Re: [osg-users] CullVisitor locks up on NaN matrix

I'm not aware of any reason why 0.9.8 should be "senstive" to NaN's where
0.9.6 wasn't, it might simply by an issue that compiler has optimized the
code in a slightly different way with the two code basis and the a subtle
difference is enough to trip over in a CPU or compiler bug. Have you tried
disabling optimization in the release build?

On Tuesday 25 January 2005 19:22, Jason Daly wrote:
> Hi all,
>
> An upgrade from 0.9.6-2 to 0.9.8-2 has revealed a latent problem in my
> application. Apparently, in certain cases my app would set the matrix
> in a MatrixTransform node to an invalid matrix (specifically, a matrix
> with the first 3 rows containing NaN). In version 0.9.6-2, this problem
> went unnoticed because it was happening to a very small object that took
> up a very small subgraph of the scene, so visually it would just
> disappear. However, when I switched to 0.9.8-2, the cull traversal
> started locking up and never returning. When I compiled 0.9.8 in debug
> mode, it no longer locked up on the bad matrix, and essentially behaved
> like 0.9.6 again.
>
> Now, I've been able to trace and fix the problem in my app, and I
> realize that the problem did not originate with OSG. However, I just
> wanted to bring it up in case there was any desire to examine why
> version 0.9.6 seemed more robust in this regard than 0.9.8.
>
> Here is a stack trace that (hopefully) shows roughly where it was
> getting stuck. I Ctrl-\'d the app when it locked up on several
> different runs, and the stack trace was always the same. My system is a
> Dell 530 with dual 1.5 GHz Xeons and a GeForce FX 5600 running Fedora
> Core 3.
>
>
> (gdb) where
> #0 0x00e4ec24 in osg::CullStack::pushCullingSet ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #1 0x00e4fb99 in osg::CullStack::pushModelViewMatrix ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #2 0x00b42a01 in osgUtil::CullVisitor::apply ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #3 0x00e9c3dd in osg::MatrixTransform::accept ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #4 0x00e85bfe in osg::Group::traverse ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #5 0x00b3de69 in osgUtil::CullVisitor::apply ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #6 0x00e86b79 in osg::Group::accept ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #7 0x00e85bfe in osg::Group::traverse ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #8 0x00b3de69 in osgUtil::CullVisitor::apply ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #9 0x00e86b79 in osg::Group::accept ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #10 0x00e85bfe in osg::Group::traverse ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #11 0x00b3de69 in osgUtil::CullVisitor::apply ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #12 0x00e86b79 in osg::Group::accept ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #13 0x00e85bfe in osg::Group::traverse ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #14 0x00b3de69 in osgUtil::CullVisitor::apply ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #15 0x00e86b79 in osg::Group::accept ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #16 0x00e85bfe in osg::Group::traverse ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #17 0x00b3de69 in osgUtil::CullVisitor::apply ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #18 0x00e86b79 in osg::Group::accept ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosg.so
> #19 0x00b7deb0 in osgUtil::SceneView::cullStage ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
> #20 0x00b7a922 in osgUtil::SceneView::cull ()
> from /ist/projects/nve/tools/OpenSceneGraph-0.9.8-2/lib/libosgUtil.so
>
>
> I took a glance at the functions involved, but I couldn't really see
> where it could be getting stuck. If there's anything else I can do to
> help, let me know.

_______________________________________________
osg-users mailing list
osg-users@openscenegraph.net
http://openscenegraph.net/mailman/listinfo/osg-users
http://www.openscenegraph.org/
Received on Tue Jan 25 12:02:39 2005