# error with a same vtkactor add in different vtkrender
**URL:** https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045
**Category:** Support
**Created:** [June 23, 2021, 4:46am UTC](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045 "2021-06-23T04:46:21Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Hurmean](https://discourse.vtk.org/u/Hurmean)
#### Post date: [June 23, 2021, 4:46am UTC](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045/1 "2021-06-23T04:46:21Z")
when a vtkactor add in differert vtkrender with different vtkrenderwindow, this doesn’t work.
---
### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [June 23, 2021, 5:15am UTC](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045/2 "2021-06-23T05:15:27Z")
You can reuse the data object (such as vtkImageData, vtkPolyData), but you cannot reuse mappers or actors in different renderers.
---
### Author:  [@Hurmean](https://discourse.vtk.org/u/Hurmean)
#### Post date: [June 23, 2021, 5:37am UTC](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045/3 "2021-06-23T05:37:03Z")
but this code can work
namespace {
std::vector\ GetSources();
```
// Define interaction style
class KeyPressInteractorStyle : public vtkInteractorStyleTrackballCamera
{
public:
static KeyPressInteractorStyle* New();
vtkTypeMacro(KeyPressInteractorStyle, vtkInteractorStyleTrackballCamera);
virtual void OnKeyPress()
{
// Get the keypress
vtkRenderWindowInteractor* rwi = this->Interactor;
std::string key = rwi->GetKeySym();
if (key == "e" || key == "q" || key == "E" || key == "Q")
{
*status = false;
}
// Forward events
vtkInteractorStyleTrackballCamera::OnKeyPress();
}
public:
bool* status = nullptr;
};
vtkStandardNewMacro(KeyPressInteractorStyle);
```
} // namespace
int multiwindows()
{
auto simultaneousUpdate = false;
/_if ((argc \> 1) &&
(std::strin_///g(argv[1]) == “s” || std::string(argv[1]) == “S”))
{
simultaneousUpdate = true;
}
```
vtkNew colors;
// Have some fun with colors
std::vector renBkg{ "AliceBlue", "GhostWhite", "WhiteSmoke",
"Seashell" };
std::vector actorColor{ "Bisque", "RosyBrown", "Goldenrod",
"Chocolate" };
// Window sizes and spacing.
auto width = 300;
auto height = 300;
// Add extra space around each window.
auto dx = 20;
auto dy = 40;
auto w = width + dx;
auto h = height + dy;
std::vector> interactors;
std::vector> styles;
std::array running{ true, true, true, true };
vtkCamera* camera = nullptr;
auto sources = GetSources();
vtkNew mapperCommon;
mapperCommon->SetInputConnection(sources[1]->GetOutputPort());
vtkNew actorCommon;
actorCommon->SetMapper(mapperCommon);
actorCommon->SetOrientation(40, 40, 40);
for (unsigned int i = 0; i < 4; i++)
{
vtkNew renderWindow;
renderWindow->SetSize(width, height);
vtkNew renderer;
// Use the same initial camera for each renderer.
if (i == 0)
{
camera = renderer->GetActiveCamera();
camera->Azimuth(30);
camera->Elevation(30);
}
else
{
renderer->SetActiveCamera(camera);
}
renderWindow->AddRenderer(renderer);
vtkNew renderWindowInteractor;
interactors.push_back(renderWindowInteractor);
renderWindowInteractor->SetRenderWindow(renderWindow);
renderWindow->Render();
std::stringstream ss;
ss << "MultipleRenderWindows " << i;
renderWindow->SetWindowName(ss.str().c_str());
renderWindow->SetPosition((i % 2) * w, h - (i / 2) * h);
// Create a mapper and actor.
vtkNew mapper;
mapper->SetInputConnection(sources[i]->GetOutputPort());
vtkNew actor;
actor->SetMapper(mapper);
//actor->GetProperty()->SetColor(colors->GetColor3d(actorColor[i]).GetData());
renderer->AddActor(actor);
renderer->AddActor(actorCommon);
renderer->ResetCamera();
running[i] = true;
vtkNew style;
styles.push_back(style);
styles[i]->status = &running[i];
interactors[i]->SetInteractorStyle(styles[i]);
styles[i]->SetCurrentRenderer(renderer);
}
// Start the interaction.
if (simultaneousUpdate)
{
// Changes in any window will be simultaneously reflected in the other
// windows.
interactors[0]->Initialize();
// If all are running then process the commands.
while (std::all_of(running.begin(), running.end(),
[](bool i) { return i == true; }))
{
for (unsigned int i = 0; i < 4; i++)
{
if (running[i])
{
interactors[i]->ProcessEvents();
interactors[i]->Render();
}
else
{
interactors[i]->TerminateApp();
std::cout << "Window " << i << " has stopped running." << std::endl;
}
}
}
}
else
{
// Changes in any window will be reflected in the other
// windows when you click in the window.
interactors[0]->Start();
}
return EXIT_SUCCESS;
```
}
namespace {
std::vector\ GetSources()
{
std::vector\ sources;
for (unsigned i = 0; i \< 4; i++)
{
// Create a sphere.
vtkNew sphere;
sphere-\>SetCenter(0.0, 0.0, 0.0);
sphere-\>Update();
sources.push\_back(sphere);
// Create a cone.
vtkNew cone;
cone-\>SetCenter(0.0, 0.0, 0.0);
cone-\>SetDirection(0, 1, 0);
cone-\>Update();
sources.push\_back(cone);
// Create a cube.
vtkNew cube;
cube-\>SetCenter(0.0, 0.0, 0.0);
cube-\>Update();
sources.push\_back(cube);
// Create a cylinder.
vtkNew cylinder;
cylinder-\>SetCenter(0.0, 0.0, 0.0);
cylinder-\>Update();
sources.push\_back(cylinder);
}
return sources;
}
} // namespace
why?
---
### Author:  [@Hurmean](https://discourse.vtk.org/u/Hurmean)
#### Post date: [June 23, 2021, 5:42am UTC](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045/4 "2021-06-23T05:42:32Z")
when I use vtkGenericOpenGLRenderWindow and QVTKOpenGLNativeWidget instead doesn’t work