Tony Peden writes: > Just for the record, what's most likely happening here is that since > JSBSim senses that the gear are underground on the first update(), the > gear code calculate a reaction force based on how far underground they > are. That reaction force pushes the aircraft up, often times gaining > enough momentum in the process to leave the ground. Then the result is > pretty predictable, the aircraft experiences an accident. (it will > almost certainly involve a complete hull loss, therefore it's an > accident) > > AFAIK, There are currently no limits on how far the gear can be > compressed, so the reaction forces can get very large.
The flightgear side really only knows the current ground elevation for a specific lon/lat. FlightGear has no way to know the dimensions of a specific aircraft or the relative placement of the gear. It would seem like the best thing FlightGear can do is provide the elevation of the ground for the starting lon/lat, and then it should be up to the FDM to do the rest. The FDM passes back the location of the aircraft's CG, and this combined with knowledge of the aircraft orientation and pilot view offset relative to the CG allows FlightGear to properly render the scene. I don't know the details of how it works know, but it seems like the FDM would need to find a suitable starting point for the CG given the information FlightGear can provide (which is the ground elevation.) This is a tricky area though so if there's something I'm missing feel free to point it out. :-) Curt. -- Curtis Olson IVLab / HumanFIRST Program FlightGear Project Twin Cities [EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
