On 2/22/2022 at 5:45 PM, abrams_tank said:

There is zero tweaking by the 3rd party developer on the plane’s flight model if this holy grail of a flight simulator is attained.

Speaking of holy grail this is pretty cool:  https://forums.x-plane.org/index.php?/forums/topic/262336-x-plane-12-flight-model-update-–-supersonic-transition-delta-wings-and-mass-properties/

I'm "Xplane-curious" as it were but am definitely staying tuned to XP-12.  I'm not sure how it can compete because by the time XP-12 does release MSFS will have advanced farther still and in different ways.  

Sorry if this has been asked already; will the new CFD changes automatically apply to all planes in the sim, or will they only apply to specific planes that Asobo or third party developers update?

10 hours ago, March Hare said:

They didn't ignore Robert at all. All the while he was claiming that, his self-contradictions were clear to me, as he was also saying things that made it clear they were talking to him, he just refused to accept their responses. They were in constant contact, but he kept insisting to them that there was something fundamentally wrong with their underlying code, halting his progress, which it turned out there wasn't, and so progress resumed once they finally got on the same page.

This is factually incorrect in every sentence! Asobo have never contact me or responded except for one standard acknowledgement that they received one email in the first two weeks of release. No-one on any development team has ever been in touch or discussed any of the contents  of my email. I never said the "underlying code" was wrong. I said that the code purporting to be something radically different was in fact broadly a cut down version of FSX code with many parameters stripped out, and presented in text form throughout, and also said that most of the standard aircraft did not fly properly. Last year I co-signed a petition to un-encrypt the premium aircraft configuration files as the encryption prevented anyone from making minor tweaks to the flight model, even for private purposes.

Later I co-signed a developers' joint submission politely requesting more dialogue and input from a group of very experienced developers who unanimously felt the aerodynamics and special effects that influenced flight behaviour were going in the wrong direction. As far as I know a reply or acknowledgement was not received. There has been no "constant" contact. As far as a two way discussion is concerned there has been zero contact.

For what it is worth, some standard aircraft fly reasonably well, but most are devoid of harmonised controls or anywhere near accurate power settings. That wouldn't be so bad except that apart from the standard edition aircraft, the rest are all encrypted and largely un-moddable, including every aircraft sold through MSFS marketplace. There is no logical reasoning behind the encryption which it is claimed protects 3rd party copyright but in fact developers I have been in touch with never requested encryption of their config files.

Edited February 27, 20224 yr by robert young

42 minutes ago, robert young said:

This is factually incorrect in every sentence!

He might have you mixed up with Randazzo.

3 hours ago, robert young said:

I said that the code purporting to be something radically different was in fact broadly a cut down version of FSX code with many parameters stripped out

I try to understand, what you mean by that.

How is this a cut down version of this?

It is clear, that MSFS tries to accomplish realistic flight characteristics in a much more comprehensive way. The 100% scripted behaviour of FSX is basically uncompatible with the flight physics as implemented in MSFS. So a lot of FSX parameters are of no use anymore for MSFS. MSFS is a paradigm shift and devs need to adapt. The endless parameter tweaking is gone. Randazzo is saying, that in MSFS he is able to implement certain flight handling characteristics as he was not able before.

Also, to be a bit more precise, if you follow e.g. this procedure, in what way would the result be underwhelming? Be very speciifc and precise please.

Because saying the following made not much sense to me:

3 hours ago, robert young said:

For what it is worth, some standard aircraft fly reasonably well, but most are devoid of harmonised controls or anywhere near accurate power settings

What do you mean with harmonised controls? Control harmonization is defined as:

- The relationship of forces between aileron, elevator and rudder (1:2:4)
- Control forces increase steadily with deflection
- Control forces should be prohibitive for excessive control inputs
- Control forces increase steadily with aircraft speed
- Control forces should never negative

Within the limits of typical flight simulator flight control devices the sim can only do very little to influence these forces. So I wonder what control harmonization issues you have spotted in these aircraft?

3 hours ago, Krakin said:

He might have you mixed up with Randazzo.

That one literally made me spill my tea laughing.

@mrueedi, Robert will surely answer much better than me, but most of what ou link above could easily apply to fs9 / fsx aerodynamics model, the difference being that the core formulas weren't published in the documentation simply because they don't have to actually, unless ( IMO ) you wnat to use it as a "sign of deep detail" .... (*)

If you look at the documentation of JSBSim ( Flight Gear ) you'll find even deeper complexity in terms of flight dynamics modelling.

Then, if you carefully analyse how a flight model is "merged" / "consolidated" with it's pre-mfs form, by integrating the various stability derivatives with those supposedly obtained via the new approach followed by ASOBO, as you can check using Dev Mode, it looks even more massaged then innovated... ( so far )

The parameter introduced some SUs ago ( believe SU6 ? ) to "tune" the control inputs ( don't recall the name of the GUI parameter you can access from the controllers setup screens ), actually incorporates a time delay on the various axis and was their so far "best" way of dealing with control reponse due to dynamic pressure in aircraft with no FBW ( although it affects all aircraft if you do not customize the control inputs porperly through the rather awkward Controllers GUI), and is nothing compared to what simulators like IL-2 or DCS do with their flight dynamics modelling approaches, were it is variable with "q" ( dynamic pressure ) over the corresponding control surface, and one can even see it in play as propwash hits them still on the ground if they are at an angle with the relative flow.

Control forces CAN be "negative", although yes, in MFS and regarding what I believe you're referring to, they aren't yet modelled with such detail ( nor were they in previous versions of the sim ike fs9 or fsx ). Actually really interesting ellasticity effects play thgeir role IRL even on a rather "simple" glider aerodynamics, not to mention effects due to shock waves, or the use of "negative" control inputs in order to overcome effects due to aircraft negative or neutral stability, etc...

This doesn't mean I do not acknowledge ASOBO's will to make MFS a really interesting and more, or that I do not enjoy playing MFS, or that I do not place big expectations on their recent announcements regarding flow modelling aproximations and prop physics, just trying to show that what Robert, with years of his life dedicated to the creation of some of the Best tittles for fs9 and fsx / p3d. I miss Tom Goodrick's excellent notes on flight dynamics modelling in MS Flight Simulator - he would surey contribute to make us undertand it better and, ABOVE ALL, I miss my ALL TIME REFERENCE for Flight Dynamics and their modelling in Flight Simulator - Ron Freimuth - with whoom I learned so so much !  I would be typing like mad messages to exchange with Ron if he was still between us, and I am sure I would receive back the LIGHT !

(*) Just a side note on the various mistakes about the references to X-Plane's flight dynamics model that were written in one of the documents linked above, when it was initially released by ASOBO...

Edited February 27, 20224 yr by jcomm

44 minutes ago, jcomm said:

Control forces CAN be "negative", although yes, in MFS they stll aren't modelled with such detail

Imho you missed what control forces are. In 99% of our flight control setups, the springs in the yoke or flightstick dictate the control forces. The force simply correlates with deflection. The properties of control harmonization can not be recreated that way. Negative forces are simply not possible. The simulator software, no matter what brand, can't do anything to change these.

How should the simulator simulate increasing (positive) force on the stick, dampening the deflection, suddenly tipping over and then amplifying the deflection? These things are not modelled in any simulator. Therefore I guess Rob did mean something else when he talked about control harmonization.

And, btw. I can't find deeper complexity in the JSBSim documentation. Do you have a specific example?

 

4 hours ago, Krakin said:

He might have you mixed up with Randazzo.

Ah - I see. In which case I apologise.

3 hours ago, mrueedi said:

Imho you missed what control forces are. In 99% of our flight control setups, the springs in the yoke or flightstick dictate the control forces. The force simply correlates with deflection. The properties of control harmonization can not be recreated that way. Negative forces are simply not possible. The simulator software, no matter what brand, can't do anything to change these.

How should the simulator simulate increasing (positive) force on the stick, dampening the deflection, suddenly tipping over and then amplifying the deflection? These things are not modelled in any simulator. Therefore I guess Rob did mean something else when he talked about control harmonization.

And, btw. I can't find deeper complexity in the JSBSim documentation. Do you have a specific example?

 

No satisfying implementation for the typical hardware used on desktop setups, but surely possible with force loaded controllers, as used by some more sophisticated home flight simulator setups and, of course, in "full Level-D flightsims".

If you were referring to control forces on desktop controllers, then I did missinterpret that. I thought you were referring to negative control forces in RL flying / aerodynamics.

Regarding JSBSim, such stuff as simply being able to pick stability and control data extracted from RL flight tests and feed those tables to some of the simulation variables used in JSBSim, or, to give you another rather simple example, the way ground effect can be modeleld in JSBSim as opposed to the rather simplistic and myope view of ground effect without taking into account, for instance, the differential contribution of the main wings and tail surfaces, or the actual modelling of the downwash variation in ground effect closer to the ground. These can probably be completed with the upcoming SU9 updates, but I have to wait for that before I can make any further comments...

Also, at it's present state MFS's fdm still models torque effect in a "scripted" ( to use your designation ) way, by nilling it after 1,5 Vs1 on prop aircraft. This will hopefully change with SU9.

More on this in a post of mine some pages behind on this same thread:

 

Edited February 27, 20224 yr by jcomm

1 hour ago, mrueedi said:

I try to understand, what you mean by that.

How is this a cut down version of this?

It is clear, that MSFS tries to accomplish realistic flight characteristics in a much more comprehensive way. The 100% scripted behaviour of FSX is basically uncompatible with the flight physics as implemented in MSFS. So a lot of FSX parameters are of no use anymore for MSFS. MSFS is a paradigm shift and devs need to adapt. The endless parameter tweaking is gone. Randazzo is saying, that in MSFS he is able to implement certain flight handling characteristics as he was not able before.

Also, to be a bit more precise, if you follow e.g. this procedure, in what way would the result be underwhelming? Be very speciifc and precise please.

Because saying the following made not much sense to me:

What do you mean with harmonised controls? ...

 

You ask fair questions. I need some sleep and a rest first but I will try to answer you in the next day or so.

2 hours ago, mrueedi said:

Also, to be a bit more precise, if you follow e.g. this procedure, in what way would the result be underwhelming? Be very speciifc and precise please.

 

Whilst waiting for Robert's response,  which will likely be much more concise and clear than my own, I'd just like to take this one question and try to give you some idea why it is underwhelming from a dev's perspective.

 

I have used that exact procedure - note early in the document it states that "The new flight model for  Microsoft Flight Simulator relies on the shape of the aircraft to predict its aerodynamic behavior and we have almost entirely dropped the use of tables of data. Because of this, the correct definition of the aircraft's dimension data is of particularly importance."

To give one (of several) places where this dimensional data input falls down, we go to define the shape of the fuselage and have

https://ibb.co/qy6kBpX

which is basically a cylinder. None of the aircraft that I have developed have a basic cylindrical fuselage - there are flat sides, wider/taller and narrower tapered sections. Put simply, it is too simplistic! No allowance is made for 'out of the ordinary' shapes - biplanes, delta wings, even swept wings have caused serious problems. Earlier discussion about the available parameters which we could use to make up for deficiencies comes into play here - there are not nearly enough to make up for the lack of accuracy and, on occasion, create the 'scripted' behaviour which can be better than not having that behaviour at all when it is noted by both current pilots and operating manuals.

 

I have been fortunate in that the aircraft I have been working on are nearly all ones I worked on in either P3D or X-Plane, so I know their manuals well and have contact with current or as recently current as possible pilots who test for me. In every one of these projects, whilst I have seen a much better interaction with the environment I have been noting multiple instances of basic aerodynamic behaviours which are simply not present or (even worse) wrong in MSFS, despite having been present in the other sims. That in itself, and our inability to do anything to correct it because the "tables of data" that are referred to would be really very useful to either correct or create these situations, give what is a very underwhelming result for me as a developer.

2 hours ago, Delta558 said:

I have been fortunate in that the aircraft I have been working on are nearly all ones I worked on in either P3D or X-Plane, so I know their manuals well and have contact with current or as recently current as possible pilots who test for me. In every one of these projects, whilst I have seen a much better interaction with the environment I have been noting multiple instances of basic aerodynamic behaviours which are simply not present or (even worse) wrong in MSFS, despite having been present in the other sims. That in itself, and our inability to do anything to correct it because the "tables of data" that are referred to would be really very useful to either correct or create these situations, give what is a very underwhelming result for me as a developer.

Hi Delta558.  Are you also a 3rd party developer? Are you representing Just Flight?  I'm curious because I don't understand the context of your paragraph above, you seem to be a 3rd party add-on developer based on that paragraph.

I am a 3rd party dev, I work for a couple of companies but my views are entirely my own and I cannot say that they represent any company. They are based on 15 years of working on flight dynamics for simulators and, whilst my views may often appear quite negative with regard to MSFS, I actually like a lot of aspects of it including the interaction with the environment. I strongly disagree, though, that it is a massive step forwards aerodynamically at this point in time. There is a lot of promise, but to go back to that paragraph you reference I am finding that no matter how closely I follow that tutorial or use my experience to build on it, the results are (to me) nowhere near where they should be. 

13 hours ago, robert young said:

This is factually incorrect in every sentence! Asobo have never contact me

I'll just stop you there and haven't read the remainder of your reply. I was referring to Robert Randazzo, as I thought the person I was replying to was.