# VtkRenderer error
**URL:** https://discourse.vtk.org/t/vtkrenderer-error/6143
**Category:** Support
**Created:** [July 6, 2021, 7:50pm UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143 "2021-07-06T19:50:46Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Synfony](https://discourse.vtk.org/u/Synfony)
#### Post date: [July 6, 2021, 7:50pm UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143/1 "2021-07-06T19:50:47Z")
Hi,
I am getting “Re-setting view-up since view plane normal is parallel” runtime error message arising from …\Rendering\Core\vtkRenderer.cxx line 1175
This error message is showing when I move the outline box to view the top of the box. (screenshot attached)
I am using VTK8.2.
Is there any way to suppress/resolve this message?
Thanks.
---
### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 7, 2021, 6:12pm UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143/2 "2021-07-07T18:12:09Z")
Hi there,
To achieve that effect one can, for instance, rotate the camera around the box. Do you have code that moves your camera? I’m asking this because I’ve seen camera-moving code lacking a due update of the view-up vector (done via `vtkCamera::SetViewUp()`) as many people think it is done automatically. My project has such code (e.g. to reset the scene to look down the X axis) and I have always to update it to get it right:
```cpp
´void View3DWidget::onLookAtXY()
{
//_renderer->ResetCamera();
double *fp = _rendererMainScene->GetActiveCamera()->GetFocalPoint();
double *p = _rendererMainScene->GetActiveCamera()->GetPosition();
double dist
= std::sqrt((p[0] - fp[0]) * (p[0] - fp[0]) + (p[1] - fp[1]) * (p[1] - fp[1])
+ (p[2] - fp[2]) * (p[2] - fp[2]));
_rendererMainScene->GetActiveCamera()->SetPosition(fp[0], fp[1], fp[2] + dist);
_rendererMainScene->GetActiveCamera()->SetViewUp(0.0, 1.0, 0.0);
// redraw the scene
_vtkwidget->GetRenderWindow()->Render();
}
```
regards,
Paulo
---
### Author:  [@Synfony](https://discourse.vtk.org/u/Synfony)
#### Post date: [July 8, 2021, 3:46am UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143/3 "2021-07-08T03:46:04Z")
Many thanks you Paulo.
It worked! 👍
---
### Author:  [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [July 8, 2021, 12:49pm UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143/4 "2021-07-08T12:49:35Z")
Hello,
I’m glad to help. Here’s the role of the view-up vector if I was not very clear:
As you can see, setting only the camera’s focal point (“orientation” in the figure above) and position is not enough to define the viewing geometry. The view-up vector tells the renderer where the “up” of the camera is pointing to. The view-up vector should, under normal circumstances, be orthogonal to the normal vector of viewing plane (the blue panel in the figure). Setting it parallel to the normal would result in ill-conditioned matrices and divisions by zero in the computations down the rendering pipeline. Hence the VTK error.
take care,
Paulo
---
### Author:  [@Synfony](https://discourse.vtk.org/u/Synfony)
#### Post date: [July 8, 2021, 3:23pm UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143/5 "2021-07-08T15:23:44Z")
You have summarized it very clearly and yet so precise 👌