[vtkusers] Error using vtkOpenGLGPUVolumeRayCastMapper on OS X

[Sean McBride]

On Thu, 24 Mar 2016 12:46:34 -0500, David Warren said:

>ERROR: In
>/Users/ilan/minonda/conda-bld/work/VTK-6.3.0/Rendering/VolumeOpenGL/
>vtkOpenGLGPUVolumeRayCastMapper.cxx,
>line 4040
>vtkOpenGLGPUVolumeRayCastMapper (0x103b90000): Rendering failed because the
>following OpenGL extensions are required but not supported:  Disabled on
>Apple OS X Snow Leopard with nVidia.

If you search the VTK codebase for "Snow Leopard with nVidia" and dig through git history, we find commit 08abcf15a5a333096f406dfe5b34d2b7bc47bdf8.  See:

<https://github.com/Slicer/VTK/commit/add058e>

Seems it's a workaround for an OS X 10.6 (Snow Leopard) bug that was apparently fixed in 10.7 (Lion).  The code does a fragile check that's probably failing for you.

Actually, I think the check was recently broken in 56a17fafa4e389058c89401bdffd524ba873e622 by Max (cc'ed).

Do you have an nVidia, AMD/ATI, or Intel GPU?

I'll make a patch to clean it all up...

Cheers,

-- 
____________________________________________________________
Sean McBride, B. Eng                 sean at rogue-research.com
Rogue Research                        www.rogue-research.com 
Mac Software Developer              Montréal, Québec, Canada