[osg-users] osgdem segmentation fault

Robert Osfield robert.osfield at gmail.com
Thu Sep 18 09:06:29 PDT 2008


Hi Ben,

This is almost certainly a driver bug.  Have a look at the support
sits for the Intel hardware to see if there is any reports about
problems with pbuffers/FBO's and any fixes that can be applied.

In terms of workarounds, osgdem requires a graphics context, so could
probably just use a standard graphics window, and it'll actually do
this automatically if pbuffers aren't supported, but in your case it
looks like GLX is claiming they are supported so OSG/VPB then goes are
tries to create one and then it crashes because of a bug in the
driver.  You could comment out the code that tries pbuffers, this is
just a hack though and not something suitable for merging with SVN.

The other solution is a hardware one - go buy yourself a cheap Nvidia
card, plugin it in, enable the NVidia drivers and you'll be away.
You'll get loads of performance, even on load end hardware and driver
quality and features are way better.

Robert.

On Thu, Sep 18, 2008 at 4:53 PM, benben <benhongh at gmail.com> wrote:
> Robert Osfield wrote:
>>
>> Hi Ben,
>>
>> The stack trace suggests a problems with pbuffers, which could well be
>> a GLX/OpenGL driver bug.  What hardware and OpenGL drivers are you
>> working with?
>
> Hardware: Intel Integrated Graphics G965
> Driver:   The Intel graphics driver (intelfb.ko)
> OS Kernel: Linux 2.6.24, if this matters.
>
>>
>> Could you try :
>>
>>    osgprerender cow.osg --pbuffer.
>
> This results in segmentation fault. Even without the --pbuffer option it
> results in segmentation fault.
>
> So yes sorry for bothering you much Rob. It is not a osgdem bug. However, it
> will be great if you can suggest a workaround or solution.
>
>>
>>
>> As for compiling from source it should just be a case of :
>>
>>    cd OpenSceneGraph
>>    ./configure
>>    make
>>    sudo make install
>>
>> The paths to the plugins should just work automatically.  If you don't
>> install in standard system directory then you'd need to use
>> LD_LIBRARY_PATH to the point to the parent directory of the plugins
>> directory.
>>
>> VPB 1.0 will be released against OSG-2.8, which obviously isn't out
>> yet... perhaps by end of October it'll be ready.  Prior to that VPB
>> 0.9.9+ and the 1.0 pre releases will map to OSG-2.7.x dev releases.
>>
>> Robert.
>>
>> On Thu, Sep 18, 2008 at 2:35 PM, benben <benhongh at gmail.com> wrote:
>>>
>>> Robert Osfield wrote:
>>>>
>>>> Hi Ben,
>>>>
>>>> Thanks for the extra info.   The segfault without any options suggests
>>>> a build issue or link issue of some kind.
>>>>
>>>> Could you provide the stack trace?
>>>
>>> Sure, the core file reads
>>>
>>> #0  0x00007fa215d13af2 in ?? () from /usr/lib/libGL.so.1
>>> #1  0x00007fa216c730d9 in osgViewer::PixelBufferX11::init ()
>>>  from /usr/lib/libosgViewer.so.6
>>> #2  0x00007fa216c73788 in osgViewer::PixelBufferX11::PixelBufferX11 ()
>>>  from /usr/lib/libosgViewer.so.6
>>> #3  0x00007fa216c6fd27 in
>>> X11WindowingSystemInterface::createGraphicsContext
>>> ()
>>>  from /usr/lib/libosgViewer.so.6
>>> #4  0x000000000040ae91 in main ()
>>>
>>> It seems it's more of a OSG/OpenGL problem than a osgdem related one. But
>>> I
>>> have been writing a few OSG apps and they don't seem to have any segfault
>>> problems. If it is in fact non-osgdem related, you have my apology.
>>>
>>>> VPB and OSG have come along way since 0.9.1 and OSG-2.2 respectively,
>>>> and this week I'll be make dev releases for both VPB and OSG that will
>>>> be matched so these would be a good place to move up to.   VPB itself
>>>> is pretty near its 1.0 status, just a few more weeks left development
>>>> wise.
>>>>
>>> The only reason I didn't installed the lastest VPB is that I don't want
>>> to
>>> rebuild OSG from source. I tried, but despite my best effort to set
>>> environment variables I could't get it to load plug-ins. As my project
>>> deadline is closing in I'd play safe with the working 2.2 OSG
>>> installation.
>>>
>>> I will give OSG2.6 / VPN1.0 a shot once my project is over.
>>>
>>>> Robert.
>>>
>>> Thanks,
>>>
>>> Ben
>>>
>>>
>>>> On Wed, Sep 17, 2008 at 2:58 PM, benben <benhongh at gmail.com> wrote:
>>>>>
>>>>> Robert Osfield wrote:
>>>>>>
>>>>>> Hi Ben,
>>>>>>
>>>>>> I'm afraid there is waaaay too little info about your setup to provide
>>>>>> any real guidance.  VPB should just compile against an installed OSG
>>>>>> without need for configuration.
>>>>>>
>>>>>> You don't mention which VPB or OSG version your are using, you also
>>>>>> make no mention of the platform or compilers.  All this is important
>>>>>> to understanding what might go wrong and how to fix it.
>>>>>
>>>>> Sorry for the lack of information. The OSG version is 2.2 and the VPB
>>>>> version is 0.9.1. I am running a Ubuntu Linux 8.04 64bit on an Intel
>>>>> platform, if this is also relevant.
>>>>>
>>>>> The osg installation is straight from the Ubuntu package repository
>>>>> (binary
>>>>> install, as opposed to local rebuild).
>>>>>
>>>>> For building the VPB I added an extra line to the CMakeLists.txt
>>>>>
>>>>>  SET(GDAL_INCLUDE_DIR /usr/include/gdal)
>>>>>
>>>>> so osgdem can be compiled.
>>>>>
>>>>> I followed the standard
>>>>>
>>>>>  ./configure
>>>>>  make
>>>>>  sudo make install
>>>>>
>>>>> Everything seemed to be ok. For some reason my OS does not put 64bit
>>>>> libraries in /usr/local/lib64, where the VPB libraries are, so I
>>>>>
>>>>>  export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib64
>>>>>
>>>>> This stops the "cannot find shared object" error from the loader.
>>>>>
>>>>> And on executing
>>>>>
>>>>>  osgdem
>>>>>
>>>>> with no arguments, it simply quits with a segmentation fault error.
>>>>>
>>>>> I also followed the VPB tutorial at
>>>>>
>>>>> http://www.openscenegraph.org/projects/VirtualPlanetBuilder
>>>>>
>>>>> and despite the extra argument inputs I have the same error. So I
>>>>> reckon
>>>>> I
>>>>> must have configured VPB wrong somehow.
>>>>>
>>>>> Is there anything I overlooked?
>>>>>
>>>>> Regards
>>>>> Ben
>>>>>
>>>>> _______________________________________________
>>>>> osg-users mailing list
>>>>> osg-users at lists.openscenegraph.org
>>>>>
>>>>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>>>>>
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