SDK Contact point reference

[jfrench]

Hi,

I've been referring to the SDK in order to develop an understanding of the aircraft.cfg file. I came across this quote in the [contact_points] section:

"When importing an aircraft that does not contain this set of data, the program will generate the data from the .air file the first time the aircraft is loaded, and then write it to the aircraft.cfg."

I deleted the Contact point section from the aircraft.cfg file of an aircraft that I've been tweaking. I started FSX, selected the aircraft for free flight and was greeted with a crash and the aircraft sitting on the ground in a cloud of sparks. If anyone would provide info as to what's going on I'd certainly appreciate it. Thanks.

Jim F.

Edit: Windows XP

[FelixFFDS]

#1 does your sampled *.air file have valid contact points?

#2 the SDK lied.. or maybe you should not have deleted the section per se, and just the values??

[jfrench]

Hey Felix,

I don't know if the .air file has valid contact points and don't know how to determine this. I would be most appreciative of any further information you could provide as to how I could find out.
I tried deleting the entire [contact_points] section and then leaving the heading and deleting the rest of the section. Neither worked as advertised.
That's when I asked for help.

Jim F.

[FelixFFDS]

Originally Posted by jfrench

Hey Felix,

I don't know if the .air file has valid contact points and don't know how to determine this. I would be most appreciative of any further information you could provide as to how I could find out.
I tried deleting the entire [contact_points] section and then leaving the heading and deleting the rest of the section. Neither worked as advertised.
That's when I asked for help.

Jim F.

But does ANYTHING get written to the [contact.points] section?

[jfrench]

Hi Felix,

There was no change whatsoever to the Aircraft.cfg file. I would have indicated if any change to the file had occurred. So can you provide any information as to what I might try? How familiar are you as to what the problem might be? How do I determine if the .air file has valid contact points?

Jim F.

[jfrench]

Hi again,

I located "Aircraft Airfile Manager". I ran the program but can't determine if the the file contains contact point information. What is the name given to these values?

Jim F.

[FelixFFDS]

Look at Section 1004 [Landing Gear] and 1005 [Scrape Points]

[jfrench]

Hi,

For some reason I'm not being notified regarding new posts.
The Airfile Manager doesn't acknowledge that these sections exist in the .air file of interest. That would certainly account for the results. I'm assuming from your post and my findings that these are required to construct the addition to the Aircraft.cfg.
I've been adapting a FS2004 Cessna T-37 Dragonfly for use in FSX. It didn't want to turn on the ground and I noted that the Moments of Inertia looked as though they were copied from a much larger aircraft. They were about 5 times the value of what seemed reasonable. The only sections of the the Aircraft.cfg file that I've ever fooled around with previously were the Flightsim.x sections; what's amazing is that all of this is starting to make sense.
Thanks for your help.

Jim F.

[bobbyjack]

Jim

You might look at a utility called AirEd (at Avsim and other flightsim sites). You can probably find tutorials on what you want to do on the web. Do you have the authors permission to alter this plane? There are almost always problems porting user planes into FSX. Some can be made to work and some can not.

Bob

[jfrench]

Hey Bob,

Thanks for the info. I downloaded an apparently revised version of AirEd from Simviation but haven't had a chance to check it out yet. I found the accompanying blurb regarding AirEd interesting. Here it is:

"This upload is done because I think there are people out there who are trying to make money from the simulator community who have used their knowledge to make it harder for the average person to produce an aircraft that flys well."

The more I get into this hobby this seems to be getting more and more evident. I guess as people go over to the dark (commercial) side, greed starts to raise it's ugly head. It's only human nature.

Jim F.

[robystar]

You are wrong but you will find out for yourself how hard it is to make a decent scenery or gauge or aircraft or....
Greed, maybe for some but not for the majority.
Most of us on this forum either produced high quality addons that cost them not only time but also money in procuring the necessary programs etc. and it is not more than normal if they at least get compensated for their efforts.
Nobody will get rich on selling its scenery.
You are free to buy it, or you do not and start developing it yourself. And, not because of the money but because it is a challenge, I prefer the second.
But, please, do not underestimate the work and time those people have put into it.
I haven't released any scenery to the general public and I feel like a leech sucking out knowledge from all those that are contributing to these forums here.
Nevertheless, I hope that, once in a while, I can either add something to the forum by answering some simple questions or enliven the whole kaboodle with some sick joke .

[jfrench]

Hi robystar,

I am not wrong. I wasn't making some sort of blanket indictment of the flight simulator community. And you don't know the degree of admiration I feel for the quality of workmanship (perhaps artistry would be a better word) of what's being provided at no charge by so many. The deeper I get into this hobby the greater my appreciation grows.
I don't see any need for you to feel like a leech by availing yourself of what's being freely provided in these forums. I know that when I'm able to help someone I derive satisfaction and that's my reward. I don't think I'm alone in feeling this way. And also development for more tangible benefits is after all the basis of our civilization.

Jim F.

[robystar]

Jim,

In spite of misinterpretations of what we would like to convey, we agree on the whole, I guess.
So, what is preventing you from using the original aircraft.cfg contact points section again by cut and paste and go onwards from there?
Or is it because of the SDK that says it will rebuild the contact points from the air file?
As it is an addon FS9 aircraft, you do not know what air file has been used. Hence Bob's suggestion of using aired to check the air file.
Are you interested in how things work or do you want to have your particular problem solved?

[jfrench]

Hi,

Sorry for the delay in responding. For some reason I'm not being notified that a reply has been posted.
My main interest is developing an understanding of what's going on. The more I look into things the more apparent disagreement I see with what seems logical. By just randomly checking various aircraft I see entries that seem inappropriate (e.g. float contact points in a non-amphibious aircraft). I've referred to the SDK enough to take what I read with several grains of salt. This site seems to be frequented by the people who have the greatest technical expertise so this tends to be the first place to which I post technical questions. What prompted this particular line of questioning was an aircraft that was difficult to turn while taxing. I compared the values listed in the Aircraft.cfg with those of similar aircraft and noted MOIs that seemed appropriate to an aircraft of about 5 times the size of what seemed logical. Rather than just changing them in the CFG I started wondering were the values came from and referred to the SDK documentation. By changing the values to what seemed rational resulted in the aircraft taxing in a manner that seemed appropriate rather than like the Titanic trying to avoid an iceberg.

Thanks for your interest,
Jim F.

[hairyspin]

Tail wheel lock? edit: nosewheel!...... In any event, just because a model is published doesn't mean the FM is flawless - it just means it's published. How many have loaded up an FS9 model in ACM and discovered the contact points gave the aircraft a much wider/narrower track than the wheels would indicate? Or a scrape point that should be digging a furrow in the runway? The lack of visual tools in the SDK means third-party software - or third parties - are where a modeller's mistakes are often found.

Mea culpa as much as anyone else!