On Windows, create a graphics context with the pbuffer flag set to true
and windowDecoration set to false.
osg::ref_ptr<osg::GraphicsContext::Traits> traits = new
osg::GraphicsContext::Traits;
traits->x = 0;
traits->y = 0;
traits->width = 640;
traits->height = 480;
traits->red = 8;
traits->green = 8;
traits->blue = 8;
traits->alpha = 8;
traits->windowDecoration = false;
traits->pbuffer = true;
traits->doubleBuffer = false; // or true as needed
traits->sharedContext = 0;
m_pbuffer =
osg::GraphicsContext::createGraphicsContext(traits.get());
if (!m_pbuffer.valid())
{
osg::notify(osg::NOTICE) << "Pixel buffer has not been created
successfully. NOTE: update your dependencies folder if you see this error!"
<< std::endl;
exit(1);
}
else
{
// Create an osgViewer running on top of a pbuffer graphics
context
m_viewer = new osgViewer::Viewer();
// in my case I use a slave camera with ortho projection
// to render whatever is needed
m_camera = new osg::Camera;
m_camera->setGraphicsContext(m_pbuffer.get());
m_camera->setComputeNearFarMode(osg::Camera::DO_NOT_COMPUTE_NEAR_FAR);
m_camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
m_camera->setViewMatrix(osg::Matrix());
m_camera->setProjectionMatrix(osg::Matrix::ortho2D(0, 1.0, 0,
1.0));
m_camera->setViewport(new osg::Viewport(0, 0, 640, 480));
m_camera->setDrawBuffer(GL_FRONT);
m_camera->setReadBuffer(GL_FRONT);
m_viewer->addSlave(m_camera.get(), osg::Matrixd(),
osg::Matrixd());
m_viewer->realize();
I do not know if the same would work on Linux, as pbuffers on Linux are an
optional extension that might not be supported.
I get this to render at arbitrary frame rates, entirely decoupled from the
screen's VBLANK interval.
Christian
2016-08-18 16:47 GMT+02:00 Chris Thomas <ctho...@soasta.com>:
> Hi,
>
> OK, I based my initial integration into my app on osgteapot.cpp. As with
> all the other examples, it os run via
>
> viewer.run();
>
> And this creates an output window in OSX (and I am assuming any other OS
> its run on). And thats the issue I have, I need OSG to run "headless", that
> is to say, producing no visible window in the OS.
>
> If OSG is rendering away, to a non visible buffer, I can then expose this
> to the user via my UI api (see above). Having this visible viewer, is the
> issue right now. Is there an option to run viewer with no visible
> display/window, or is there an alternative to viewer() ?
>
> Thank you!
>
> Cheers,
> Chris
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=68420#68420
>
>
>
>
>
> _______________________________________________
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
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