Re: [osg-users] Change for need to redraw scene

[Hartmut Leister]

Hi Filip,

Am 02.12.2011 12:39, schrieb Filip Arlet:
> If you want redraw on demand
exactly.

> Code:
> 
> if( viewer->checkNeedToDoFrame() )
> {
> viewer->frame();
> }
I will try this and keep you updated.

> Btw. comparing two matrices of doubles has to be done with epsilon delta
of course, how could I forget...should have known this.

Thank you
Hartmut

-- 
Hartmut Leister 
04317 Leipzig
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Re: [osg-users] Change for need to redraw scene

[Filip Arlet]

Hi,

for redrawing, call function requestRedraw() on View(er) you want to redraw. I 
suppose you are changing the scene by yourself. 

If you want redraw on demand, other than calling frame by yourself use 
osgViewer::Viewerbase::setRunFrameScheme(ON_DEMAND);

In QtViewer example there's QTimer for redrawing, but it calls frame() every 
tick. If you want redraw on demand, see fuction osgQt::setViewer() or use this:

Code:

if( viewer->checkNeedToDoFrame() )
{
viewer->frame();
}





Btw. comparing two matrices of doubles has to be done with epsilon delta, 
because of precision problems.

Cheers,
Filip

--
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=44187#44187





___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

[osg-users] Change for need to redraw scene

[Hartmut Leister]

Hello OSG-Users,

(I'm writing a display application, using osgviewerQt)

I'm looking for a way to check, whether I need to redraw the scene to skip a 
redraw, if would be the same as the previous (fixed image). Or is this already 
done by osg-library?
I figured, I only need a redraw, if
a) Camera changes (position, field of view)
b) scene changes (geometry changes, color changes)

Unfortunately my first guesses and web searches were not successful, e.g. I 
saved the cameras ViewMatrix ( getCamera()->getViewMatrix() ) after a call of 
frame() to compare it to the current before the next call of frame(). Oddly the 
seem to change every time, even though the Viewer showed a fixed image.

Can anyone point me to a direction and offer hints, to how I can achieve this?
Am I carrying coals to Newcastle, since OSG would already be doing this and/or 
I only forgot to set a flag?

Thanks in advance and sunny greetings
Hartmut
-- 
frag nicht - du könntest eine antwort erhalten

NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!   
Jetzt informieren: http://www.gmx.net/de/go/freephone
___
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org