On Aug 3, 2007, at 10:47 AM, Paul Martz wrote: >> We are using SceneView from OSG 1.2 and VR Juggler in a >> multiple render thread environment. We are using the >> osgUtil::UpdateVisitor to update the graph in a serial >> portion of our code. SceneView::cull and SceneView::draw are >> called from each rendering thread. In this configuration we >> often see the displays flash the clear color on a random >> basis. We are setting the clear color through the use of a >> ClearNode and we clear the depth buffer at the beginning of >> the draw function. > > Hi Doug -- Just thinking of this in OpenGL terms, the dreaded > "blank screen" > can have many many causes. > > One possible explanation: The cull traversal on one of the displays > randomly > thinks that everything is culled. This could be due to a > configuration issue > for the camera controlling that display, the modelview/projection > matrices > are bogus and/or the view volume used during the cull traversal > isn't set > correctly. You might consider hacking the code to dump such > information out > per frame. Yes, it will generate gobs of output, but if you do a > short run > and see a flash, then examine the debug output, any one-frame > irregularities > should jump out at you. If nothing shows up, then the problem is > somewhere > else. > I will give this a shot.
> The other thought I had relates to the ClearNode. Does the problem > go away > if you eliminate the ClearNode and just let SceneView do its own > clearing? > As far as we can tell SceneView does not do clearing or not that we can find. Am I incorrect here? I have never really been able to figure out how to get reliable clearing with SceneView. Doug _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
