# Opacity issue in QVTKOpenGLWidget and PCL Visualizer
**URL:** https://discourse.vtk.org/t/opacity-issue-in-qvtkopenglwidget-and-pcl-visualizer/9646
**Category:** Support
**Created:** [October 19, 2022, 6:45am UTC](https://discourse.vtk.org/t/opacity-issue-in-qvtkopenglwidget-and-pcl-visualizer/9646 "2022-10-19T06:45:13Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Panda12197](https://discourse.vtk.org/u/Panda12197)
#### Post date: [October 19, 2022, 6:45am UTC](https://discourse.vtk.org/t/opacity-issue-in-qvtkopenglwidget-and-pcl-visualizer/9646/1 "2022-10-19T06:45:13Z")
I am trying to set the opacity for Cube in pclviewer with surface. It is successed but I can not set the opacity value.
**It is OK when the opacity value is 1.0 but any values less than 1.0 make it invisible**.
The program is as following:
> viewer-\>addCube(Eigen::Vector3f(c\_x,c\_y,c\_z),Eigen::Quaternionf(rotation),w,d,h,“cube”);
> viewer-\>setShapeRenderingProperties (pcl::visualization::PCL\_VISUALIZER\_COLOR, 0.0, 1.0, 0.0, “cube”);
> viewer-\>setShapeRenderingProperties (pcl::visualization::PCL\_VISUALIZER\_REPRESENTATION
> ,pcl::visualization::PCL\_VISUALIZER\_REPRESENTATION\_SURFACE,“cube”);
> viewer-\>setShapeRenderingProperties(PCL\_VISUALIZER\_OPACITY,0.5,“cube”);
When I run the program, I got the following error:
> ERROR: In /home/VTK-8.2.0/Rendering/OpenGL2/vtkShaderProgram.cxx, line 446
> vtkShaderProgram (0x55d9fb9540): 1:#version 300 es
> 2: #ifndef GL\_ES
> 3: #define highp
> 4: #define mediump
> 5: #define lowp
> 6: #endif // GL\_ES
> 7: #define attribute in
> 8: #define varying out
> 9:
> 10:
> 11: /_=========================================================================
> 12:
> 13: Program: Visualization Toolkit
> 14: Module: vtkPolyDataVS.glsl
> 15:
> 16: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
> 17: All rights reserved.
> 18: See Copyright.txt or [http://www.kitware.com/Copyright.htm](http://www.kitware.com/Copyright.htm) for details.
> 19:
> 20: This software is distributed WITHOUT ANY WARRANTY; without even
> 21: the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
> 22: PURPOSE. See the above copyright notice for more information.
> 23:
> 24: =========================================================================_/
> 25:
> 26: in vec4 vertexMC;
> 27:
> 28: // frag position in VC
> 29: out vec4 vertexVCVSOutput;
> 30:
> 31: // optional normal declaration
> 32: //VTK::Normal::Dec
> 33:
> 34: // extra lighting parameters
> 35: //VTK::Light::Dec
> 36:
> 37: // Texture coordinates
> 38: //VTK::TCoord::Dec
> 39:
> 40: // material property values
> 41: //VTK::Color::Dec
> 42:
> 43: // clipping plane vars
> 44: //VTK::Clip::Dec
> 45:
> 46: // camera and actor matrix values
> 47: uniform mat4 MCDCMatrix;
> 48: uniform mat4 MCVCMatrix;
> 49:
> 50: // Apple Bug
> 51: //VTK::PrimID::Dec
> 52:
> 53: // Value raster
> 54: //VTK::ValuePass::Dec
> 55:
> 56: // picking support
> 57: //VTK::Picking::Dec
> 58:
> 59: void main()
> 60: {
> 61: //VTK::Color::Impl
> 62:
> 63: //VTK::Normal::Impl
> 64:
> 65: //VTK::TCoord::Impl
> 66:
> 67: //VTK::Clip::Impl
> 68:
> 69: //VTK::PrimID::Impl
> 70:
> 71: vertexVCVSOutput = MCVCMatrix \* vertexMC;
> 72: gl\_Position = MCDCMatrix \* vertexMC;
> 73:
> 74:
> 75: //VTK::ValuePass::Impl
> 76:
> 77: //VTK::Light::Impl
> 78:
> 79: //VTK::Picking::Impl
> 80: }
> ERROR: In /home/VTK-8.2.0/Rendering/OpenGL2/vtkShaderProgram.cxx, line 447
> vtkShaderProgram (0x55d9fb9540):
I am using PCL-1.12.1, VTK-8.2 and Qt5.
---
### Author:  [@nnw](https://discourse.vtk.org/u/nnw)
#### Post date: [October 21, 2022, 2:53am UTC](https://discourse.vtk.org/t/opacity-issue-in-qvtkopenglwidget-and-pcl-visualizer/9646/2 "2022-10-21T02:53:23Z")
I also get the same error while using either “#version 320 es” or “#version 150”.
Is there any way to find compatible version for glsl?
It works fine with vtk6.3 but not in vtk8.2.0.
Here is my opengl version.
