Fwd: Re: [vtkusers] on & offscreen render windows

Michael Bonner bonner10 at llnl.gov
Thu Sep 30 17:22:11 EDT 2004


>Date: Thu, 30 Sep 2004 09:57:35 -0700
>To: John Shalf <jshalf at lbl.gov>
>From: Michael Bonner <bonner10 at llnl.gov>
>Subject: Re: [vtkusers] on & offscreen render windows
>
>
>in my example the actors, mappers, and source that the on & off screen 
>windows have are unique instances. Everything.. i think.. is unique among 
>the two windows, except, the root window has an interactor and a vtkCommand.
>
>Im reading up on my OpenGL (so please excuse my naivete), but, renderering 
>in the middle of interaction makes a seperate context current, I dont know 
>how this would effect other contexts. Also, I have tried calling 
>vtkXOpenGLRenderWindow::Frame (which calls glxSwapBuffers, as well as 
>MakeCurrent), I have tried disabling the interactor (thinking that x event 
>handling may play a role in my problem).. in short.. I have tried many 
>things.. and I really have no idea what is causing the problem I am 
>seeing.. actually I really have no idea what the problem really is.. I am 
>just observing the symptons.
>
>Thansk for your help
>-mike
>
>
>At 06:45 PM 9/29/2004 -0700, you wrote:
>
>>VTK doesn't like it if you use the same actors for both offscreen and
>>on-screen windows.  At minimum, you need to have a separate set of
>>actors for each.  I can't remember if that is true for the mappers as
>>well, but it would not be surprising as the mappers will be using
>>display lists (caches of the OpenGL commands that can be stored on the
>>video card).  So you might need to replicate the mappers as well (can't
>>remember on that one).
>>
>>-john
>>
>>On Sep 29, 2004, at 4:39 PM, Michael Bonner wrote:
>>
>>>
>>>Hello vtk users,
>>>
>>>I am trying to use two vtkRenderWindows w/ two vtkRenderes in a single
>>>application. One of the render windows is offscreen, the other is not.
>>>  I would like to use the on screen render window for interaction, but,
>>>when a mouse key release event happens I would like the offscreen
>>>window to render.  I have included a small application that produces
>>>my problem. When the offscreen window goes to render during the key
>>>release event the onscreen window is effected.   I have not been able
>>>to diagnose my problem, everything seems to be behaving as expected,
>>>but my window, which was, prior to the offscreen render, being changed
>>>as I moved the mouse, is no longer changing. The interactor seems to
>>>still be handling events, and the render window is continuing to
>>>render, but the image on screen is not changing.
>>>
>>>My understanding of OpenGL is limited to a single undergrad intro
>>>course, and I know even less about X windows, if anybody could offer
>>>any suggestions at all I would greatly appreciate it.
>>>
>>>Thanks for your time
>>>Mike
>>>Bonner<InteractionTest.cpp>____________________________________________ ___
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