After what literally seems like yonks, I've finally worked out the solution to the problem I described several posts back, namely that the perspective was all wrong in my game Passenger - it was drawing stuff further away over the top of stuff that was closer - like this:-
Needless to say, the problem had an easy solution (once you know what it is) - a missing "updateGeometricState()" on the root node when adding an object. Arrggh!!!
Here's what it looks like now:-
A dramatic improvement I'm sure you'll agree. And now I can finally get on with improving the game rather than messing about with small bugs!