Hi Robert, yes one frame latency is OK. Is there an example about the PBO usage? osgscreencapture seems to be about getting the data from frame buffer not from an RTT texture.
tugkan > Hi Tugkan, > > On Thu, Jan 14, 2010 at 12:31 PM, Tugkan Calapoglu <[email protected]> wrote: >> I know that getting data back from GPU is slow but 12ms for a 4x4 >> texture seems extreme. > > It's the flushing of the fifo that is the problem, that's why it's so > slow, not the data transfer itself. Once you flush the fifo you loose > the parallelism between the CPU and GPU. > > The only way to hide this is to use PBO's to do the read back and do > the actual read back on the next frame rather than in the current > frame. In your case you might be able to get away with this, a frames > latency might not be a big issue if you can keep to a solid 60Hz and > the values you are reading back aren't changing drastically between > frames. > > Robert. > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > -- Tugkan Calapoglu ------------------------------------- VIRES Simulationstechnologie GmbH Oberaustrasse 34 83026 Rosenheim Germany phone +49.8031.463641 fax +49.8031.463645 email [email protected] internet www.vires.com ------------------------------------- Sitz der Gesellschaft: Rosenheim Handelsregister Traunstein HRB 10410 Geschaeftsfuehrer: Marius Dupuis Wunibald Karl ------------------------------------- _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
