Jump to content

Archived

This topic is now archived and is closed to further replies.

DMullert

A question regarding XPlane 10

Recommended Posts

Hello Gang!I am one of the "silent observers" here at the forums and have been around for over 20 years, posting from time to time. For the most part, I have been a MSFS series user for years, especially since days of SubLogic and FLY were over. I am also an ocassional user of X-Plane and have had the last 3 releases (the old XPlane, version 8, and version 9), and lookng forward to version 10. I am very encouraged by what has been shown so far by Austin for version 10 (the aircraft details, the new graphics methods and technology, we know about the wondeful flight modelling, etc...), but one things that has always turned me down a bit from X-Plane is ATC and AI traffic and I have not seen anything regarding that being discussed yet - maybe I've missed that. One of the most inmersive features of the FS series is the fact that you have traffic - real traffic around you. Stuff such as ADE, TTools, and the other payware traffic addons available make this happen in a very realistic manner. You can see the aircraft, you can hear the tower talking to them, you can get with them in the traffic pattern, etc..., and considering the shortcomings of the MSFS ATC system, it does a relatively decent job of controlling your aircraft and the others.Does anyone here in the forum know anything about how AI traffic will be incorporated into XP10 if at all? I wonder if Austin will eventually prep the ground so that at least commercial traffic addons such as MyTraffic and such could release X-Plane versions of their products.Thanks for any information.Sincerely,Dennis D. Mullert

Share this post


Link to post
Share on other sites
Does anyone here in the forum know anything about how AI traffic will be incorporated into XP10 if at all? I wonder if Austin will eventually prep the ground so that at least commercial traffic addons such as MyTraffic and such could release X-Plane versions of their products.
Dennis,ATC and AI are some of the main features coming in x-plane 10.See Austin's nuttiness
As well, the X-Plane 10 engine is DYNAMIC. I have now, for X-Plane 10, made it so that EACH FLIGHT MODEL RUNS ON IT'S OWN CPU. Here is what that means: If you have 20 processors, then you can run TWENTY AI PLANES WITH BASICALLY ZERO FRAME-RATE HIT. Crank the number of planes up to 20 in X-Plane 9 and watch what happens to the frame-rate. Try it now: Set the number of planes to 1 and look at the frame-rate. Then set it to 20 and look again. See the hit? That is because all of those flight models are running on ONE CPU, one after the other, in order. With X-Plane 10, each flight model can run on it's own CPU, all at the same time--if you have 20 CPUs, running 20 planes is no slower than running 1. Now, most of you don't have 20 CPUs, but if you have a quad-chip dual-core (per chip) Mac like I do, then that is EIGHT cores--and they can handle 20 flight models while hardly breaking a sweat. The frame-rate impact of 20 planes is small: We have eight cores splitting the work! As well, we have optimized the RAM-use of each airplane to be considerably lower. This means that there is less RAM impact to having 20 planes flying at once, making it much more feasible to have 20 planes at one time. So, X-Plane 10 will use less RAM, and give more frame-rate, than version 9 when loaded up with planes (all other settings being equal, of course). So why do I care about all these OTHER planes so much? Well, we have hired a full-time programmer JUST for the new ATC code for X-Plane 10. This new ATC will control ALL the planes in the sky, including yours, to deliver incredible ATC realism. Using pre-recorded WAV files, you will HEAR the controller giving instructions to the OTHER planes, and see them following those instructions on your TCAS and out the window. The other planes will all take-off, land, taxi, stop on the ramp, miss approaches and do touch-n-goes, all while taking commands from ATC, all of which are audible on your radio.
This is from 15 sept 2010 on the news page.http://x-plane.com/pg_news.html

Share this post


Link to post
Share on other sites

Hey Thanks for yoru quick reply!Indeed I missed this. Looks encouraging. I wonder if we're going to be able to assign the AI aircraft to routes like we do in MSFS and have entire airline fleets assigned to real world schedules like we do in MSFS. X-Plane is becoming the new standard.Thanks!Sincerely,Dennis D. Mullert

Share this post


Link to post
Share on other sites

I would hope the plugin SDK for XP10 is flexible enough so that 3rd party devs can produce their own ATC plugins.Then all the World Of AI flight plans could be integrated into XP10 (via the ATC plugin). Additionally AI aircraft could then be made to fly real world SID's and STAR's (again controlled via the ATC plugin).The possibilities are endless as long as Austin gives developers the appropriate level of control via a plugin SDK.

Share this post


Link to post
Share on other sites
Guest veeray

I would assume you could program that entire ATC plugin out of process using the current kit.

Share this post


Link to post
Share on other sites

Presumably if the SDK allows a plugin to create/destroy objects (ie AI Aircraft) and set waypoints.It's possible in FSX (to a large extent), I actually had a SimConnect program that took over control of AI Aircraft that were departing/arriving at airport (in my case i was "spotting" at VTBD). So it would vector them using the correct SID/STAR based on the active runway... Worked well except for aircraft that had landed since I had no easy way to direct them to the arrival gate (and didnt want the hassle of decoding the AFCAD to find taxi routes). But was quite nice to see sky filled with aircraft following proper departure and arrival procedures.That sort of thing should be possible in XP10, assuming the plugin SDK is flexible enough, but I don't know since never took much interest in doing in dev for XP.

Share this post


Link to post
Share on other sites

Ain't WOAI and 20 AI aircraft maximum an oxymoron?Minos

Share this post


Link to post
Share on other sites
Ain't WOAI and 20 AI aircraft maximum an oxymoron?Minos
I thing Austin uses number 20 to give an example. Where does it say that you won't be able to have more than 20 planes at once? From what I understood you will be able to have more than 20 with the respective demand on resources.Cheers

Share this post


Link to post
Share on other sites
I thing Austin uses number 20 to give an example. Where does it say that you won't be able to have more than 20 planes at once? From what I understood you will be able to have more than 20 with the respective demand on resources.Cheers
I thought I read in one of the posts or forums that at release, you will be limited to 20, with more in an update later on. This would be mainly because with each having their own flight model, very few computers could handle any more that 20. I could be completely wrong though.personally, I am wondering how my computer will handle it, because it has many cores (8 with hyperthreading) but a low clock speed (1.6ghz).

Share this post


Link to post
Share on other sites

If the XP limit is 20 AI planes then a ATC plug-in needs to be able to simulate/track the progress of 1000's of aircraft itself but only create in XP the 20 closest AI aircraft to the users aircraft. And likewise destroy AI aircraft when they venture too far from the users aircraft to make room for new closer aircraft.20 aircraft seems OK to fill the sky near the users aircraft with "modest" traffic. But on the ground at a busy airport its not going to be enough.Not sure why AI aircraft need to have full flight models. Guess they will look realistic during flight.What a shame the limit is 20. IMHO very "wacky" design decision by Austin because people want max FPS and noone is going to want to run many (if any) AI aircraft with full flight models that tap FPS.

Share this post


Link to post
Share on other sites
Guest veeray

Hmm I think you'd be hardpressed to find 20 AI models that would be suitable for a given airport. Correct me if I'm wrong but I recall that being the situation with the CSL. If there is 20 then I'd guess they are full blown models and repaints.. not low detail AI objects.

Share this post


Link to post
Share on other sites
Hmm I think you'd be hardpressed to find 20 AI models that would be suitable for a given airport. Correct me if I'm wrong but I recall that being the situation with the CSL. If there is 20 then I'd guess they are full blown models and repaints.. not low detail AI objects.
Yes... which is why XP10 needs a basic (table driven?) flight model that can be used for AI aircraft. Then all the AI need to be are low poly visual models like with WOAI for FSX. Frankly with Austin's full flight model approach for AI aircraft I can't see XP10 AI being anything more than a novelty which people quickly turn off.And as we all know Austin is "always right" so the chances of it being changed are minimal. XP10 loses points here against FSX (and presumably Flight). If he wants to win more FSX converts he needs to cater for the AI crowd that demand real world flight schedules and airports/skies filled with realistic amounts of air/ground traffic.It's a great opportunity that XP10 has lost.

Share this post


Link to post
Share on other sites
Guest veeray

Quite frankly there could be nothing better than 20AI/Multiplayers with full physics.... someone in a c172 should face the consquences of taking off immediately after a b52. And besides XP9 already supports dumbed down physics can't see him removing it. My guess no one has asked for more than 16 to begin with, so 20 AI with full physics is hardly a comprimise.

Share this post


Link to post
Share on other sites
Quite frankly there could be nothing better than 20AI/Multiplayers with full physics.... someone in a c172 should face the consquences of taking off immediately after a b52. And besides XP9 already supports dumbed down physics can't see him removing it. My guess no one has asked for more than 16 to begin with, so 20 AI with full physics is hardly a comprimise.
Yes good for multiplayer, and maybe the nearest X number of planes (user option) can be full flight models. But the rest of aircraft should be low detail flight model.That way you could still have 100's of AI aircraft populating skies/ground around you but only the nearest X aircraft are using full flight model.Seems best of both worlds!

Share this post


Link to post
Share on other sites

Hey Gang!So, maybe I'm missing a point here, but why care so much about the flight characteristics of the AI aircraft around me? I could care less!!!!! As long as the AI world is there around me and I can see them, my TCAS can see them, ATC directs them, and they follow the ATC commands and SID/STAR rules, etc... I really could care less how they fly. I would definitely like to see an AI world like we have in MSFS with some additional intelligence about ATC and how the AI fly in the differnet classes of airspaces while taking into account things such as terrain around the airport and such. Maybe going this route may help save some processor real estate and power to run XP10????Please excuse my ignorance if I have missed a point here.Thanks!Dennis D. Mullert

Share this post


Link to post
Share on other sites
maybe I'm missing a point here, but why care so much about the flight characteristics of the AI aircraft around me? I could care less!!!!! As long as the AI world is there around me and I can see them, my TCAS can see them, ATC directs them, and they follow the ATC commands and SID/STAR rules,
I think its Austin that's missing the point. Seem's like he couldn't care less about having AI like in FSX and hence the 20 aircraft limit. Big mistake IMHO. If he added the ability for 100's of aircraft with simple flight models and then a sliding scale of max 20 full flight model AI/MP aircraft (the 20 nearest your aircraft) then we could have the best of both worlds!With regard to SID/STARS and complex ATC I think that's going to be the realm of 3rd party developers using the plugin SDK. Think of RADAR CONTACT but for XP10 where by it completely replaces the default XP10 ATC with a sophisticated ATC simulation including directing AI aircraft to use SIDs/STARs. Amazing!If XP10 has a flexible enough plugin SDK then this should be possible, assuming the ridiculous 20 aircraft limit is complimented with a "simple flight model" system for 100's of AI aircraft as described above.

Share this post


Link to post
Share on other sites

Hi Guys,I will have to write a blog post to go into this in more detail later, but I think a lot of what has been written here is wrong. Y'all started under the assumptions that:1. The flight model is going to be too expensive to run on AI planes and2. A table based flight model would be faster.Those are both questionable assumptions at best...pretty much everything you can conclude from that is, IMO, dubious.(I should mention at this point that I am unaware of _any_ "dumbing down" features in the FM right now. My understanding is that we will pre-process control inputs in a number of ways, and the frequency of the FM can be set to multiples of the framerate, but even at the lowest setting, we do a full physics integration and the plane is the sum of the physics that are applied to it. I mention this now because I am about to speculate on some optimizations that _could_ dumb down the physics model, and I want to make clear that shipping X-Plane 9 does not do this!!)Here's the short version:The most expensive part of the flight model is ground interaction - that is, the flight model doing collision checking with the ground and various parts of the airplane. When an airplane is "clearly in the air" (e.g. an initial test shows it has high altitude) the FM isn't very expensive; when it is near the ground, CPU time cranks up as we make sure to get the touch-down characteristics just right; same with taxiing.So if we want to make the FM faster, there's really only one place to attack: ground interactions - it's the lions share of CPU time. There are a number of simple things we could do to improve ground interaction. For example, we could stop checking for body scrapes - since X-Plane has to handle physics correctly even if the user lands gear up and scrapes an engine, the sim normally tests the full geometry of the plane against the ground (which is not flat, even at an airport) - that adds up. If we are willing to trust that the AI planes don't screw up a landing* we could cut down ground check to only real landing gear, which would improve performance.Now what if we did some kind of 'lo-fi' AI, whether it's table based or it simply says "move the plane forward by this much" (E.g. a sort of track-based system)? If we want the airplanes to 'sit' properly on the non-flat airport surfaces, we _still_ need to do the most expensive part of the FM - the wheel-ground collision checks. So the total savings of a 'lo-fi' AI flight model would be very small, because at best we might partly improve the performance of code that doesn't have much impact on the sim.(To understand why you can only boost performance by attacking the biggest pigs, see here: http://hacksoflife.blogspot.com/2010/11/is-1-lot.html for gory details.)However, there would be a pretty huge cost to a lo-fi flight model: we would have to code a SECOND implementation of pretty much everything we already do in the real flight model! We would have to have new flight model files to support this new alternate flight model. The opportunity cost here is in developer time...the time spent building a separate flight model could have been spent performance-tuning the real flight model...even if we had a second flight model, performance tuning time would now be divided between the two flight models, and neither would reach its optimal performance.Besides my explanation above of why a lo-fi flight model wouldn't really be a win, two more comments:In software development, it often pays to try the simplest thing first, see how it works, and go from there, rather than _speculate_ how a system may perform and write a ton of code up front before you have real data. This is what we are doing...the simplest thing we can do is to run the real FM on the AI planes, and so far it looks like it's going to work reasonably. IF we hit data that says "no we have to do something radical", then we will...when the data says so, and no sooner. So far indications are that the real FM is going to be fine, and this makes sense from what we know about its performance characteristics. We also know that we have a lot of tricks we could pull to make the real FM faster for AI planes (e.g. removing engine scrape-checks, per above) before we have to go and write a whole new FM.And finally, dude, the real FM _looks good_. With the real FM, the AI planes move the way big heavy airplanes should move. They track the ground perfectly. If the ground has a bump and the airplane's suspension is loose, it sways like it should. The control surfaces deploy with their real time. When you're at an airport performing ground ops, you can get really close to the AI planes, and at that point these things matter! I speculate: once you take follow an AI plane running the real FM on the ground, it'll be hard to go back to a 'synthetic' FM.cheersBen* This may not be a safe assumption...what if a microburst hits an AI plane?

Share this post


Link to post
Share on other sites

Yes real FM sounds great BUT... in practice how many AI planes is that going to allow?Lets assume that the plug-in SDK is flexible enough to allow a 3rd party dev to create a realistic ATC/AI simulation comprising:-1) Turn off the default XP10 ATC2) Implement realistic ground, clearance, departure, arrival, enroute ATC (think RADAR CONTACT for FS9)3) Implement real world flight schedules using the World Of AI (WOAI) schedules (controlled by the plug-in) and AI models (converted to XP format)4) Implement SID/STARs (ie AI aircraft actually follow correct departure/arrival procedures)Now imagine your at any big international airport, EGLL, YSSS, KJFK, WSSS etc. You going to see dozens of aircraft on the ground waiting at gates, about 10 aircraft taxiing in or out, maybe 1 or 2 actually on their takeoff or landing rolls, and probably another 30 aircraft within a 50nm radius flying the appropriate SID or STAR based on active runway.All this activity is being tracked/controlled by the 3rd party plug-in. It's setting way-points (lat/lon/alt/spd/rate of climb/decent) for the AI planes and letting XP10 actually 'fly' the aircraft appropriately using the flight model. BUT if XP10 only lets a max of 20 aircraft then the whole scenario described above wont work, instead every international airport will be almost dead!You've probably never seen or used FSX loaded fully with WOAI at a big airport, the immersion created by all the activity is outstanding. For XP10 to never be able to accomplish the same thing due to the 20 aircraft limit is a great loss of potential.Isn't there someway you can up the limit to say 200 aircraft whilst still maintaining high fps? Giving nearby aircraft a "hi-fi" flight model (ie this is what the user will see) and aircraft that are further away a very low-fps flight model. With aircraft far away its basically only the nav lights (especially at dusk/night) and TCAS "shadow" that are visible, so no ones going to actually notice the "lo-fi" flight model.edit: Of course you could let the user specify the ratio of 'hi-fi' to 'lo-fi' FM for AI aircraft, so they can scale as hardware permits.edit2: Understand what you say about not wanting 2 implementations of the FM but for XP to support say 200 aircraft then something has to give? But I guess what you're saying is NO there will never be any more than 20 AI aircraft, which is why you insist that a "lo-fi" model is not needed. Hypothetically if XP10 was to support 200 AI aircraft then surely you would have to consider some "lo-fi" model. When I say "lo-fi" maybe its still the same FM code as the "hi-fi" model but with various compute expensive bits turned off. Maybe you only do ground collision detection every 10 frames instead of every single frame? Tweaks like that to make it "lo-fi" and thus support 200 AI aircraft.edit3: Also, surely AI aircraft sitting stationary at the gate would have their FM turned off? So a busy airport populated with 100 parked aircraft is not consuming any FPS due to FM calcs. Can't you entertain the idea of more than 20 aircraft? You guys are really smart/experienced and surely you can work out a solution that lets XP10 have hi-fi flight model where it counts and still have 200 AI aircraft... IMHO you should be trying to make XP10 raise the bar and far exceed whats possible in FSX/Flight.

Share this post


Link to post
Share on other sites
edit2: Understand what you say about not wanting 2 implementations of the FM but for XP to support say 200 aircraft then something has to give? But I guess what you're saying is NO there will never be any more than 20 AI aircraft, which is why you insist that a "lo-fi" model is not needed. Hypothetically if XP10 was to support 200 AI aircraft then surely you would have to consider some "lo-fi" model. When I say "lo-fi" maybe its still the same FM code as the "hi-fi" model but with various compute expensive bits turned off. Maybe you only do ground collision detection every 10 frames instead of every single frame? Tweaks like that to make it "lo-fi" and thus support 200 AI aircraft.
That is not at all what I am saying. I will comment on 20 airplanes tomorrow in a blog post, I don't have time to write it up right now.My point was only that:- we don't need to invent a second flight model.- using the real flight model doesn't mean we can't optimize./ben

Share this post


Link to post
Share on other sites
Guest veeray

Ben: Also I don't think MS uses tables to begin with for ATC/AI aircraft... like you mentioned it seems to be tracked/rails and I believe that's because the ATC system only has control over the 6 variables plus groundspeed.

Share this post


Link to post
Share on other sites

Personally I'd rather have the full flight model system with optimisations and grow the number of aircraft over time than something like MSFS handling.That said, It's probably better to actually see it implemented instead of guessing what it will look like.

Share this post


Link to post
Share on other sites

I never understood the fascination some people have with AI planes. For me it's the thing I immediately turn of to get a better frame rate in FS9 and FS-X.As some have commented the FS AI looks like its on rials and on close inspection the AI planes do strange things. For the few times I need a crowded sky I would like an AI system that hooks into the real world flight tracking flight radar systems like this site http://www.flightradar24.com Maybe its even better to have a dedicated service log all that info so you can pick a date and time and have perfect AI traffic all the time. (some generated GA traffic would be needed but most AI fans seem to like the heavies anyway)

Share this post


Link to post
Share on other sites

×
×
  • Create New...