H Thorsten, On Saturday, September 18, 2010 01:47:38 pm ThorstenB wrote: > Hi, >
> So, please, any help on this bug, any hints on what I could check, > which FlightGear modules could be related, any ideas on how to locate > this issue are welcome. > To the best of my knowledge, this is a (more or less) known problem. I've experienced it as well on a number of longer flights. IIRC, Curt mentioned observing this on a number of occasions as well. As far as I know, nobody has yet stepped forward to get to the bottom of it, but I did find something that serves as a stopgap when the problem does occur. Just cycle through all the views once, and you will find the missing tile appear once again. FWIW, FlightGear's scenery is loaded in tiles. The loading and unloading mechanism used to be such that scenery tiles surrounding the user's aircraft were loaded as it was flying into new areas, and existing tiles were unloaded as the aircraft was getting more and more distant from that tile's location. Currently, the tile loading mechanism is a lot more complicated, because other factors are also involved in the loading and unloading mechanism. These factors include, among others, the current viewpoint, and also height above terrain calculations. As a consequence, FlightGear's tile loading and unloading mechanism uses a highly complicated priority system that determines which tiles need to remain in memory, and which ones can go. In addition, is suspect (and I'm not 100% sure about this) that loaded tiles can either be flagged as visible, or invisible (the latter being case when loaded tiles are beyond the current visibility limit). Given, my observation that cycling through all the viewpoints, will restore the visibility of tiles that have gone lost, and flag tiles that were visible during the previous view cycle invisible, makes me suspect that something in the code that determines tile visibility may go astray after a prolonged number of tile crossings. Unfortunately, I'm not too familiar with the tile loading code to be more specific, but I hope that my observations / suggestions may be helpful in resolving this bug. Cheers, Durk ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
