[Paraview] RE: [vtkusers] MangledMesa & VTK

[Sean Ziegeler]

> I've been alternately fighting with this same issue, and very happy with
> it. The residue it's left on my mind is: Use straight mesa without DRI.
> VTK_USE_OFFSCREEN causes trouble and doesn't fix anything. The examples
> use specific mesa opengl classes and that's not how to get offscreen
> rendering to work I was told to use the factories. Failing that you can
> always just run an xvfb process to provide a fake xserver.
> 
> I just went back and reran my little learn to do offscreen volume
> rendering program (attached). It works in an xterm but when I run it
> from the system console it whines that it can't connect to the X server.
> So I guess I'm also back to fighting with offscreen rendering just like
> you Randall.

It should be possible to do off-screen rendering with straight Mesa and
OSMesa, though I'm not sure if VTK is easily configured to do so
(haven't tried it).  Perhaps this how Sandia is doing it without Mangled
Mesa?

AFAIK, the purpose of Mangled Mesa is to avoid having to reconfigure
your system.  Mangled Mesa renames (mangles) all the function calls to
insure the OpenGL calls go to Mesa and not the system-installed
libGL.so.  Also, in VTK, when you turn on Mangled Mesa, it automatically
switches to OSMesa to do the off-screen rendering without X.

I would think straight Mesa + OSMesa would be a cleaner approach, and it
wouldn't require running xvfb every time either.

-Sean