GSX Pushback - Custom

[Hanse]

I have a general problem to define the custom pushback in connection with JustSim's new EDDH airport. In the configuration file it p. e. states for Gate 4

[gate 4]
hasjetway = 1
nopassengerstairs = 1
nopassengerbus = 0
disablemarshaller = 0
ignoreicaoprefixes = 0
pushback = 3
pushbackleftpos = 53.632115 10.002481
pushbackrightpos = 53.631542 10.002447
pushbacklabels = Nose Right/Tail Left (LEFT)|Nose Left/Tail Right (RIGHT)
maxwingspan = 36.0
radiusleft = 18.0
radiusright = 14.4
loadertype = 1 1
airlinecodes =
type = 8
usercustomized = 1
pushback_pos = 53.63195357 10.00419772 177.1285553

As you can see from the attached picture the actual position after PB (LEFT) seems to be OK but the direction is wrong. It is 145.51° and should be at app. 177°. So please tell me what I can do or what in the configuration file has to be changed / added so that the plane is also in the right direction after PB. Thanks in advance.

Regards,
Rolf 

[virtuali]

As you can see from the attached picture the actual position after PB (LEFT) seems to be OK but the direction is wrong. It is 145.51° and should be at app. 177°. So please tell me what I can do or what in the configuration file has to be changed / added so that the plane is also in the right direction after PB

Left/Right will lose any meaning when you are doing a custom pushback. Assume they are just like Label 1/Label 2 that you can change because, when you do a custom pushback, GSX will not try to search for a suitable point that will result the airplane pointed in a Left or Right direction but, instead, will just go where you told you to go to.

[Hanse]

Thanks Umberto for the quick reply. But even if we do not use "pushback_pos" and just "pushbackleftpos" and "pushbackrightpos" we are struggeling with the pushback function in GSX in connection with JustSim's EDDH AFCAD layout. This layout is different from other designs because the AI-taxipaths are enhanced so that there are smooth turns and the AI plane is not just making a 90° turn at one point. Please find attached the AFCAD-file for EDDH to explain the situation.

A good example for our problems is Gate 4. If there is no definition for this gate in the EDDH.ini file then the plane stops at the first taxi point after the gate and the direction is 45° degrees (left or right according to the selection) e.g. it stops too early and the direction should be 90° degrees left or right.

If there is a definition for Gate 4 in the EDDH.ini file (please see picture attached) like
pushbackleftpos = 53.63184616 10.002482235
pushbackrightpos = 53.63184616 10.002482235
the plane stops in both cases at the same point without turning right or left.

If the definition for "pushbackleftpos" and "pushbackrightpos" is changed to points on the taxiway the turn is OK but the actual position of the plane after pushback is different to what has been defined in the EDDH.ini file (please see attached screenshots Gate4 PB Nose Right and Gate 4 PB Nose Left). So what I would like to understand is what really defines in GSX the final position and turn degree in its pushback function?

A solution for me would be that the planes really stops at the position defined and not using the "nearest" node and that as well the turn degree could be defined (like if there is only one pushback option.  

So please help us to configure the GSX pushback in the right way that GSX can be used with JustSim's EDDH and for other airports with similar taxiway designs. How does the pushback works e.g. is there an SDK on which we can rely when modifying the AFCAD file or the other way around how we have to configure GSX to work properly with the current AFCAD design?

Another question is in connection with the folders / places where the relevant AFCAD file for the *.ini is saved. If both files are saved in the same folder what has to be stated in the beginning of the *.ini file? According to the manual if both are saved in the same folder no folder under [general] has to be specified. This would mean something like
[general]
afcad_path =
But according to my tests the exact location of the AFCAD file has to be specified e. g. afcad_path = E:\Program Files (x86)\Lockheed Martin\Prepar3D v3\SimMarket\JustSim-EDDH P3Dv3\data\Scenery\AFX_EDDH.bgl?  

Your help would be very much appreciated.

Regards,
Rolf    

[virtuali]

If the definition for "pushbackleftpos" and "pushbackrightpos" is changed to points on the taxiway the turn is OK but the actual position of the plane after pushback is different to what has been defined in the EDDH.ini file (please see attached screenshots Gate4 PB Nose Right and Gate 4 PB Nose Left). So what I would like to understand is what really defines in GSX the final position and turn degree in its pushback function?

The manual explains this. First, you cannot just put "any" coordinates, but you must insert coordinates of an existing node. If you don't put the precise coordinates of an existing node, GSX will use the *closest* one to the one you set, which might be or not on the correct taxiway, especially with an AFCAD with so many nodes closely spaced together.

So, first, be sure you insert the coordinates for an existing node.

And, that node will not be the exact final location of the pushback. As the manual says, it will work as an "attractor", so the truck will go in that direction, but will stop as soon as the airplane+pushback truck have been aligned.

According to the manual if both are saved in the same folder no folder under [general] has to be specified. This would mean something like
[general]
afcad_path =
But according to my tests the exact location of the AFCAD file has to be specified e. g. afcad_path = E:\Program Files (x86)\Lockheed Martin\Prepar3D v3\SimMarket\JustSim-EDDH P3Dv3\data\Scenery\AFX_EDDH.bgl?  

No folder name, doesn't mean you can even remove the FILENAME too. How GSX could even find the file, with no filename ? So, it CAN be:

[general]
afcad_path = AFX_EDDH.BGL

But of course, the full path name will work too, but it will be ignored, the only thing that matters is the FILENAME, alone. This way, you can move the scenery, or you can *share* your .INI file with anyone that could have the scenery installed in a different place, and the .INI will still work.

[Hanse]

I allways used the exact coordinates of an existing node (please look at the pictures I previously attached) and this node lays on the taxiway going into the right direction. So from my side I did everything what could be done. I would accept if there is a small difference of the final PB position but the problem seems to be the final direction of the plane after PB. Your are also writing that the stated node just works as an attractor and that PB will stop as soon "as the airplane + pushback truck have been aligned". So this additional condition seems to be the problem.

If you look at the picture attached the PB stopped much too early (far away from the stated node) and the plane also "looks" into the wrong direction. The reason seems to be that your condition "airplane + pushback truck have been aligned" was met and therefore the PB stopped. So please tell me (if there is no bug in your program) what I shall do respectivly which node I should select to get the result wanted. Or is there anyway to state the direction after PB for LEFT and RIGHT like in the case of only one possibility?

Thanks also for the explanation regarding the *.ini-file and the relevant folder. But I have another question: If I work with different AFCAD-files p. e. one normal file and another one just with a changed e. g. easier taxiway layout for GSX only. OK I m able to specify this one in the beginning of the *.ini-file. But I want to use this one just for GSX and not for all other purposes - e. g. it has to be saved not in the scenery folder. Which folder do you suggest to use and then to specify in the beginning of the *.ini-file?   

Regards,
Rolf      

[virtuali]

Your are also writing that the stated node just works as an attractor and that PB will stop as soon "as the airplane + pushback truck have been aligned". So this additional condition seems to be the problem.

That's how GSX works, and it's not a problem. Continuing to push to a node, even if you are already aligned on that taxiway, wouldn't make much sense. If you *really* want to go further, just select a node farther behind.

[Hanse]

Umberto,

1. If you look at the picture I attached to my previous mail you will see that the plane is not yet aligned with the taxiway and that the node I defined in the *.ini-file as a pushback point is far away from the position at which the pushback stopped. Then please tell me which node on that picture I should have selected to stop the pushback at the right position and with plne showing into the right direction.

2. I also added to my previous mail a 3rd paragraph regarding the *.ini-file. Please also have a look at this and tell me what to do.

Regards,
Rolf

[Hanse]

I am not satisfied with the received support or better say it in other words: No support was received in this respect. I was waiting for clear rules how to define a custom push back node and did not even get an answer. Because I wanted to solve the push back problem with JustSim's EDDH I defined those rules by myself using "try and error" and finally got a solution e.g. now push back from all gates works as required. It would have saved me a lot of time and frustration if GSX would have told me how exactly its push back function is programmed (like used tolerance to select a node, defining final direction after push back etc.)

regards,
Rolf   

[virtuali]

I am not satisfied with the received support or better say it in other words: No support was received in this respect

That's very wrong: you have been replied here, 3 times, as best as possible.

I was waiting for clear rules how to define a custom push back node and did not even get an answer

You got several answers, but I really couldn't explain it better as it's already explained on the manual.

finally got a solution e.g. now push back from all gates works as required

So the program worked, in the end. Have you find your solution to be in contradiction to what has been explained on the manual, and all my answers here ?

It would have saved me a lot of time and frustration if GSX would have told me how exactly its push back function is programmed (like used tolerance to select a node, defining final direction after push back etc.)

I'm not sure that telling you that GSX will try to fit a Bezier curve along the nodes would have helped much with your efforts, because it's not an information you can use without having some sort of debugging tools. And, it's not even possible to explain a general solution, because it depends by the length of the airplane gears+towbar+pushback truck system, so it changes depending on the airplane used and the truck selected, and sometimes a choice of a node the works well for one, won't be good for another combination.

In addition to that, there are lots of exceptions in trying to deal with mistakes scenery developers add in their AFCADs so, it's not really a place for a forum answer.

[Hanse]

I never got an answer to the questions I asked in my "Reply #6 on: March 24, 2017, 06:59:56 PM". Of course there is nothing wrong what is stated in the documentation as well as in your answers. But things / information are missing what somebody has to know if he wants to work with this feature "Customize Pushback".

One thing is that the "tolerance" of snapping another node near the definitely defined one is quite big and that additionally this node then also defines the PB direction. It would have helped a lot if the minimum tolerance / distance of the selected node (in m) to the next node would be known. Or even better if this "snapping" option could be "de-selected". And the other thing is that nowhere is stated that the node also defines the PB direction e.g. the user has to select a node on the taxiway itself.

   

[virtuali]

It would have helped a lot if the minimum tolerance / distance of the selected node (in m) to the next node would be known. Or even better if this "snapping" option could be "de-selected".

If you set the precise, exact, coordinates of the nodes, snapping won't be an issue and you don't have to know the tolerance factor.

Maybe it's not entirely clear that, a pushback node MUST be an EXISTING node of the AFCAD and snapping is used only to choose which node is the closest one, and it's done only to allow you "some" latitude in moving AFCAD nodes a bit, without usually requiring to redo the pushback customization in GSX, but it will always go to an existing node, right now, it's just work that way, but it's possible that future version will allow you to specify points that are not included in the scenery AFCAD.

[Hanse]

Hi Umberto,

if it would be like explained in your last answer everything would be OK and this is exactly what I expected. But unfortunately in reality it is different. Please have a look at my answer #4 from march 23rd and the attached picture. Even that I used / defined an exsiting node on the taxiway the plane stopped somewhere else and additional the direction was wrong...... So there seem to be additional conditions which override the ones you stated!

Regards,
Rolf

[virtuali]

Even that I used / defined an exsiting node on the taxiway the plane stopped somewhere else and additional the direction was wrong...... So there seem to be additional conditions which override the ones you stated!

Which is why I also said:

I'm not sure that telling you that GSX will try to fit a Bezier curve along the nodes would have helped much with your efforts, because it's not an information you can use without having some sort of debugging tools. And, it's not even possible to explain a general solution, because it depends by the length of the airplane gears+towbar+pushback truck system, so it changes depending on the airplane used and the truck selected, and sometimes a choice of a node the works well for one, won't be good for another combination.

So, I'll repeat it again, in order to work correctly,  a Pushback path should match ALL the following constraints:

- The coordinates nodes should be of existing nodes

- It must be mathematically possible to fit a spline (Bezier) curve from the starting position to the end position

- The curve must allow the system composed by airplane+towbar+pushback to turn correctly, otherwise it cannot be solved

Basically, a custom pushback cannot let you do "impossible" things so, in some cases, you might have to edit the AFCAD file itself, because no existing nodes might be able to satisfy these constraints.