[vtkusers] Offscreen rendering bug

[Francois Bertel]

So I cannot reproduce what you said.

I tried compiling VTK against Mesa with VTK_OPENGL_HAS_OSMESA  to OFF and it crashes.

But if I set VTK_OPENGL_HAS_OSMESA to ON, it does not crash.

John Norris wrote:
> Yes, that's right.  I was trying to explain that I was using only Mesa 
> (including OSMesa) and not OpenGL + MangledMesa.  Sorry I didn't make 
> that clearer.
> 
> John
> 
> Francois Bertel wrote:
>> Hi John,
>>
>> By including OSMesa, do you really mean you set VTK_OPENGL_HAS_OSMESA 
>> to ON?
>>
>> John Norris wrote:
>>> Hi,
>>>
>>> I've compiled VTK (from CVS) using Mesa-7.0.3 (including OSMesa) on a
>>> x86_64 linux system.  I've called
>>> vtkGraphicsFactory::SetOffScreenOnlyMode(1)
>>> before creating any of the rendering classes.  I've also called
>>> OffScreenRenderingOn() from my render window before doing anything else
>>> with it.  Still, VTK tries to contact the X server, causing a crash.  It
>>> seems to be happening after line 496 in vtkOpenGLExtensionManager, in
>>> the #ifdef VTK_USE_X block.  The call to
>>> this->RenderWindow->GetGenericDisplayId() leads to a call to
>>> XOpenDisplay(); XOpenDisplay() is explicitly called just a few lines
>>> later, but my program doesn't get that far.
>>>
>>> Perhaps the return value of vtkGraphicsFactory::GetOffScreenOnlyMode()
>>> or this->RenderWindow->GetOffScreenRendering() should be checked first.
>>>
>>> Thanks,
>>> John
>>
>>
> 


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François Bertel, PhD  | Kitware Inc. Suite 204
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