Farshid Lashkari wrote on Monday, November 13, 2006 1:57 PM: > Hi Zach, > > On 11/13/06, Zach Deedler <[EMAIL PROTECTED]> wrote: >> Yes, removing the shaders causes it to render just fine. Somehow, >> shaders applied to light points causes big problems. >> >> Anybody else use light points in there scenes with glsl shaders? > > It seems that enabling GL_POINT_SMOOTH with fragment shaders causes > the driver to go into software mode. I found the following pages on > the OpenGL message board that seems to verify this: > > http://www.opengl.org/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=3;t=013 811#000000 > http://www.opengl.org/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=3;t=013 508#000008 > > It seems the only workaround is to use point sprites. > > -Farshid
I don't think it's just when there are shaders; my test app (a trivially modified osgviewer loading data from my own ReaderWriter) is not using shaders, but I am seeing dramatic slowdown due to GL_POINT_SMOOTH. When I comment out the state.applyMode(GL_POINT_SMOOTH,true) calls in LightPointDrawable::drawImplementation, the problem goes away (but of course lightpoints show up as little rectangles); when I uncomment those lines, my frame rate sometimes drops from about 80 to around 10. I haven't been able to pin down the exact circumstances, but I have several reproducable test cases (unfortunately, using proprietary data so I can't distribute it). My cull times seem unaffected, but my draw times increase dramatically when the frame rate drops, and it doesn't seem to be due to extreme changes in the scene (for example, large numbers of lightpoints aren't entering or leaving view). Using point sprites also fixes the performance, but I'm not sure I want to go that direction. I'm running an ATI Radeon 9800 with OpenGL Version 6.14.10.6174 (Catalyst 6.11). OSG version is 1.2. OS is WinXP Pro. -- Bryan Thrall FlightSafety International [EMAIL PROTECTED] _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
