Nodes sometimes do not show

Hello guys! (:

In my app, there are some spots where all nodes are gone! I can't see none of them. Then I change the cameras angle and change the view and all they come back! I don't know what's happening. If you guys can't understand me, I can post a video.

Thanks, hope you guys can help me.

Oh…I encountered a similar problem some time ago.

For me it sounds like invalid bounding boxes. For  what reason ever some of my boundingboxes got invalid, this way Frustum Culling could not work so the nodes disappear. They were rendered only in a special angle a.s.o.

Maybe this is a help for you.