[vtkusers] Qt5/VTK application does not start correctly (with X11 forwarding)

[Sophonet]

I think I found the problem: My XMing version (6.9.0.31 from 2007, the 
last free version) seemed to be too old. I have switched to Cygnus/X, 
and when turning off native OpenGL, the application starts fine.

Thanks for pointing me to the right direction.


On 2017-08-11 17:09, David Gobbi wrote:
> Ah, I missed that.  On the linux system, use "ldd" to verify that the
> VTK libraries are linked to the correct OpenGL libraries:
> 
>   ldd /path/to/vtk/library.so
> 
> Also, as an alternative to X11 forwarding, you can try using VNC.  In
> the past, I've set up Xvnc to allow multiple users to connect to a
> linux server and get a graphical linux desktop:
> 
> http://www.hep.phy.cam.ac.uk/vnc_docs/xvnc.html
> 
>  - David
> 
> On Fri, Aug 11, 2017 at 8:25 AM, Sophonet
> <vtk12af6bc42 at kant.sophonet.de> wrote:
> 
>> Ah okay, this was not clear to me. But see bottom my first e-mail:
>> Mesa is doing software rendering (llvmpipe), no GPU should be
>> required.
>> 
>> On 2017-08-11 16:13, David Gobbi wrote:
>> 
>> The "-X" vs "-Y" doesn't mean encrypted vs. non-encrypted.  See the
>> ssh man page here:
>> 
>> https://man.openbsd.org/ssh
>> 
>> Specifically:   -Y    Enables trusted X11 forwarding.
>> 
>> The "-Y" gives the client access to the GPU, and is necessary for
>> all
>> but the most basic rendering.  I'm not sure if putty provides this
>> option, since I do nearly all of my work on Linux or Mac.
>> 
>> - David
>> 
>> On Fri, Aug 11, 2017 at 7:52 AM, Sophonet
>> <vtk12af6bc42 at kant.sophonet.de> wrote:
>> 
>> Yes, well, I am using a Windows machine and putty. Putty has an
>> option in it's configuration dialog. I don't know whether the X
>> connection is encrypted (-X) or not (-Y).
>> 
>> On 2017-08-11 14:31, David Gobbi wrote:
>> How are you doing the X11 forwarding?  Are you using "ssh -Y"?
>> 
>> On Fri, Aug 11, 2017 at 6:20 AM, Sophonet
>> <vtk12af6bc42 at kant.sophonet.de> wrote:
>> 
>> Hi list,
>> 
>> an application using VTK 8.0.0 and Qt 5.9.1 (built with -opengl
>> desktop) does not start correctly (using X11 forwarding). After
>> displaying an error message "failed to get the current screen
>> resources", there is another error message
>> 
>> vtkXOpenGLRenderWindow (0x55f891d77a80): GL version 2.1 with the
>> gpu_shader4 extension is not supported by your graphics driver but
>> is required for the new OpenGL rendering backend. Please update your
>> OpenGL driver. If you are using Mesa please make sure you have
>> version 10.6.5 or later and make sure your driver in Mesa supports
>> OpenGL 3.2.
>> 
>> However, my Ubuntu 17.04 system has Mesa 17.0.7, glxgears works fine
>> (using X11 forwarding) and glxinfo shows (among other things) the
>> correct driver - see below, so I am a bit puzzled what is going on.
>> Any hints?
>> 
>> Thanks,
>> 
>> sophonet
>> 
>> P.S.: The first call in my application's main() function is
>> QSurfaceFormat::setDefaultFormat, see below. The same application
>> runs fine and without problems on Windows.
>> 
>> #if QT_VERSION >= 0x050500
>> // before initializing QApplication, set the default surface
>> format, see documentation
>> 
>> QSurfaceFormat::setDefaultFormat(QVTKOpenGLWidget::defaultFormat());
>> #endif
>> 
>> GLX version: 1.2
>> GLX extensions:
>> GLX_ARB_get_proc_address, GLX_ARB_multisample,
>> GLX_EXT_import_context,
>> GLX_EXT_visual_info, GLX_EXT_visual_rating,
>> GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer,
>> GLX_OML_swap_method, GLX_SGIS_multisample, GLX_SGIX_fbconfig,
>> GLX_SGI_make_current_read
>> Extended renderer info (GLX_MESA_query_renderer):
>> Vendor: VMware, Inc. (0xffffffff)
>> Device: llvmpipe (LLVM 4.0, 128 bits) (0xffffffff)
>> Version: 17.0.7
>> Accelerated: no
>> Video memory: 3949MB
>> Unified memory: no
>> Preferred profile: core (0x1)
>> Max core profile version: 3.3
>> Max compat profile version: 3.0
>> Max GLES1 profile version: 1.1
>> Max GLES[23] profile version: 3.0
>> OpenGL vendor string: VMware, Inc.
>> OpenGL renderer string: Gallium 0.4 on llvmpipe (LLVM 4.0, 128 bits)
>> OpenGL version string: 3.0 Mesa 17.0.7
>> OpenGL shading language version string: 1.30
>> 
>> ______________________________________________