hi Geoff , > And I understand some screen shots were posted > on the PAF forum, but still to find these... a link would > help... http://equipe-flightgear.forumactif.com/t1096p15-vol-en-formation-avec-un-fg-patche#20638 > Oh, and I always use mpserver14.flightgear.org, Switzerland, > and perhaps attempts while using the SAME fgms server may be > better... yep, that's the rule we are following during our formation flight: to be on the same mpserver. Being on different servers give more jitter and lag, and there's no way to compensate for the inter-server lag now, as we have no information about them. >> http://wiki.flightgear.org/Mp-patch > Have downloaded and am looking at your wiki lag patches > with an aim to patch my 2.11... in Windows 7 and > Ubuntu... but not sure how far I will get... good luck :) , for your information, a patched 2.11 windows binary is available and updated once a week, if you can't compile it yourself, see detail on the wiki. > > It would certainly be nice if both pilots saw the > same scene ;=)) But this is not the ONLY problem... > >> basically the mp sending rate is fine with 10 pps > Well yes if the packets flow, but many things do seem > to interrupt that flow... > > One of the biggest is F3 - take a screen shot - This > seems to stop packets for a seconds or more... i never use F3 for screenshots, as it freeze fg , instead i use the os printshot feature, much better and harmless (and it has the antialiasing from the gpu) > > Loading a new scenery tile can be another... new weather > metar, although in the victor I usually select simple > Fair weather... but there seems to be a number of things > that 'change' the packet flow... I even suspect mp > chat causes small blips... those are not change in paquet flow, but 'freeze' in FG itself, when some frame take time to render, being stuck on a model loading, or a metar change, or a F3 etc To avoid mipmap generation hang, I use dds texture for all the planes in my aircraft folder (with a script), the mipmap are not generated on the fly and the loading is faster (taking less space in ram too). that's why in the paf hangar we are providing both a .png and a .dds version of the planes. > So the aircraft pilot sees the tanker quickly move > away... accelerate and moves forward... quite > un-nerving... And this can happen even without a > heavy F3 event... perhaps even due to system thread > changes, ie nothing to do with the running fgfs... we call this the "rubber band phenomen" :D, mainly caused by jitter, and worse if we are not on the same server. > So I must take another look at this fill-in code, > and would like to hear from the person or persons > who implemented it... and understand why the very > apparent slide fast forward, and what controls how > quickly the position returns to that of the current > packets after such an artificial change... any > README, links, etc... the current code in AIMultiplayer.cxx got a prediction system, but try to nether use it. this is done to have only an interpolation between two packets to do. so we display the mp plane at least one packet late to have a margin. > And then there is how will your 'lag' correction > effect this current extrapolation code? If at all... I reused the existing code, with some modifications wich are: - very slow response to jitter: the rubber band phenomen is just a little noticeable, seen as a speed variation of the followed plane. - i'm sending and using planes's accelerations (only for yasim and jsbsim yet), so the position is predicted using position, speed and acceleration with a basic equation. If some are interested i can detail a little more this on the wiki page.
if you are using the patch, be aware that non patched yasim planes transmit a velocity in airmass instead of ecef, so they are very shaky if displayed in the futur with some wind. > Maybe later try an E-W run, since you do mention some > differences depending on direction... this is an effect of the patch with jsbsim aircraft, i needed to find an acceleration suitable, so i added one in jsbsim, but aparently this is not perfect yet, but at 10 pps, it nearly unnoticeable. I guess this should be a jsbsim expert job :) jano ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
