# vtkGPUVolumeRayCastMapper and Qt (bug?)
**URL:** https://discourse.vtk.org/t/vtkgpuvolumeraycastmapper-and-qt-bug/1640
**Category:** Development
**Created:** [August 23, 2019, 10:16am UTC](https://discourse.vtk.org/t/vtkgpuvolumeraycastmapper-and-qt-bug/1640 "2019-08-23T10:16:55Z")
**Posts on this page:** 1
**Page:** 1
### Author:  [@Romain](https://discourse.vtk.org/u/Romain)
#### Post date: [August 23, 2019, 10:16am UTC](https://discourse.vtk.org/t/vtkgpuvolumeraycastmapper-and-qt-bug/1640/1 "2019-08-23T10:16:55Z")
Hello everyone,
I’m working on Windows 10 1903, with Visual Studio 2017 (19.16.27031.1), VTK 8.2 and Qt 5.12.4.
My graphic cards is a RTX 2080 Max-Q and the Nvidia driver version is 431.70.
I try to use vtkGPUVolumeRayCastMapper inside a Qt window.
I test the example MedicalDemo4 by replacing vtkFixedPointVolumeRayCastMapper by vtkGPUVolumeRayCastMapper and it’s working great inside a VTK Window.
After that, I used the RenderWindowNoUiFile example and add the vtkVolume to the renderer.
But I have the following error:
```auto
ERROR: In D:\LIBS\_sources\vtk\Rendering\OpenGL2\vtkTextureObject.cxx, line 1991
vtkTextureObject (00000226BA9BFEA0): failed at glCopyTexImage2D 33191 1 OpenGL errors detected
0 : (1282) Invalid operation
```
I attached you the code that I used and also the CMake file (Maybe I miss some libraries but I’m not sure).
[main.cpp](https://discourse.vtk.org/uploads/short-url/eY0GauIRP1yIoGKzQLWhOLmMx79.cpp) (6.0 KB)
[CMakeLists.txt](https://discourse.vtk.org/uploads/short-url/98DcgJn8ox3Riw6BFYI1fzPrEL6.txt) (1.7 KB)
Edit:
I print the Qt current context format (OpenGL seems well loaded):
```auto
QSurfaceFormat(version 3.2, options QFlags(), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 8, stencilBufferSize 8, samples 0, swapBehavior QSurfaceFormat::DoubleBuffer, swapInterval 1, colorSpace QSurfaceFormat::sRGBColorSpace, profile QSurfaceFormat::CoreProfile)
```