P3Dv3

[mgh 89]

There's no need to develop a new flight dynamics model for PreparD. You can develop an external model using Simconnect.

 

An external model can include the specific details for a particular aircraft much better than  a simplified generic model.

[Duncan Odgers 125]

You folks that want the physics changed, some things to think about such a request:

 

1. High probability it will break any and all existing aircraft functionality except perhaps those 3PD that code their own physics (or partial physics, like A2A, Majestic, etc.)

2. You'll need to be VERY specific about exactly what needs to be changed/added, a global "change it" will not hold much consideration

3. CPU costs (in terms of processing cycles, as you increase physics accuracy you increase CPU processing demands)

 

LM certainly have a wealth of resources to draw from when it comes to flight physics so who knows what may come down the pike in the near future.

 

I think LM's stance with Physics is to provide whatever it is 3rd party need to do their own flight dynamics.

 

Cheers, Rob.

Hi Rob

 

Yes I agree with breaking compatibility but if LM go 64bit it will break compatibility anyway so may as well go the whole hog. The "other sim" boasts superior dynamics over ESP and FSX.

 

In terms of specifics Ground handling is a definite one as taxiing and breaking distances are unrealistic.

 

I guess also I have invested a lot of money in P3D in don't want to change to the other dim because it has a better feel. Some claim a Level D experience. Rob can you help answer my fears that this perhaps is not the case. I guess I'm thinking is FF777 so much better to fly then PMDG 777 in terms of feel and dynamics.

 

Thanks

 

Duncan Odgers

[Glynn 405]

The "other sim" boasts superior dynamics over ESP and FSX.

don't want to change to the other dim because it has a better feel.

 

 

One regular poster here who has built and flown his own aircraft says that this is not necessarily true.

Another user here who is a flight instructor also agrees with this, I would guess those guys know a bit about the feel of an aircraft in flight.

 

Xplane users will emphasise the "superiority" of it's flight model because that is the only thing that is subjective and not easily proved or disproved. compare everything else about the two sims and Xplane comes out looking worse, Seasons, weather, Ai, Atc, airports, quality and number of addons ect.

So understandably the XPlane guys never use these things as a yardstick to judge the two sims by.

[Guest]

Yes I agree with breaking compatibility but if LM go 64bit it will break compatibility anyway so may as well go the whole hog.

 

That seems to be a misconception shared by several ... 64bit is not just a On/Off situation, there are degrees of change.  Like I said earlier a complete re-write is NOT going to happen (and should NOT happen) ... 64bit in it's best case for a 3PD is a simple case of load Visual Studio, recompile to 64bit, and charge customers a fortune for an update ... hehe ... no, but seriously hopefully 3PDs will charge based on work effort put into the 64bit update to their product(s).

 

If you are referring to XP10 as the "other sim", I have that sim and use it on occasion (usually after every new update comes out to see how it's progressing) ... I will disagree with anyone that says XP10 flight dynamics are better than FSX or P3D ... they are different, but I can't say I'd use the word "better" and it certainly isn't a "selling point".  Some of their XP10 aircraft hit the posted limits (max/mins) better, but some are way off also (same as with FSX/P3D).

 

My real world exposure to aircraft is very limited, C172, Seneca, Piper ... I have NO experience with anything remotely commercial so I can't comment on things like the FF777 vs. PMDG 777 vs. CS777 ... I have no clue, just go with whatever they provide and accept it.

 

A2A's Piper and C172 is the closest flight dynamics I've encountered to those aircraft I've actually flown (still getting my PPL, some year) ... but still not the same as real world experience ... real world seems easier to taxi and fly to me but maybe that's the FPS difference ... hehe.  

 

But as I said before, LM are most likely to leave physics to those that produce the aircraft but they are open to suggestions but those suggestions would probably come from folks like PMDG, Majestic, A2A, and others that produce aircraft ... these folks can articulate the necessary details.

 

But hey, if you like the XP10 flight dynamics, keep that flight sim on board, I do.  If you're into combat sims, DCS base is free ... however aircraft are not ($50-$60) ... and I know even less about combat aircraft flight dynamics.

 

The only consistent between the 3 products I use is that they all eat up my hardware for lunch ... can never have "enough" hardware.

 

Cheers, Rob.

 

EDIT: but like I suggest, the best way to present your desires to LM is to list out with specific details exactly what you think is missing, for example your Taxi ... what is it about taxi physics that doen't work for you, prop inertia, ramp up, steering sensitivity, wheel drag, etc. etc.

[Duncan Odgers 125]

Thanks Rob that is great.

The taxi situation is all about the ground friction modeling.

[Pete Dowson 554]

My real world exposure to aircraft is very limited, C172, Seneca, Piper ... I have NO experience with anything remotely commercial so I can't comment on things like the FF777 vs. PMDG 777 vs. CS777 ... I have no clue, just go with whatever they provide and accept it.

 

My real world experience, years ago now, before my eye problem deteriorated too much, was in Cessna 150A, 152 and Piper Cherokees. My experience with the "other sim" was disappointing, even though like a sucker I kept buying each subsequent version, just to see. The dynamics were definitely perhaps more like the real thing near the edges of normal performance, but it seemed much too much "on rails" within the normal envelope.

 

With airliners I think the best hope is that they behave according to the numbers. Maybe experienced airline pilots can tell, but even they would normally be using autopilot, so you'd need proper test pilots. I think, for airliner simulation, having the numbers, turn rates, performance and so on matching the real thing is as good as you're likely to get.

 

A2A's Piper and C172 is the closest flight dynamics I've encountered to those aircraft I've actually flown (still getting my PPL, some year) ... but still not the same as real world experience ... real world seems easier to taxi and fly to me but maybe that's the FPS difference ... hehe. 

 

Real world flying in a light aircraft is MUSH easier than in a sim. I think it is all because of full 3D wraparound visuals (yes, at as high "frame rate", but I don't think that's the reason), plus the feel, the full seat of the pants understanding of what the aircraft is doing, what it is experiencing. I've tried all sorts of addon gadgets for the latter, to no real avail, but the former is now a waste of time because my RP has reached the stage where I have such narrow tunnel vision that 3D and wrap-around vision doesn't even really apply in the real word, let alone in a sim! ;-)

 

Pete

[Berike 13]

That seems to be a misconception shared by several ... 64bit is not just a On/Off situation, there are degrees of change.  Like I said earlier a complete re-write is NOT going to happen (and should NOT happen) ... 64bit in it's best case for a 3PD is a simple case of load Visual Studio, recompile to 64bit, and charge customers a fortune for an update ... hehe ... no, but seriously hopefully 3PDs will charge based on work effort put into the 64bit update to their product(s).

 

If you are referring to XP10 as the "other sim", I have that sim and use it on occasion (usually after every new update comes out to see how it's progressing) ... I will disagree with anyone that says XP10 flight dynamics are better than FSX or P3D ... they are different, but I can't say I'd use the word "better" and it certainly isn't a "selling point".  Some of their XP10 aircraft hit the posted limits (max/mins) better, but some are way off also (same as with FSX/P3D).

 

My real world exposure to aircraft is very limited, C172, Seneca, Piper ... I have NO experience with anything remotely commercial so I can't comment on things like the FF777 vs. PMDG 777 vs. CS777 ... I have no clue, just go with whatever they provide and accept it.

 

A2A's Piper and C172 is the closest flight dynamics I've encountered to those aircraft I've actually flown (still getting my PPL, some year) ... but still not the same as real world experience ... real world seems easier to taxi and fly to me but maybe that's the FPS difference ... hehe.  

 

But as I said before, LM are most likely to leave physics to those that produce the aircraft but they are open to suggestions but those suggestions would probably come from folks like PMDG, Majestic, A2A, and others that produce aircraft ... these folks can articulate the necessary details.

 

But hey, if you like the XP10 flight dynamics, keep that flight sim on board, I do.  If you're into combat sims, DCS base is free ... however aircraft are not ($50-$60) ... and I know even less about combat aircraft flight dynamics.

 

The only consistent between the 3 products I use is that they all eat up my hardware for lunch ... can never have "enough" hardware.

 

Cheers, Rob.

 

EDIT: but like I suggest, the best way to present your desires to LM is to list out with specific details exactly what you think is missing, for example your Taxi ... what is it about taxi physics that doen't work for you, prop inertia, ramp up, steering sensitivity, wheel drag, etc. etc.

Hey Rob,

 

I'm confused, I saw a post last week about P3D not going 64bit, thought that weird and now you mentioned 64bit version.

So P3D will go 64bit?

 

As you said, changing P3D to 64bit, requires many level of changes, but can have both supports for addons, 32/64, just a matter of how it will address it to the OS, I'm sure LM is capable of doing it, and the major addon developers follows LM SDK, so it won't be much problem to make those changes.

[ADamiani 470]

That about the flightmodel is an interesting debate. I reckon that P3D's dynamics are based on lookup tables: for each flight configuration, given certain coefficients that model the aircraft behaviour, a lookup is performed which gives the next aircraft state, and so on.

 

The "other" sim is based on a geometric approach: the aircraft is analyzed and broken into parts, then a finite element routine is applied to each part in order to determine its beahaviour through the airstream. resulting forces are derived and applied to a Newtonian model, which in turn determines the 6-component acceleration needed to update the actual updated aircraft state.

 

As a mathematician, I have no reason to prefer one model over the other: final performance compared to the real thing it the only thing that counts.

 

What really bothers me is what we mean by "improve the physics" of the flightmodel. I am sure that the guys at LM know something about the physics of flight, its simulation, and behaviour inside and outside the envelope.

 

But the real question is: what are we actually asking for?

 

Andrea

[mgh 89]

 

 

applied to a Newtonian model, which in turn determines the 6-component acceleration needed to update the actual updated aircraft state.

 

P3D, ESP, and FSX all use "a Newtonian model, which in turn determines the 6-component acceleration needed to update the actual updated aircraft state."

 

 

 

But the real question is: what are we actually asking for?

 

How many of us could use it if we got it?  Where, for example, where  would the updated data could from - the different manufacturers computational fluid dynamics models?

[gfd 15]

 

 

But the real question is: what are we actually asking for?

 

Bingo!

[LAdamson 240]

With the exception of helicopters, the other sim superiority over lookup tables..............is a marketing myth. I'm not a real fan of helicopters, even though I flew R/C copters for years, and have a good half hour of straight & level, and a few minutes of hover in a four bladed turbine helicopter. I personally thought that the other sim copters are a bit on the sensitive side, and perhaps the msfs versions had a better sense of feel. But all in all, supposedly those X-Plane copters do things better. That's what I hear anyway. As to airplanes, I'm at a total loss as to why the other sim is supposedly better. I built and flew higher performance GA. I tested GA airplanes for proper rigging. Well designed lookup table airplanes such as RealAir simulations, do a very good job at imitating flight dynamics.  They still do cross control maneuvers such as slips, better than the other sim.  X-Plane is often thought of as being more "challenging".  I see that description often. Airplanes shouldn't be that challenging. If they are, then someone needs to look into the rigging. I've certainly flown out of rig, challenging to fly airplanes, and didn't like it.

My kitbuilt RV6A was a perfect example of rigging perfection. Just an absolutely delightful plane to hand fly and trim. At the same time, it's stick was far more sensitive than a Piper or Cessna yoke for maneuvering.  

 

I do also enjoy the other sim (X-Plane). Just never found it's flight dynamics to be superior.  When I see the claims that they are, it's usually for the wrong reasons.  Whether it's look up tables or blade element theory, it's those programmers with years of experience, who make the

models believable. With lots of work, it can be done for either method.  

[SimonC 115]

 

 

But the real question is: what are we actually asking for?

 

How about 64bit and DX12? Get rid of OOM errors and make a performance-leap? (DX12 potentially is about 10x faster than DX11 when it comes to object batching!)

[gfd 15]

How about 64bit and DX12? Get rid of OOM errors and make a performance-leap? (DX12 potentially is about 10x faster than DX11 when it comes to object batching!)

 

I have a question about that. I am not an IT person. I read that DX12 will dramatically increase the number of draw calls that can be made? I assume this is related to object batching. Assume 64 bit is coming as well. If so, does this mean that the simulator will be able to call more scenery in a given time frame with the same resources? Then, does that also mean that it will be easier for a developer to create a happy medium between increased memory use; and increased draw calls, to limit the need to access unreasonable large amounts of avaiable memory space? If the reply would be too technical for me, then it's OK...take a pass. I am just fascinated by what I see as some revolutionary changes that may be coming to the most demanding software I have ever used.

[vck 0]

As mgh said, all the flight sims are based on the 6 DOF equation of motion. P3d and FSX use the lookup tables to determine the aerodynamic forces and damping based on the attitude, velocity, angular rate and a lot of other atmosphere states. All the aerospace companies like Boeing and LM use this approach to design and simulate the real aircrafts. Instead of the simple lookup tables, they use the aerodynamic database contains vast amount of the wind tunnel data with corrections from the actual flight test.  For the commercial aircrafts, the database has to be certified by FAA to be used in the fixed or moving base flight simulators manufactured by CAE, L3, Rockwell Collins, and others.

 

I have to give credit to XP's creator by creating a plausible flight behavior (not flight dynamics) just like his plausible world. However, please don't confused it with the finite element methods used in the computational fluid dynamics analysis. XP simply kluges together a few elements (which has nothing to do with the actual 3D geometry of the airplane) and integrating those forces (from airfoil tables)  to get overall forces and moments. There is no consideration of the interactions between those elements. The moment of inertia estimations are likely to be very inaccurate and there is no direct damping force calculated on any axis. No wonder some XP airplanes are less stable and more responsive, which confuse by some of the XP followers as the superior dynamics. 

[DarkstarF16 72]