[vtkusers] hardware accelerated offscreen rendering without diplaying window

[Peter Schiemann]

Hello Adriano,
the patch doesn't solve the problem. It modifies vtkXOpenGLRenderWindow::CreateAWindow(), but not vtkXOpenGLRenderWindow::CreateOffScreenWindow(w,h) which is called when set to offscreen.
And I find this code in the same file:
----------------
#if defined( VTK_OPENGL_HAS_OSMESA )
  // OffScreen stuff
  OSMesaContext OffScreenContextId;
  void *OffScreenWindow;
#endif
----------------
You see that the offscreen stuff is only enabled when MESA(=software) rendering is enabled. The same "#if defined( VTK_OPENGL_HAS_OSMESA )" is repeated throughout vtkXOpenGLRenderWindow.cxx showing that offscreen stuff is not compiled when not using MESA.

Regards,
Peter


-----Ursprüngliche Nachricht-----
Von: "Adriano Gagliardi" <agagliardi at ara.co.uk>
Gesendet: Jul 26, 2011 3:03:33 PM
An: "'Peter Schiemann'" <p.schiemann70 at web.de>, vtkusers at vtk.org
Betreff: RE: [vtkusers] hardware accelerated offscreen rendering without diplaying window

>
>There is a patch that essentially comments out the lines of code that cause
>the X-window to pop up. I've been using it for a couple of years without
>issue:
>
>http://www.cmake.org/pipermail/paraview/2009-December/014908.html
>
>That should have the attachement on it (HideWindow.patch).
>
>Thanks,
>
>Adriano
>
>
>===================================
>
>Adriano Gagliardi MEng PhD
>Business Sector Leader
>Computational Aerodynamics
>Aircraft Research Association Ltd.
>Manton Lane
>Bedford
>
>Tel: 01234 32 4644
>E-mail: agagliardi at ara.co.uk
>Url: www.ara.co.uk
>-----Original Message-----
>From: vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] On Behalf
>Of Peter Schiemann
>Sent: 26 July 2011 13:47
>To: vtkusers at vtk.org
>Subject: Re: [vtkusers] hardware accelerated offscreen rendering without
>diplaying window
>
>Hello Victor,
>with VTK you only have the choice of either accelerated rendering on a
>physical display or software rendering which can be off screen. There has
>been no attempt to support pure off screen with hardware support for several
>years. As you say, the best alternative is Visit. What you need works out of
>the box.
>If you need a solution in VTK, study the class vtkXOpenGLRenderWindow.cxx
>and find out why it pops up an unnecessary window although set to offscreen.
>I was told it is not difficult, but I am not familiar with X windows
>programming.
>
>Good luck!
>Peter
>
>
>>Dear VTK gurus!
>>
>>I was wondering about the status of hardware accelerated offscreen
>rendering in VTK *without* displaying an X window on the server (linux
>operating systems).
>>
>>If this is possible, can somebody please document the CMake settings and a
>usage example in the VTK Wiki?
>>
>>There have been several discussion threads on this issue, but I found
>>no solution. They all gave up at some point. I guess
>>http://www.vtk.org/Wiki/VTK/Examples
>>/Cxx/Utilities/OffScreenRendering is the "official" example, how to render
>offscreen. But unless compiled with software rendering, it still displays an
>X window.
>>
>>If this is impossible with VTK, why?? VisIt is capable of hidden,
>accelerated offscreen rendering. SoQt can easily do it, too.
>>Is VTK designed differently, so that use of modern pbuffers or frame buffer
>objects is excluded? Then please say so, and people can make their choice.
>>
>>Thank you
>>Vic
>
>___________________________________________________________
>Schon gehört? WEB.DE hat einen genialen Phishing-Filter in die Toolbar
>eingebaut! http://produkte.web.de/go/toolbar
>_______________________________________________
>Powered by www.kitware.com
>
>Visit other Kitware open-source projects at
>http://www.kitware.com/opensource/opensource.html
>
>Please keep messages on-topic and check the VTK FAQ at:
>http://www.vtk.org/Wiki/VTK_FAQ
>
>Follow this link to subscribe/unsubscribe:
>http://www.vtk.org/mailman/listinfo/vtkusers
>
>
>**********************************************************************
>This email contains information that is private and confidential and is intended only for the addressee.
>If you are not the intended recipient please delete it and notify us immediately by e-mailing the sender.
>Note: All email sent to or from this address may be accessed by someone other than the recipient, for
>system management and security reasons.
>Aircraft Research Association Ltd. Registered in England, Registration No 503668 Registered Office:
>Manton Lane, Bedford MK41 7PF England VAT No GB 196351245
>
>**********************************************************************


___________________________________________________________
Schon gehört? WEB.DE hat einen genialen Phishing-Filter in die
Toolbar eingebaut! http://produkte.web.de/go/toolbar