737NG tries XP12 :-)

[GoranM 3,793]

1 hour ago, Rimshot said:

Even X-Plane FM is generic

Not true. It’s highly customisable. To the point aircraft manufacturers are using it as a test bed for experimental aircraft that haven't even been flown.

Example.  This was fully designed, created and tested in X-Plane.  And it wasn't the first.  There is nothing "generic" about X-Plane's flight model.  To the level of actually designing prop airfoils based on real world stats and figures.

 

Edited July 21, 2023 by GoranM

[jarmstro 2,405]

7 hours ago, blingthinger said:

How we've arrived at the point of being able to shamelessly post full product reviews that have zero connection to XP in an XP forum, is a different story.

Sorry, but I thought this purpose of this thread was to compare the flight models of the two sims as reported by 737driver? As such, I thought the video was relevant.
 

[jcomm 5,996]

@Rimshot described pretty much the situation with A2A.

I think they never approached XP because they had their market well established in FSX, P3D and now, for sure, MFS.

XP gives it's users a better feel of flight overall. We feel more "at home" when simulating flight on most aircraft in XP than in MFS, specially some types that XP does really much better than MFS, like rotaries. That's how I see & feel it, and that's why from time to time I load XP to fly the Toliss or the X-Aviation MU2 now also available for XP12, or simply one of the default GA / helicopters.... But when it comes to detail XP can fail as miserably as MS FS and derivates, plus the CFD approach used by MFS.

The best devs have to use "Magic" to bring their creations closer to real world numbers, use wings / airfoils / fuselages and hidden objects that have no correspondence with the real aircraft. XP does indeed approach flight simulation, from the ground to the air, in a different way from MS FS / P3D / MFS, but, it has a core, and developers have no access to fine tuning stuff when it comes down to what that core calculates.

Same applies to weather and some aspects of scenery.

So, XP is no different from MS FS and derivates when it comes to precision / by the numbers in the creation of a detailed representation of a rw aircraft.

Flyinside sells their helis for XP too, and they use their external FM because they find it best suited for the exact representation of some of the characteristics of the helis they model. 

I've heard that DCS's FM is in it's structure rather "basic" even if complex to deal with for the programmers who have to use it, but it comes to those developers to build their own layer of abstraction for some of the aerodynamic properties of the modelled aircraft, fixed or rotaries. 

A2A has built, specially starting with ACCUSIM, their own flight and overall physics model, applying to aerodynamics and propulsion, etc... They could surely bring it to XP, but the size of the market wouldn't compensate their investment, specially now that they debuted with huge success in MFS 2020.

Edited July 21, 2023 by jcomm

[GoranM 3,793]

So much to unpack.

4 minutes ago, jcomm said:

I think they never approached XP because they had their market well established in FSX, P3D and now, for sure, MFS.

100%

4 minutes ago, jcomm said:

But when it comes to detail XP can fail as miserably as MS FS and derivates

Not really.  It comes down to what the dev knows or doesn't know.  X-Plane can "fill in the blanks" with generic values based on information already entered, if those blanks are not filled in by the dev.  In most cases, it does an ok job.  

6 minutes ago, jcomm said:

The best devs have to use "Magic" to bring their creations closer to real world numbers, use wings / airfoils / fuselages and hidden objects that have no correspondence with the real aircraft.

I have to disagree here.  Hacks are sometimes used.  Hidden objects are used for more friction.  Most of the time, these are used because friction coefficients are not known.  Friction coefficients can be used on every part of a flight model object.  

Ive seen wheels attached to wing tips, purely so the wing doesn't dip below ground level.  Adding a wheel gives a good wing/ground contact effect.  There is always a setting in planemaker that gives the correct effect, as opposed to using some kind of hack.

11 minutes ago, jcomm said:

So, XP is no different from MS FS and derivates when it comes to precision / by the numbers in the creation of a detailed representation of a rw aircraft.

Genuine question.  Does MSFS have something equivalent to airfoil maker?  I'm sure you've seen it.  From what I can tell, it doesn't have anything that even resembles the complexity of airfoil maker.  But I will gladly admit I am mistaken if it does.

 

[Rimshot 1,164]

34 minutes ago, GoranM said:

Not true. It’s highly customisable

Yes, I'm aware. 'Generic' is a indeed wrong choice of word. What I was trying to say is I don't believe A2A could rely solely on the XP FM. I'm not a developer, so I may be totally wrong, but I think with Accusim there is to much going on under the hood.

12 minutes ago, jcomm said:

The best devs have to use "Magic" to bring their creations closer to real world numbers, use wings / airfoils / fuselages and hidden objects that have no correspondence with the real aircraft. XP does indeed approach flight simulation, from the ground to the air, in a different way from MS FS / P3D / MFS, but, it has a core, and developers have no access to fine tuning stuff when it comes down to what that core calculates

And then this ^^ which would mean A2A still would have to rely on their own tech to get the aircraft behave correctly right?

 

[GoranM 3,793]

Just now, Rimshot said:

What I was trying to say is I don't believe A2A could rely solely on the XP FM.

I promise you, they could.  They certainly don't have to.  But I've seen what Planemaker and airfoil maker can do.  It's almost like saying, "Either I kill a bug with bug spray, or my shoe."

The same result, using different methods.  

2 minutes ago, Rimshot said:

And then this ^^ which would mean A2A still would have to rely on their own tech to get the aircraft behave correctly right?

I will say that Laminar have opened up the SDK to some areas of the flight model that can be fine tuned, as well as making the acf file (the file that determines flight model characteristics) as an editable text file.  But in my eyes, these details would be completely unnoticeable to all but the most astute aircraft engineers.

[jcomm 5,996]

7 minutes ago, GoranM said:

 

Genuine question.  Does MSFS have something equivalent to airfoil maker?  I'm sure you've seen it.  From what I can tell, it doesn't have anything that even resembles the complexity of airfoil maker.  But I will gladly admit I am mistaken if it does.

 

Not even by far.

MFS 2020 FM is no reference for XP, quite on the contrary - they tried to get as close as possible, but didn't succeed... I was referring to external approaches like those followed by A2A.

And indeed in some aspects XP is highly open to some specificities, like a recent approach taken in modelling negative flap aerodynamics for a PIK 20 glider, using a data structure that was available probably since the times of XP9 (?).

 

[mSparks 2,094]

there is a lot, lot more to the physics simulation than "just" the aircraft flight model.

There is also the interaction with the ground/ground handling, turbulence implementation, general weather simulation e.g. wind layers, storms, ground effect, interaction with the airport elements (e.g. jetways) pushback... and the list goes on.

All of which are lost/need to be recreated/synchronised if you move to an external physics engine.

[Krakin 5,841]

7 hours ago, GoranM said:

no X-Plane add on has ever had to use some kind of external flight model to make an aircraft fly correctly.  

Not even the Flyinside helicopters @jcommmentioned? I noticed you didn't address that...

[mSparks 2,094]

1 hour ago, Krakin said:

Not even the Flyinside helicopters @jcommmentioned? I noticed you didn't address that...

https://flyinside-helis.com/home-47

Quote

FLIGHT DYNAMICS

This is not a hack! The FlyInside B-47-G2 integrates a custom flight model. We also bring the same high-fidelity flight model to X-Plane via a custom plugin.

Initially developed for FlyInside Flight Simulator, our flight model provides an authentic helicopter flight experience, with realistic collective/cyclic response, ground effect, flap-back, transverse flow, torque/yaw, VRS, auto-rotation capabilities, and more!

So they were happy with their physics engine for those specific aircraft, not so happy with the visualisation/hardware suppot, so "exported" it to MS and XP.

This is very much the purpose of the CIGI/HLA/DIS etc standards at the commercial level. Its not that they "had to" build their own, it's that they did, and "plugging" that in to other software is way less investment than starting everything from scratch, less cost, better outcome = more profit.

The "gods" there is still very much unigine

https://unigine.com/products/sim/use-cases/#simulation-and-training

But they have virtually zero interest in supporting the consumer market. They pride themselves in having 250 customers.

Outstanding helicopter physics support in XP/Planemaker is a relatively recent development (circa XP11.30/Jan 2019 with many further improvements afterwards)

 

Edited July 21, 2023 by mSparks

[GoranM 3,793]

1 hour ago, Krakin said:

Not even the Flyinside helicopters @jcommmentioned? I noticed you didn't address that...

I haven't heard of him/them.

I already did mention that the SDK has been opened up to further customization, and that the acf is now editable via any text editor.  Please check the last line in this post.

Do they HAVE to customize the flight model?  No.  Did they?  According to them, yes.  To what extent?  I have no idea.  If it's a completely external flight model, independent of X-Plane, then I have to ask "Why??"

There is, literally, no need to have a completely external flight model.  There are other, very high fidelity helo flight models, using the core X-Plane flight model, and they operate beautifully.  Dreamfoil is one that comes to mind.

X-Plane has always been known for having a very high quality helicopter flight model.  Because of this, personally, I don't think they needed further customization. 

1 example out of several hundred add ons, is not really something that would sway me into thinking the X-Plane flight model is faulty.

 

Edited July 21, 2023 by GoranM

[jarmstro 2,405]

49 minutes ago, GoranM said:

I haven't heard of him/them.

I already did mention that the SDK has been opened up to further customization, and that the acf is now editable via any text editor.  Please check the last line in this post.

Do they HAVE to customize the flight model?  No.  Did they?  According to them, yes.  To what extent?  I have no idea.  If it's a completely external flight model, independent of X-Plane, then I have to ask "Why??"

There is, literally, no need to have a completely external flight model.  There are other, very high fidelity helo flight models, using the core X-Plane flight model, and they operate beautifully.  Dreamfoil is one that comes to mind.

X-Plane has always been known for having a very high quality helicopter flight model.  Because of this, personally, I don't think they needed further customization. 

1 example out of several hundred add ons, is not really something that would sway me into thinking the X-Plane flight model is faulty.

 

Is there a downside to using an external flight model? Would I be right in thinking that one advantage might be better fps?

[blingthinger 649]

7 hours ago, Rimshot said:

'Generic' is a indeed wrong choice of word. What I was trying to say is I don't believe A2A could rely solely on the XP FM.

Actually, I kind of think generic is an OK word to use here. Generic meaning that you can model most any airframe with a high degree of fidelity because it's a fully predictive (to use a Murmur description) model, and all based on the same governing equations and configuration options. Compared to a replay-only model like the FSX/Asobo methods.

I don't consider the hidden wings and even wheels-on-wings to be cheating per se. I remember jcomm mentioned that past aerobatic model using hidden rockets to get some of the maneuvers down. I count that as cheating and it isn't necessary anymore either. But additional aero surfaces...not so much. XP calculates the lift and drag forces on those surfaces in the same way as the main wings and they were most certainly there to augment the fuselage model, which is actually XP's weak point.

Wheels-on-wing-tips is done because someone had to increase or decrease the wingspan slightly to get a lift/drag target. Guaranteed it wasn't doubling the wingspan. Probably changed it by a foot or 2 from the IRL value. %change of the whole wingspan is probably small there. Not a huge deal. It's still a model.

A2A focuses on fairly generic airframes. Maybe the most 'exotic' being the v-tail of the V35 Bonanza or the Connie. XP can inherently simulate either empennage without any tricks or hidden rockets. Certainly they could decide to use XP's special force-addition drefs, but I do doubt that they'd conclude it would be needed. I also don't fault their decision to not go there at all. It's a very different design paradigm and they're fairly set in their path with great success.

Edited July 21, 2023 by blingthinger

[jcomm 5,996]

FlyInside B-47G for X-Plane The FlyInside B-47G Helicopter for X-Plane. Enjoy the realistic flight model, detailed artwork, and authentic systems

 

Bell 47G-2A1-FlyInside-B47G (x-plane.org)

 

But!  After having finally downloaded a manual for the Bell 47 - XP11 - I'm really not sure anymore if in X-Plane FlyInside runs the FM outside of XP ???

The "Store page" above doesn't have any specific info on this either.

I just created a post asking at their support forum at the .Org : Flyinside Bell 47 G flight dynamics - external to XP or using XP's FM ? - FlyInside Inc - Bell 47G 2A1 - X-Plane.Org Forum

Edited July 21, 2023 by jcomm

[GoranM 3,793]

1 minute ago, jarmstro said:

Is there a downside to using an external flight model? Would I be right in thinking that one advantage might be better fps?

Yes and no.  Do the pro's outweigh the cons?  More code comes at a cost in the form of CPU cycles.  Efficient code can minimize the hit on FPS, but there will be a hit on FPS.  Inefficient code can obliterate FPS.  Bad memory management can cause even more problems.

I'm not saying what they did was "wrong", and obviously it worked for them.  I'm just confused at why do something, that in my opinion, isn't really necessary for a consumer level flight sim, when the tools are already provided...unless they want to really nail down some pesky problem.  However, from what I can see, they've customized the flight model quite a lot.  

There is a lot of customization possible in Planemaker.  I'm not talking about bits and pieces here and there.  I'm talking about just about everything can be customized within Planemaker.  Maybe it's easier for a dev to code something rather than making it work in Planemaker.  Ben Supnik once told us, if X-Plane doesn't have it, code it.

Again, there are other helo's from various developers, including the default eVTOL, which was made for United Therapeutic, with the default XP flight model.  And it flies pretty nicely.  It's not a helo, but it's the same principal.  

To me, coding a completely external flight model, or even coding a large portion of the flight model, is extra work that doesn't need to be done.  But I'm sure they had their reasons.