[vtkusers] Is -DVTK_RENDERING_BACKEND=OpenGL needed for Haswell with 7.0.0?

Sun Jun 26 05:42:30 EDT 2016

2016-06-26 11:05 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:

> 2016-06-26 11:01 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
>
>> 2016-05-25 17:08 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
>>
>>> 2016-05-25 13:49 GMT+02:00 Ken Martin <ken.martin at kitware.com>:
>>>
>>>> Yes, you should be fine with VTK 7.0, OpenGL2 and Haswell.  - Ken
>>>>
>>>
>> Hm, initially it seemed like things were working fine. I was using the
>> GPU based volume mapper without problems (using a modified
>> QVTKRenderWindowInteractor), and I _think_ I was using the OpenGL2 backend
>> (how can I tell btw?).
>>
>> But now, as I started trying to make a QOpenGLWidget-based Qt<->VTK
>> adapter class instead, I get the following when trying to initialize the
>> render window:
>>
>> ERROR: In
>> /home/estan/Blandat/vtk-python3/src/VTK-7.0.0/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx,
>> line 545
>> vtkGenericOpenGLRenderWindow (0x205fb10): 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.
>>
>> And sure enough:
>>
>> estan at newton:~$ glxinfo | grep "OpenGL version"
>> OpenGL version string: 3.0 Mesa 11.2.0
>>
>> However:
>>
>> estan at newton:~$ glxinfo | grep "OpenGL core profile version"
>> OpenGL core profile version string: 3.3 (Core Profile) Mesa 11.2.0
>>
>> I'm a little unsure about which of these version numbers I should be
>> looking at to see if my graphics has what it takes.
>>
>> Also, I'm now even unsure if I was ever using the OpenGL2 backend..
>> perhaps VTK was falling back to OpenGL1 somehow, and that's why it worked
>> in the beginning? Or is the selection of backend always a compile time
>> thing?
>>
>> I build my VTK 7.0.0 in a Personal Package Archive at:
>>
>>     https://launchpad.net/~elvstone/+archive/ubuntu/vtk7
>>
>> and the full build log is at:
>>
>>
>> https://launchpadlibrarian.net/261625779/buildlog_ubuntu-xenial-amd64.vtk7_7.0.0-0ubuntu2_BUILDING.txt.gz
>>
>
> Okay, so looking at that build log, I see:
>
> -- Setting rendering backend to 'OpenGL2' as none was specified.
> -- Backend OpenGL modules: vtkRenderingContextOpenGL;vtkRenderingOpenGL;vtkRenderingLIC;vtkRenderingVolumeOpenGL;vtkRenderingGL2PS
> -- Backend OpenGL2 modules: vtkRenderingContextOpenGL2;vtkRenderingVolumeOpenGL2;vtkRenderingOpenGL2;vtkRenderingLICOpenGL2;vtkDomainsChemistryOpenGL2
> -- Enabling modules for OpenGL2.
>
>
> Does this mean I'll always be using the OpenGL2 backend, or that OpenGL vs
> OpenGL2 is a runtime choice?
>

I've now done some testing here at home, on my old Sandybridge laptop which
I think only has a HD 3000 graphics chip:

[estan at pyret ~]$ glxinfo | grep "OpenGL version"
OpenGL version string: 3.0 Mesa 11.2.2

and the "Extended renderer info" section says:

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel Open Source Technology Center (0x8086)
    Device: Mesa DRI Intel(R) Sandybridge Mobile  (0x126)
    Version: 11.2.2
    Accelerated: yes
    Video memory: 1536MB
    Unified memory: yes
    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

And it turns out that all I had to do in my little QOpenGLWidget-adapter
was:

        surfaceFormat.setMajorVersion(3)
        surfaceFormat.setMinorVersion(2)
        surfaceFormat.setProfile(QSurfaceFormat.CompatibilityProfile)
        self.setFormat(surfaceFormat)

to request OpenGL 3.2 compatibility profile. After this I no longer get the
error and rendering seems to work.

I'm actually a little surprised this works, since I didn't think my old
home laptop would support the OpenGL2 backend. And the glxinfo output shows
"Max compat profile version: 3.0". But printing the
.format().majorVersion() and .format().minorVersion() after setting it on
the QOpenGLWidget confirms that I've gotten the 3.2 format set.

Oh well, I'm happy now, but would still like some clarification from
someone who knows more than me about these things.

Elvis

> Elvis
>
>
>>
>> Any advice is much appreciated!
>>
>> I'm considering switching to the old OpenGL1 backend anyway, since I
>> realized my laptop at home only has a Sandybridge chipset (at work it's
>> Haswell), and it's convenient to be able to do some work from my home
>> laptop. But I'd like to know why I get the above error on my work laptop,
>> since I thought it'd be compatible.
>>
>> Elvis
>>
>>
>>> Great, thanks!
>>>
>>> Elvis
>>>
>>>
>>>>
>>>> On Wed, May 25, 2016 at 4:50 AM, Elvis Stansvik <
>>>> elvis.stansvik at orexplore.com> wrote:
>>>>
>>>>> Hi all,
>>>>>
>>>>> I'm about to try a compile of VTK 7.0.0 release on Ubuntu 16.04
>>>>> (Xenial).
>>>>>
>>>>> The machine where I need this to run has a Haswell Intel graphics chip
>>>>> (Intel(R) HD Graphics 4400), which supports the OpenGL 3.3 profile. Will
>>>>> the new OpenGL backend (the version in 7.0.0) support this graphics card,
>>>>> or will I need to use the old backend with -DVTK_RENDERING_BACKEND=OpenGL?
>>>>>
>>>>> I read that support for is for Ivy Bridge and later in 7.0.0, so I
>>>>> think I should be OK right?
>>>>>
>>>>> Thanks in advance,
>>>>> Elvis
>>>>>
>>>>> _______________________________________________
>>>>> Powered by www.kitware.com
>>>>>
>>>>> Visit other Kitware open-source projects at
>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>
>>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>>
>>>>> Search the list archives at: http://markmail.org/search/?q=vtkusers
>>>>>
>>>>> Follow this link to subscribe/unsubscribe:
>>>>> http://public.kitware.com/mailman/listinfo/vtkusers
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Ken Martin PhD
>>>> Chairman & CFO
>>>> Kitware Inc.
>>>> 28 Corporate Drive
>>>> Clifton Park NY 12065
>>>> 518 371 3971
>>>>
>>>> This communication, including all attachments, contains confidential
>>>> and legally privileged information, and it is intended only for the use of
>>>> the addressee.  Access to this email by anyone else is unauthorized. If you
>>>> are not the intended recipient, any disclosure, copying, distribution or
>>>> any action taken in reliance on it is prohibited and may be unlawful. If
>>>> you received this communication in error please notify us immediately and
>>>> destroy the original message.  Thank you.
>>>>
>>>
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20160626/a75e980c/attachment.html>