Delete highlighted points

virtual void OnKeyPress() {
    vtkRenderWindowInteractor *rwi = this->Interactor;
    const char* ch = rwi->GetKeySym ();
     if (strcmp (ch, "Delete") == 0) {
        vtkPlanes* frustum = static_cast<vtkAreaPicker*>(this->GetInteractor()->GetPicker())->GetFrustum();

        vtkSmartPointer<vtkExtractGeometry> extractGeometry =
            vtkSmartPointer<vtkExtractGeometry>::New();
        extractGeometry->SetImplicitFunction(frustum);
        extractGeometry->SetInputData(this->Points);
        extractGeometry->SetExtractInside(0);          //We want all points outside the geometry
        extractGeometry->Update();

        vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
            vtkSmartPointer<vtkVertexGlyphFilter>::New();
        glyphFilter->SetInputConnection(extractGeometry->GetOutputPort());
        glyphFilter->Update();

        vtkPolyData* selected = glyphFilter->GetOutput ();

        vtkIdTypeArray* ids = vtkIdTypeArray::SafeDownCast(selected->GetPointData()->GetArray("OriginalIds"));
        vtkSmartPointer<vtkPoints> newPoints = vtkSmartPointer<vtkPoints>::New();
        for(vtkIdType i = 0; i < ids->GetNumberOfTuples(); i++) {
            newPoints->InsertPoint(ids->GetValue(i), this->Points->GetPoint (ids->GetValue(i)));
        }

        this->Points->SetPoints (newPoints);
        this->GetInteractor()->GetRenderWindow()->Render();
     }
}