[Bf-committers] WITH_HEADLESS and OpenGL

[Jacob Merrill]

Running blender headless = as a background process right?

Could you use this + game engine, to send data to the headless version, and
send back models via libLoad?

Agoose has done this with a "running copy" of blender, but could you do it
with a headless version of blender launched by the blenderPlayer?

Destructive terrain modification, in game modeling etc?

*I can imagine an amazing version of blender verse....*


On Fri, Dec 12, 2014 at 1:13 PM, Carroll, Michael R <
michael.r.carroll at intel.com> wrote:
>
> Great, thank you for the feedback Campbell. I'll be taking a closer look
> at the first two options.
>
>
> -MichaelC
>
> -----Original Message-----
> From: Campbell Barton [mailto:ideasman42 at gmail.com]
> Sent: Thursday, December 11, 2014 4:16 PM
> To: Carroll, Michael R
> Cc: bf-committers at blender.org
> Subject: Re: WITH_HEADLESS and OpenGL
>
> On Thu, Dec 11, 2014 at 11:26 PM, Carroll, Michael R <
> michael.r.carroll at intel.com> wrote:
> > Hello BF-Committers,
> >
> >
> >
> > Does building Blender WITH_HEADLESS require linkage with OpenGL?
>
> Currently yes, however it could be changed.
>
> With headless builds (and in background mode) OpenGL arent called, there
> are a few possible workaround.
>
> - Use mesa software OpenGL (we use this for blender-softwaregl on Linux),
> ... Not a real solution, but at least you don't need to install libs on the
> operating system.
>
> - Stub-out OpenGL and link to a dummy library.
> ... No heavy dependencies, but takes some effort to setup. It could be
> preloaded or static link.
>
> - Omit all GL calls from WITH_HEADLESS builds, ... the most correct
> solution, but likely disruptive to the current code-base. maybe interesting
> to try, but likely to add a lot if #ifdef's. Since this is a build option
> (not even included in official builds), its not such an attractive prospect
> to insert 100's of ifdef's all over the code.
>
> Longer term we might move drawing code into our own GPU module, IIRC Jason
> Wilkins work went some way towards this, in that case its probably  less
> trouble to stub out the drawing calls and remove the OpenGL dependency.
>
>
> > I have read the renderer doesn’t leverage OpenGL at all. I see the
> > window
> > manager/X11 features have been disabled in the WITH_HEADLESS source.
> > However, I attempt to compile (using CMAKE) without any of the
> > WITH_GL_PROFILE* options and bump into OpenGL related compiler errors.
> > They start with the second editors/ object:
> >
> >
> >
> > [  5%] Building C object
> > source/blender/editors/armature/CMakeFiles/bf_editor_armature.dir/edit
> > armature_sketch.c.o
> >
> >
> /blender/blender/source/blender/editors/armature/editarmature_sketch.c:441:26:
> > error: unknown type name ‘GLUquadric’
> >
> > static void sk_drawPoint(GLUquadric *quad, SK_Point *pt, float size)
> >
> >
> >
> > Would OpenGL have to be shimmed out or is there a build toggle to
> > remove OpenGL?
> >
> > Many sources in the editors/ folders appear to use OpenGL… can these
> > specifically be removed from a WITH_HEADLESS build?
> >
> >
> >
> > I have been lurking on the mail list reading related conversations…
> > starting with the March’11 thread with Campbell, Brecht, and Pete.
> > Campbell suggested that adding the WITH_HEADLESS feature could negate
> > the requirement for OpenGL. I have seen a lot of checkins to support
> > WITH_HEADLESS but those same diffs don’t appear to remove OpenGL from
> the build flow.
> >
> >
> >
> > I’m looking to run Blender for performance analysis on many different
> > platforms. Eliminating any GUI is a requirement. Removing OpenGL would
> > also be extremely helpful.
> >
> >
> >
> > Thank you,
> >
> > -MichaelC
> >
> >
>
>
>
> --
> - Campbell
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