Thank you for your precious advice Robert. Cheers, John On May 30, 2012, at 10:23 AM, Robert Osfield wrote:
> Hi John, > > On 30 May 2012 00:16, Gio <[email protected]> wrote: >> So... your suggestion is to optimize the 3d model reducing the number of >> vertices because face culling will not improve performance? >> Can you argue more about why is like that? > > Paul explained... if you are fill limited then back face culling can > help, if not then it make little difference. > > Fill limited is when the GPU has saturated it's ability to deliver > pixels to the frame buffer. One way to find out whether you are fill > limited or not is to change the size of the window you are rendering > to so that it's smaller, if performance goes up then you are fill > limited. > > There are many potential bottlenecks that can occur when doing > graphics, fill limit is only one of them. Paul suggestion of being > vertex limited is one of them. The way to test this is to render a > series of models with increase number of vertices by a constant fill > load and constant number of objects. You can use the osgsimplifer > example to illustrate how to cut the number of vertices down on a > model. > > As for the many other different types of bottlenecks, well there is > are simply too many to expand upon in my message, but the topic of > optimization has been covered many times on the mailing list/forum, > and plenty of books and online resources on optimization of graphics. > It's a huge topic, I'm twenty years into my exposure to computer > graphics and am still learning new things. It's a topic that you > should be prepared to invest time and energy into. > > Robert. > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
