[Flightgear-devel] YASIM question (for Andy Ross)
Hi Andy, First of all, thanks for your help with the config file. Now I have another question: I would like to ask you if it is possible to start from Yasim in order to obtain a ground vehicle dynamic model. My idea is to develop a truck simulation inside FlightGear and I have thought to start from Yasim because it uses the rigidbody dynamics; moreover in this way I inherit the interface to FlightGear. But there is a little problem: the collision detection, which is not implemented. Moreover the airplanes on the gorund don't follow the slope of the terrain in a realistic manner: they go down parallel to ground if there is a heavy slope: is this behavior due to the fact that the only point of reference is the cg of the aircraft and not the position of the wheels? I would appreciate your opinion about!! Thank you in advance!! Marco ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] YASIM question (for Andy Ross)
Hi Andy, First of all, thanks for your help with the config file. Now I have another question: I would like to ask you if it is possible to start from Yasim in order to obtain a ground vehicle dynamic model. My idea is to develop a truck simulation inside FlightGear and I have thought to start from Yasim because it uses the rigidbody dynamics; moreover in this way I inherit the interface to FlightGear. But there is a little problem: the collision detection, which is not implemented. Moreover the airplanes on the gorund don't follow the slope of the terrain in a realistic manner: they go down parallel to ground if there is a heavy slope: is this behavior due to the fact that the only point of reference is the cg of the aircraft and not the position of the wheels? I would appreciate your opinion about!! Thank you in advance!! Marco ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] YASIM question (for Andy Ross)
Marco Gugel wrote: My idea is to develop a truck simulation inside FlightGear and I have thought to start from Yasim because it uses the rigidbody dynamics; Right. That's the RigidBody/Integrator/BodyEnvironment implementation. You set masses on the body, calculate forces inside the environment, and let the integrator figure out the result. But there is a little problem: the collision detection, which is not implemented. Moreover the airplanes on the gorund don't follow the slope of the terrain in a realistic manner: [...] is this behavior due to the fact that the only point of reference is the cg of the aircraft and not the position of the wheels? This is a different problem, and not the only one you are going to discover. Indeed, the collision detection is a hack right now, which presumes a horizontal ground plane under the aircraft. This works just fine for airfields, but not so well for hills (or ships/carriers, for that matter). It's not related to c.g. or positioning issues at all; in fact the application of force at the position of the wheels *is* modelled correctly in YASim, and the c.g. is computed dynamically from the mass distribution; it isn't a user visible parameter... All (heh) that is required to fix this bug is for the gear model to calculate a proper intersection with the terrain polygons instead of using a ground plane defined for the whole aircraft. A more serious problem, though, is that the current YASim gear force model works rather poorly for ground vehicles. It slips against side forces instead of holding position. See recent posts about the gear model for more notes. A few ideas have been kicked around, but all of them are kinda scary to implement. Andy ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
