[vtkusers] Re: MangledMesa & VTK

Wed Jan 3 09:16:42 EST 2007

On 1/3/07, Jeff Lee <jeff at cdnorthamerica.com> wrote:
>
>
>
> On 1/2/07, Berk Geveci <berk.geveci at kitware.com> wrote:
> >
> > I haven't looked at/used mangled mesa in a while. I used to enable it
> > on all my builds for testing but eventually gave it up. As Brian
> > mentioned, having a separate mesa build is more practical. There are
> > two maintenance issues with mangled mesa: 1. mangling support in the
> > mesa library itself, 2. mangled mesa support in VTK. (2) is not too
> > much of a burden although as Randall found out, it is not being tested
> > (therefore it may be considered broken). (1) is more of a problem
> > since Mesa folks are not really interested in it and do not test
> > mangled mesa. The last time I tried, the latest mesa could not be
> > built mangled. I think there are some users of mangled mesa out there
> > but I am not sure how many. Jeff Lee may be one of them.
>
>
> Hi All,
> Yes, we are using it to do offscreen rendering in an interactive client.
> The nice thing is that the same version of our rendering libraries work both
> in batch and interactive, but the same thing could be accomplished by having
> 2 builds of the rendering libs, as Berk said above (it would be nice if
> cmake produced the 2 different versions, instead of having completely
> separate builds).  In batch, osmesa seems to be the only real choice for
> rendering without an xserver, but interactive we can use glxpixmap, pbuffer,
> or fbo, so no real need to do mangled mesa when interactive to get higher
> resolution hardcopy.
>

I think that's part of the point here, you can do this without Mangling,
just using standard OSMesa.  Am I Wrong?

On another note, for what we're trying to do (and probably most people), it
> would be much more convenient to have an offscreen context in the
> renderwindow that we can just make current and use, instead of the
> SetOffscreenRendering() call.  The two scenarios I commonly see are you are
> either always rendering offscreen, or you are making a high-res hardcopy and
> don't want the current context to be messed with, but you don't really need
> to go through all that SetOffscreenRendering() does to accomplish that.
> Lets say you were creating an animation and wanted to save the animation as
> a higher resolution than the onscreen context - basically every frame you
> have to call SetOffscreenRendering to get your offscreen context to render
> to, and then you have to throw it away when you update the onscreen context
> - why not just add the ability for a vtkRenderWindow to have an additional
> (or many) context(s) to render into.
> -J
>
> -berk
> >
> > On 1/2/07, Moreland, Kenneth < kmorel at sandia.gov> wrote:
> > >
> > >
> > >
> > > I'm pretty sure the current use of this feature at Sandia is
> > zero.  All of
> > > our distributions of ParaView use either a hardware driver or straight
> > Mesa,
> > > not both.  As several other members of these lists have just
> > testified, it's
> > > much easier.
> > >
> > > Concerning the maintenance overhead of maintaining the mangled Mesa
> > stuff, I
> > > would rather have someone from Kitware speak to that since they are
> > really
> > > the ones doing that.  I recall Berk grumbling about it in the
> > past.  Perhaps
> > > he can elaborate.
> > >
> > > I also cannot speak for any other organizations that may be using
> > > VTK/ParaView.  If any of you out there use the vtkMesa* classes or
> > otherwise
> > > compile with the mangled Mesa features, now would be a really good
> > time to
> > > chime in.
> > >
> > > -Ken
> > >
> > >  ________________________________
> > >  From: paraview-bounces+kmorel= sandia.gov at paraview.org on behalf of
> > James P.
> > > Ahrens
> > > Sent: Sat 12/30/2006 4:35 PM
> > > To: paraview at paraview.org
> > > Cc: ahrens at lanl.gov
> > > Subject: [Paraview] Re: ParaView Digest, Vol 32, Issue 23
> > >
> > >
> > >
> > >
> > > > Message: 1
> > > > Date: Fri, 29 Dec 2006 09:05:35 -0600
> > > > From: "Randall Hand" < randall.hand at gmail.com>
> > > > Subject: Re: [Paraview] RE: [vtkusers] MangledMesa & VTK
> > > > To: "Sean Ziegeler" < seanzig at users.sourceforge.net>
> > > > Cc: paraview-developers at public.kitware.com, VTK Users
> > > >       < vtkusers at vtk.org>,     paraview at paraview.org
> > > > Message-ID:
> > > >
> > > < b02264720612290705h54bc20a6yf45d6b335f1f644e at mail.gmail.com>
> > > > Content-Type: text/plain; charset="iso-8859-1"
> > > > >
> > > > So maybe mangling isn't really necessary anymore, except for those
> > times
> > > > where you need to switch between Hardware OpengL & Mesa on the fly..
> > > > Anyone
> > > > actually doing that tho?
> > > >
> > >
> > > The original purpose of the mangled mesa extension was a heterogeneous
> >
> > > configuration with hardware acceleration and OS rendering at the same
> > > time. It was a long time ago, so I've forgotten the exact
> > configuration. I
> > > know SGI pipes were part of the mix. This was in the parallel VTK
> > days;
> > > ParaView did not exist, therefore no client/server architecture etc...
> > >
> > > One application is rendering extremely large offscreen imagery using
> > > mangled Mesa (limited by memory)  and hardware accelerated rendering
> > > smaller imagery for onscreen interactive use. This requires both
> > libraries
> > > in the same executable.
> > >
> > > Brian, what is the maintainence issue? What is the current cost etc.?
> > >
> > > --Jim
> > >
> > >
> > >
> > > _______________________________________________
> > > ParaView mailing list
> > > ParaView at paraview.org
> > > http://www.paraview.org/mailman/listinfo/paraview
> > >
> > >
> >
> >
> > --
> > Berk Geveci
> > Kitware Inc.
> > 28 Corporate Drive
> > Clifton Park, NY, 12309
> >
>
>
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-- 
----------------------------------------
Randall Hand
Visualization Scientist
ERDC MSRC-ITL
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