice defined by a vtkPlane with origin and normal
>> > corresponding to the slice of interest, I use:
>> >
>> >     mapper = vtkImageResliceMapper::New();
>> >     mapper->SetInputConnection(
>> > reader->GetOuputPort());
>> >     mapper->SetSlicePlane(plane);
>> >
>> >     slice = vtkImageSlice::New();
>> >     slice->SetMapper(mapper);
>> >
>> >     renderer->AddViewProp(slice);
>> >
>> > I understand that the vtkImageSlice is a 3D prop and I tried using
>> > suggestions to change the position and focal point of the camera.
>> > However,
>> > this is still displayed in a 3D space. I need to display this as a 2D
>> > slice
>> > with a correct view (for oblique slices as well) and prevent the user
>> > from
>> > rotating the slice.
>> >
>> > Any help would be greatly appreciated!
>> >
>> > Sahithya
>
>