The B737 Classic Project

[Nicola_M]

Thank you so much Tom, for

1. making me drool 

2.  making me realise at some point I am going to have to buy xp10.

3.  and a new pc.

4.  the panic in the realisation that I haven't got a clue where to look if I want a Windows capable laptop capable of running XP10

5.  as a result of (3) I'll have to endure the steep learning curve of Windows 7

6.  as a result of (4) there are certain programs I use that will now involve a close encounter with the joys of PPJoy.

7.  as a result of (2), (3) and (5) I'm either going to need to take out a mortgage and/or rob a bank to pay for the hardware I need to run the 737.

 

But what a journey it'll be....

[meshboy]

I cant wait to see some of the galley. I love to sit in the back while replaying takeoff or landing. I think the galley is very important for overall fell. Will seatbeltsign and smoke sign work in the galley?

[tkyler]

 

Will seatbeltsign and smoke sign work in the galley?

 

 

It wouldn't be a study sim if they didn't eh?   That's the easy stuff

 

TK

[Nicola_M]

About the one and only thing this 737 won't come with is airline food.

 

Am I right in thinking the IXEG 737 is going to be a groundbreaker across all sims?  Don't think PMDG/CaptainSim or anything else in FSX has had the level of realism and believability this 737 has.

[tkyler]

 

Don't think PMDG/CaptainSim or anything else in FSX has had the level of realism and believability this 737 has.

 

 

I can't speak for those having not tried all of them, but we have taken stock of all the current offerings out there, their level of 3D animation and texturing and believe we have some cutting edge stuff for sure, we certainly like where we are with our 3D immersion.  We also interviewed several ardent users of PMDG products and we demonstrated it to a few folks at the AVSIM Fancon conference and was received extremely well there.   It will ultimately be up to users though to decide how we stack up. This is our first effort after all and there are some challenges remaining that we have yet to see how we'll do.  All we know is that we want to feel like we're in the real thing for every possible sensation we can cram into it and though time is important, getting it right is moreso,  and being a 737, we don't have airline food, but if you keep a close eye on the AC ammeter gauges  shortly after takeoff, you might catch some evidence of the coffee maker being turned on

 

TomK

Edited May 15, 2013 by tkyler

[X-Plane Australia]

(5) I'm either going to need to take out a mortgage and/or rob a bank to pay for the hardware I need to run the 737.

 

Bank job sounds like a good idea?

 

Tom, can I see FSX style reflections on that fuselage or is that just brilliant texturing?

[tkyler]

 

Tom, can I see FSX style reflections on that fuselage or is that just brilliant texturing?

 

 

It's a brilliant static reflection by Nils....until such time as X-Plane gives us dynamic reflections....which will happen some day.    A lot of the "plastic pieces" in the cockpit have subtle reflection effects done by Nils also and is one of the major reasons the cockpit feels so immersive.

 

TK

[Michel]

As far as I understand the deeper workings of X-Plane, the sim computes forces and moments based on the geometry of the aircraft, right? 

 

My question is: do you guys as developers "only" have to create a highly accurate model of the aircraft and then give it to X-Plane? As in, the sim will take care of the rest and create an accurate dynamic behavior of the aircraft? 

 

I find it hard to believe that X-Plane is THAT accurate. After all, CFD software used in the aerospace industry needs hours to complete computations on one flow condition, while X-Plane does it 30 times per second. I understand that the desired accuracy is a lot lower but still...

 

It would be awesome if you could give us some insight into that! How do your tune your model to behave like the real thing?

Edited May 16, 2013 by Michel

[tkyler]

 

As far as I understand the deeper workings of X-Plane, the sim computes forces and moments based on the geometry of the aircraft, right? 

 

My question is: do you guys as developers "only" have to create a highly accurate model of the aircraft and then give it to X-Plane? As in, the sim will take care of the rest and create an accurate dynamic behavior of the aircraft?

 

 

That is a heavy topic best suited for another section Michel, but in general, yes, x-plane computes forces on elements based on the geometry....but as you surmise, its a very "first pass" approximation and the "geometry part" only applicable to a narrow range of the entire model.    It is my opinion that there is a perception that if one enters highly accurate information across the board, that x-plane will handle the rest, which means that if once can simply access such information, then anyone can make a high quality model, which is why we have people with naught but 3D experience building flight models.   What x-plane has is a "series of methodologies" for simulating certain aspects of an aircraft.  Forces on elements uses one technique, BEA or FEA if you will, drag another, slipstream effects another, etc and each technique has limitations, assumptions and approximations.   There is no guarantee that the technique that Austin has decided to use is the best to represent a certain behavior, he may have been in a rush to get XP out the door.....but by understanding it, we can 'bend' it if we know the real underlaying physics and that's what we do at IXEG.   Understanding of not only the engineering principles behind any given behavior, but also numerical techniques or state models to approximate such behavior are a pre-requisite for getting really good results IMO.  

 

CFD goes to the n-th degree (or can),  calculating complex flows from N-S equations that x-plane neither seeks nor needs to do.   In typical numerical element modeling, one always has to choose a "convergence level" that is good enough and this is what x-plane does.   it's a 80 dollor sim and is as good as any sim for basic flight simulation.

 

A few examples.   The geometry of the aircraft is suitable for caculating force vectors on elements against relative airflow, nothing more.  It is not suitable for momentum effects, gyro effects or parasitic drag effects or vorticie effects.    The mass model is simple a 3D matricie of point masses which is suitable for calculating momentum, but has to make "guesses" as to structural densities or "common equipment" and therefore only approximates moments of inertia.    The slipstream model makes assumptions about conservation of energy and prop efficiency and applies a simplified forcefield to the wing elements (but not fuse elements), etc.   So the whole is a collection of parts and while x-plane will handle about 70% of the workload for you simply by entering information, getting really good performance and feel means having a deeper understanding of how x-plane goes about its business and then using some programming tools to try and pick up the leftovers.   Having experience in numerical methods myself, I can usually guess how Austin might have chosen to do something, but I have called him on a few occasions to find out what's he's done.  The bottom line here though is understanding what x-plane is and isn't trying to do.  X-Plane isn't trying to be a CFD tool, it isn't trying to be aerospace design software...it's a recreational flight simulation that uses a reasonable engineering model to simulate flight that has some pros to it that lots of folks like, including myself.

 

TomK

Edited May 16, 2013 by tkyler

[Morten]

How do your tune your model to behave like the real thing?

 

Tuning the flightmodel in XP to the level we are at requires;

- Very good understanding of how XP works

- Very good understanding of how the real world works

- Access to very hard to get information of the aircraft and engine.

- Have the knowledge to understand the documents and information you have

- Access to the real aircraft and a full motion simulator

- Programming skills, to make up for some of XP's inaccuracy's

 

When you have all this it's time to start calibrating.  You now know where you are, where you want to be, and have the

tools to get there.  Then it's basically a matter of callibrating everything IN THE RIGHT ORDER.  If you don't, you

will be running around in circles, like someone lost in the forrest.  The key word here is reverse engineering and in sim testing.

 

Offcourse, the average designer will enter ballpark numbers into PlaneMaker and airfoils etc, and the end result will in best case

be a ballpark flightmodel.  Garbage in = garbage out.  Getting the 3D right is offcourse important, but then maybe 10% of the work is done.

 

We offcourse expect some people to pick apart our planemaker model and airfoils etc and analyze them and maybe find some "strange" stuff there,

but that will not get you very far unless you also have our code.  It's the combination of the two that make up our flightmodel in the sim, so you

will have to judge the aircraft from within the sim. 

 

M

Edited May 16, 2013 by Morten IXEG

[Michel]

Thank you Tom and Morten for your time to answer! Insightful answers, very much answers my question.

 

So does that mean that geometry the user sees in the sim is not the same geometry that X-Plane runs the calculations on?

 

Morten, what you write makes we wonder: If you have to create some "strange" airfoils and models in order to get it right, isn't that in a way against the philosophy of X-Plane? Don't get me wrong, I'm a huge fan of the approach X-Plane takes, I'm just interested in how things work and why things are done in a certain way.

 

My own guess would be that the approach X-Plane takes (i.e. give it a model and get the result "for free") works reasonably well for standard aircraft configurations and flight regimes. While that is a major strength of X-Plane (anyone can create aircraft or you could even use it as a priliminary design tool) it doesn't really cut it anymore for the precision that IXEG is looking for. 

[Cameron]

So does that mean that geometry the user sees in the sim is not the same geometry that X-Plane runs the calculations on?

 

That's correct.

 

My own guess would be that the approach X-Plane takes (i.e. give it a model and get the result "for free") works reasonably well for standard aircraft configurations and flight regimes. While that is a major strength of X-Plane (anyone can create aircraft or you could even use it as a priliminary design tool) it doesn't really cut it anymore for the precision that IXEG is looking for. 

 

That's essentially verbatim what Tom stated, so you have that assumption correct. For an $80 sim it is quite impressive in its ability to provide realism and enjoyment within the realm of reasonable expectation for the price. It can be debated all day long, but of all the sims out there in this price range, many of us feel X-Plane provides the most realistic approach you can get.

 

Morten, what you write makes we wonder: If you have to create some "strange" airfoils and models in order to get it right, isn't that in a way against the philosophy of X-Plane? Don't get me wrong, I'm a huge fan of the approach X-Plane takes, I'm just interested in how things work and why things are done in a certain way.

 

Morten can answer this further, but I view this answer as a 'yes' and a 'no' one. We already know that X-Plane's approach by itself is not 100% there, but does quite a good job for any enthusiast or developer. In the instance of Morten and the IXEG guys, they want more out of X-Plane (going off of what he has already said) and they know how to get it, even if it takes reverse engineering. They are bending the sim to be even more realistic than it's intended to be, and above all, we can't expect these guys to share every secret they have in their inventory.

[Tom Knudsen]

Seems your youtube channel is getting outdated

[tkyler]

 

 If you have to create some "strange" airfoils and models in order to get it right, isn't that in a way against the philosophy of X-Plane? Don't get me wrong, I'm a huge fan of the approach X-Plane takes, I'm just interested in how things work and why things are done in a certain way.

 

 

 

The primary thing to keep in mind here is the concept of "math modeling" of a behavior.  When any engineer decides to model something mathematically, they will have to make choices about how to go about doing so.  The "x-plane approach" is a sound approach, but doesn't guarantee that Austin has yet implemented any given feature or relationship accurately.  For example, ground effect due to air compression.  This is something that Austin might choose to 'approximate' by altering aero forces close to the ground.  He might come up with some heuristic function relating wingspan to lift and apply that to his equations.   We may find that his choice of model was lacking for some reason...perhaps he was in a hurry or didn't feel like digging up research or thought "this is good enough and nobody will know"....and in such a case, we might seek to alter that behavior to get even more accurate.  Just because Austin wrote the code does not mean that adopted the correct math model for a behavior.   So we feel we do not go against the x-plane philosophy, but rather seek to improve the areas that Austin has yet to either get to or has no interest in getting to.  So for any given behavior, usually the first thing we do is assess how well x-plane simulates something....and if it comes up short, then we try and find ways to improve it.  Being that we are multiple guys working on one project (as opposed to Austin working on 3 or 4)...then it's more reasonable for us to spend lots of time fixing one area while Austin is dealing with dozens of other issues with mobile or his VP400 AP system, etc.   The challenge for aircraft developers is to assess x-plane and making note of what it does well and what it does not do well.  Austin is not interested is absolute accuracy across the board anymore and is content to let 3rd party folks customize it.  I give props to the relevant Laminar team members for at least providing a way for folks to simulate that which Austin has elected not to via the SDK.

 

TomK

Laminar / IXEG

[Morten]

Morten, what you write makes we wonder: If you have to create some "strange" airfoils and models in order to get it right, isn't that in a way against the philosophy of X-Plane? Don't get me wrong, I'm a huge fan of the approach X-Plane takes, I'm just interested in how things work and why things are done in a certain way.

 

No strange airfoils  XP does a great job on it's own in most areas, but if you want extreme accuracy, it needs a bit of help.  We "bend" the model if needed.

Exactly what we do in various areas I cannot tell you, but the main point is, that if you are willing and capable of going that extra mile - you can get there n XP.

So no, we are not going against the philosophy, we take it one step further and tailor it to fit the 737.

 

M

Edited May 16, 2013 by Morten IXEG

[mike10]

I recently got a hold of some Hi-Rez screenshots (Thanks to the guy with the 4Gig graphicscard ). Here are two for now:

 

MCP.jpg

 

Overhead.png

 

Edit - I just realized that the forum software cuts these down to smaller rez again . Let´s see if I find someone who knows how to avoid this...

 

 

 

WOW!! stunning

Edited May 17, 2013 by mike10

[79carboy]

Pictures pictures, were all salivating over the plane, though right now i wish it was more than pictures

[Claude D]

WOW!! stunning

 

 

they go where no one has gone before.... ....

 

Edited May 18, 2013 by Leglaude

[tkyler]

We are having fun tying in the cool parts of the simulation and wanted to share a bit.  There is a lot going on behind the scenes systems wise in this video so here is a quick commentary.     We are beginning to tie in a lot of interdependent systems code in this video.  You will see electrical, lighting and sound systems working together in subtle ways to maximize cockpit immersion.  In this video, I basically play with the generator and GPU switches...but as I do, you'll see some things happening.  You can hear cockpit fans running, there are more than one and as the power is flipped on an off, you'll note the cockpit fan noise changes a bit as a fan loses power.  Also, when switching between power sources (GPU and generators in this case) the system automatically has to disconnect one bus fully before connecting the other and this momentary disconnect of electricity causes bus loss of power which causes everything that is not on the battery bus to "flicker".  The loud sound you hear as generators are connected/disconnected are the main bus breakers, which because they carry heavy electrical loads, are big and heavy and make a loud noise in the cockpit.  You'll also note the EHSI and EADI go off and on with power...but they have a "self-test" duration period every time they power on so they don't come on as quickly as the go off.  We are still wiring up stuff in the cockpit though but thought you might have fun watching it as it progresses.

 

https://dl.dropboxusercontent.com/u/955680/breakers.mp4

Edited May 22, 2013 by tkyler

[Simmo W]

Very impressive vid Tom! I can feel that thunk.

[meshboy]

you can almost hear the electricity in the lines! =)

[Tom Knudsen]

Was that not Morten's post on X-plane.org Tom?

[Morten]

Was that not Morten's post on X-plane.org Tom?

 

 

I quoted Tom and added a couple of sentences  ​ 

 

M

[tkyler]

I posted here last night, then Morten posted it on x-plane.org as many org members don't come here so we keep folks informed at both spots.

 

TomK

Edited May 23, 2013 by tkyler

[Tom Knudsen]

Cool TomK, keep up the excellent work