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.
One thing you might try is clamping the gear force to that produced by fully compressed gear. That way, you avoid the absurd forces produced by springs compressed by 100x their real-world size. It doesn't fix the underground problem, but it might help keep the results from exploding. Curtis L. Olson wrote: > 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.) What YASim does is just lift the plane up until the (fully extended) gear are off the ground, and drop it. The plane bounces nicely to a stable resting orientation. One thing to consider would be exporting the tile geometry to the FDMs in some way. Assuming a flat ground plane is fine for runway environments, of course, but curved surfaces won't work that way. One way to do it would be for the FDM to provide a line description (direction of gear compression), which the scenery would convert into an intersection point and a normal vector for the ground at that point. In particular, ski jumps have curvature of the order of the inter-gear distance, and can't be approximated with any plane at all. Of course, these are very special purpose, and might best be handled with a special case inside the gear code... Andy -- Andrew J. Ross NextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com "Men go crazy in conflagrations. They only get better one by one." - Sting (misquoted) _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
