Jump to content
JimTM

Notes on AI Taxi, Takeoff, and Landing

Recommended Posts

Based on some recent testing that I did, here are some notes on AI taxi, takeoff, and landing behaviour resulting from various combinations
of takeoff command, land command, and airfield objects. For more background, see the references listed at the bottom. I'll need to update
the editor manual to reflect many of these notes. Please let me know if you see any errors.

 

  - Takeoff command, no airfield objects:

   

        The plane takes off in the direction the plane is pointing.

 

  - Takeoff command, one airfield object with no taxi path:

   

        The plane takes off in the direction that the airfield object is pointing.

 

  - Takeoff command, one airfield object with taxi path:

   

        The plane taxis to the takeoff point defined in the taxi path and takes off in the direction of the taxi path. The airfield object location and direction
         can differ from the taxi path location and takeoff direction. In this case, the airfield object location and direction have no effect on the AI plane.

 

  - Takeoff command, multiple airfield objects, with or without taxi paths:

   

        The plane takes off according to the airfield object closest to the takeoff command. See the other takeoff notes for more details

        Update: This note is not correct. More testing is needed. See this post below.

 

  - When the AI receive a land command, they fly a wide, pre-programmed circuit and then land. The orientation of that pre-programmed circuit
    depends on how you set up the land command and airfields, as discussed in the other notes in this topic.

 

  - Land command, no airfield objects:

   

        The plane lands at the land command and in the direction the command is pointing. This is the only scenario where the location and direction of
        the land command is important.

 

  - Land command, one airfield object with no taxi path:
    
        The plane lands about 300m before the airfield object and in the direction in which the object is pointing. The location and direction of the land
         command have no effect on the AI plane.

 

  - Land command, one airfield object with taxi path:

 

        The plane lands at the takeoff point defined in the taxi path and taxis in the direction of the taxi path. The airfield object location and direction can
         differ from the taxi path location and landing direction. In this case, the airfield object location and direction have no effect on the AI plane.

 

  - Land command, multiple airfield objects, with or without taxi paths:

 

        The plane lands according to the airfield object closest to the land command. See the other landing notes for more details.

        Update: This note may not be correct. More testing is needed. See this post below re. "Takeoff command, multiple airfield objects, with or without taxi paths.".

 

  - As mentioned above, an airfield object location and direction can differ from the taxi path location and landing direction. This feature can be
    useful to give AI planes a place to RTB (return to base) when they are near an air start airfield object in a multiplayer mission.

 

    You could set up an air start airfield object anywhere and then define a taxi path at any runway in friendly territory. If AI planes near your airstart
    object have "AI Return to Base Decision" enabled and they need to RTB, they return to the runway where you set up the taxi path. Be careful not to 
    move or rotate the air start object once you define the taxi path otherwise you will move the path and you will need to edit it.

 

     If you do not specify a taxi path for air start objects, AI that need to RTB land on the ground below the air start.


Tips:

 

  - For multiplayer missions where you want AI planes to taxi to and from the runway, place the airfield object that defines the taxi path closer to the
    takeoff command and the land command than any other airfield object.

    Update: This note is not correct. See the update under "Takeoff command, multiple airfield objects, with or without taxi paths".

 

  - If you want to use the "AI Return to Base Decision" option, define a taxi path for every friendly airfield object that the AI is likely to be near. You can
    define a simple taxi path that just gets the AI off the runway after landing.

 

References in the IL-2 Sturmovik Mission Editor and Multiplayer Server Manual:

 

  - Make a Plane Take Off, Fly a Route, and Land (pg. 61)
  - Make a Plane Taxi to and From a Runway (pg. 63)
  - "AI Return to Base Decision" option in Object Advanced Properties Dialog (pg. 209)

Edited by JimTM
  • Like 1
  • Thanks 6

Share this post


Link to post
Share on other sites

One thing I found is that the AI won't land on a runway amongst hills e.g. Agoy northwest of Tuapse. Shame as it's a fantastic base for 57.GIAP to use.

  • Thanks 1

Share this post


Link to post
Share on other sites
9 hours ago, JimTM said:

The orientation of that pre-programmed circuit depends on how you set up the land command and airfields, as discussed in the other notes in this topic. 

How exactly can I make the AI fly a right or left turn circuit. I can't find this information in your post.

Share this post


Link to post
Share on other sites
12 hours ago, Juri_JS said:

How exactly can I make the AI fly a right or left turn circuit. I can't find this information in your post.

 

I haven't done enough testing to determine the pattern flown for each case. In general, the AI turns 30 degrees from the final approach course, turns 180 degrees, and then turns back to the final approach course prior to landing. Whether the turns are left or right depends on the exact setup used. In some cases, the AI made some extra, small turns before beginning the general pattern I just described.

Edited by JimTM

Share this post


Link to post
Share on other sites
12 hours ago, Juri_JS said:

How exactly can I make the AI fly a right or left turn circuit. I can't find this information in your post.

 

It changes - no use trying to figure on it.

Share this post


Link to post
Share on other sites

I once managed to change the landing pattern for a mission from Anapa airfield, because the left turn circuit lead to a crash into the nearby hills. The problem is, I can no longer remember how I did it. 😫

 

It was either a change to the airfield object or to the landing command. Or maybe both?

Share this post


Link to post
Share on other sites
32 minutes ago, Gambit21 said:

Hard coded logic changed 

Damn, I think your right. I just found the old version of the Anapa mission and now the AI does a right turn circuit.

 

Nonetheless, a method to influence the the landing pattern would be very useful.

Share this post


Link to post
Share on other sites

I would like a reliable method as well.

I used to have a reliable method of waypoint placement prior to the ‘command land’ but it no longer works.

Share this post


Link to post
Share on other sites

Love the notes above JimTM and they have really helped me in finishing this Kerch Airfield Display Team mission. I managed to get two different teams taking off and landing and then taxi-ing to their own side of the airfield following the built-in taxi routes.

  • Thanks 1

Share this post


Link to post
Share on other sites
42 minutes ago, SCG_MADOV said:

Love the notes above JimTM and they have really helped me in finishing this Kerch Airfield Display Team mission. I managed to get two different teams taking off and landing and then taxi-ing to their own side of the airfield following the built-in taxi routes.

 

Well done MADOV. I'm glad that my notes helped you out.  :salute:

Share this post


Link to post
Share on other sites

Since the last update, the taxi path is ignored by the AI.
Everything worked just fine before the update.
After the update I could not open my maps with the editor. The editor collapsed immediately.
After deleting the *.msnbin files, I was able to edit my maps again. But I can not persuade my AI's to follow the taxi path.
Does anyone know the problem and can help?

Share this post


Link to post
Share on other sites
47 minutes ago, J99_Himmelhund said:

Since the last update, the taxi path is ignored by the AI.
Everything worked just fine before the update.
After the update I could not open my maps with the editor. The editor collapsed immediately.
After deleting the *.msnbin files, I was able to edit my maps again. But I can not persuade my AI's to follow the taxi path.
Does anyone know the problem and can help?

 

Can you post a problem mission please (a simple one if you have it). That will make it easier for someone to help.

Share this post


Link to post
Share on other sites

Thank you for your prompt reply!

The faulty map is online. "Jasta99-Training-WW1-WW2"

To find the bugs I reduced a map to a problem Airfield. Then I did several tests with one AI-Plane.

The AI-plane I placed in different places and in different orientations. I have found that the AI always wanted to start in the same direction. But it was not the direction in which the fakefield was directed. That's why I controlled the orientation of the airfield I'm starting from. It was the direction in which the AI always wanted to start. The AI's were based on my airfield and not on the fakefield, which was much closer to the AI.

I do not remember every detail of what I tested. I deleted the chart (taxi path) of my airfield and aligned it in the direction of the runway. The AI started now in the right direction.

Because the AI ignored the taxi path, I completely deleted the fakefield. After a few attempts with a newly created fakefield, I found a working variant. Screenshot from the editor.

test5.jpg

Share this post


Link to post
Share on other sites
On 6/18/2019 at 5:53 AM, J99_Himmelhund said:

Thank you for your prompt reply!

The faulty map is online. "Jasta99-Training-WW1-WW2"

To find the bugs I reduced a map to a problem Airfield. Then I did several tests with one AI-Plane.

The AI-plane I placed in different places and in different orientations. I have found that the AI always wanted to start in the same direction. But it was not the direction in which the fakefield was directed. That's why I controlled the orientation of the airfield I'm starting from. It was the direction in which the AI always wanted to start. The AI's were based on my airfield and not on the fakefield, which was much closer to the AI.

I do not remember every detail of what I tested. I deleted the chart (taxi path) of my airfield and aligned it in the direction of the runway. The AI started now in the right direction.

Because the AI ignored the taxi path, I completely deleted the fakefield. After a few attempts with a newly created fakefield, I found a working variant. Screenshot from the editor.

test5.jpg

 

I'm not sure where to look in your "Jasta99-Training-WW1-WW2" mission called training03.mission. By the way, you should upload the .msnbin file to the DServer rather than the .mission file because the .mission file takes longer to download to each player's PC.

 

 

Share this post


Link to post
Share on other sites
On 7/4/2018 at 1:44 PM, JimTM said:

Based on some recent testing that I did, here are some notes on AI taxi, takeoff, and landing behaviour resulting from various combinations
of takeoff command, land command, and airfield objects.

 

Just wanted to say I found this incredibly useful. I'm doing a mission where I expect the AI to actually land at a player airfield, and the taxi setup has allowed me do to this without building some specific-for-the-AI fake airfield. Thanks Jim!

  • Thanks 1

Share this post


Link to post
Share on other sites
On 7/5/2018 at 8:04 AM, Juri_JS said:

How exactly can I make the AI fly a right or left turn circuit. I can't find this information in your post.

 

On 7/5/2018 at 9:02 PM, Juri_JS said:

It was either a change to the airfield object or to the landing command. Or maybe both?

It looks like a very late advice but it depends on the wind direction.

  • Thanks 2

Share this post


Link to post
Share on other sites
Posted (edited)
On 7/4/2018 at 9:44 PM, JimTM said:

  - Takeoff command, multiple airfield objects, with or without taxi paths:

   

        The plane takes off according to the airfield object closest to the takeoff command. See the other takeoff notes for more details

 

Sorry to say but that part isn't correct (or at least seems not to be correct anymore).

I have just checked this, because if it was correct, I could have massively simplified a training mission, but unfortunately the truth is:

AI planes invariably choose the airfield which is closest to their spawnpoint for taxi to takeoff calculation.

If that airfield has no suitable chart (i.e. no chart at all, or the initial park point is too far away from spawn position, like 1km off or so), the planes will run in circles for an arbitrary time, and then take off in an arbitrary direction.

The location and/or direction of the takeoff command seems to be completely irrelevant.

 

:drinks:

Mike

Edited by SAS_Storebror
  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)
1 hour ago, SAS_Storebror said:

 

Sorry to say but that part isn't correct (or at least seems not to be correct anymore).

I have just checked this, because if it was correct, I could have massively simplified a training mission, but unfortunately the truth is:

AI planes invariably choose the airfield which is closest to their spawnpoint for taxi to takeoff calculation.

If that airfield has no suitable chart (i.e. no chart at all, or the initial park point is too far away from spawn position, like 1km off or so), the planes will run in circles for an arbitrary time, and then take off in an arbitrary direction.

The location and/or direction of the takeoff command seems to be completely irrelevant.

 

:drinks:

Mike

 

Thanks for the update Mike. I'll add a note under the takeoff command note that more testing is needed. I'll also add a note that the note for "Land command, multiple airfield objects, with or without taxi paths" may not be correct.

 

I think the taxi path decision for a plane may be dependent on the nearest taxi point to the AI aircraft, regardless of which airfield object owns that taxi point. As I say, more testing needed. 

Edited by JimTM

Share this post


Link to post
Share on other sites
1 hour ago, JimTM said:

I think the taxi path decision for a plane may be dependent on the nearest taxi point to the AI aircraft, regardless of which airfield object owns that taxi point.

I can definitely rule that out from my testing results.

Nevertheless I agree that more tests are necessary.

 

So far, the only reliable solution to me was to give the nearest airfield object a suitable taxi chart.

Actually this corresponds to AI's behaviour when it comes to picking up the landing taxi chart of choice (when AI RTB decision is active).

In that case it will also be the chart of the closest airfield to the aircraft at the time of landing decision.

The distance to the actual chart, the location of the landing command MCU etc. don't matter in that case either.

You've outlined that correctly in your summary by the way ;)

 

:drinks:

Mike

  • Thanks 1

Share this post


Link to post
Share on other sites
4 hours ago, JimTM said:

I think the taxi path decision for a plane may be dependent on the nearest taxi point to the AI aircraft, regardless of which airfield object owns that taxi point. As I say, more testing needed. 

You're right, that's the way it works.

  • Thanks 1

Share this post


Link to post
Share on other sites

As mentioned earlier, I've tried it and it doesn't work like that.

Really.

Maybe it should work like that, but it doesn't.

 

:drinks:

Mike 

Share this post


Link to post
Share on other sites

I can say for certain that after countless hours of testing, adjusting and hair pulling, that with a single airfield object present, the aircraft will divert tot he nearest taxi point - period.

I haven't tried 2 airfield objects in quite a long time time.

Share this post


Link to post
Share on other sites

With a single airfield that might be true (it makes sense after all), never said any different.

However as soon as you have multiple airfields available (for the regarding side that is), the closest airfield will win, regardless what it's taxi points look like or where they are, even regardless whether it has any.

 

:drinks:

Mike

Share this post


Link to post
Share on other sites

2 airfields were always problematic IIRC.

Behavior can also change from build to build, so I learned to avoid doing this.

Share this post


Link to post
Share on other sites

I think that we can have several cases :

 

1- One runway : if i use 2 airfields objects, i deleted the taxi path from the second one. In that configuration, i don't use 2 taxi path which can be a problem.

2- Two runways (like Pitomnik) : I can use 2 airfield with 2 taxi path which are set for each runway. It works fine.

3- The airfield is an area : i can use 2 airfields object with 2 taxi path. It works fine.

  • Upvote 2

Share this post


Link to post
Share on other sites

Thanks Habu - I’ll do some testing later.

 

Share this post


Link to post
Share on other sites

I also use different fakefields for takeoff and landing.
One can also determine that the plane should land on a distant airfield. For this I combine a 2nd ..... n. 'command land' with another fakefield. fakefield and command land should be aligned in the same direction and placed one behind the other. If I activate the remoter 'command land' with a target link, then the plane ends up there as well.
This is also useful if, for example, you want to land in the opposite direction.

It annoyed me, however, that my AI's did not react properly after the last update. Was it like that for you, too? Only after I deleted the AI's and the fakefields and replaced them with new ones did they react again correctly.

Share this post


Link to post
Share on other sites

Hum, what you describe is not a normal situation. The landing command is independant from the airfield. Airfield is just if you want that AI taxi or player spawn. 

Share this post


Link to post
Share on other sites
2 hours ago, Habu said:

I think that we can have several cases :

1- One runway : if i use 2 airfields objects, i deleted the taxi path from the second one. In that configuration, i don't use 2 taxi path which can be a problem.

A little hint about this situation.
If you need to place 2 airfields with different directions and 
taxi paths on the same runway then the airfield 01 for take-off should be placed as close as possible to the aircraft that should take off. Usually nothing works if this airfield is set far from planes.
Then everything is standard: the airfield 01 i
s active , the airfield 02 is deactivated at the beginning of the mission.

After takeoff we deactivate the airfield 01 and activate the 02.

 

The picture shows everything simplified without most of the commands for takeoff, etc.

Untitled-1.thumb.jpg.4d44edc951693287770fbe9cadb4b85d.jpg

 

Here is the complete algorithm of actions

02.thumb.jpg.894ec0c97b73adf8fb3fa94b4a28c145.jpg

  • Thanks 3

Share this post


Link to post
Share on other sites

Thank you Blacksix.

Share this post


Link to post
Share on other sites
10 hours ago, BlackSix said:

If you need to place 2 airfields with different directions and taxi paths on the same runway then the airfield 01 for take-off should be placed as close as possible to the aircraft that should take off. Usually nothing works if this airfield is set far from planes.

 

Thanks @BlackSix, that's exactly what I'm trying to get across all the time:

The distance between Airfield and Aircraft is what matters, nothing else.

This is consistent throughout the whole takeoff/landing logic, be it when the planes spawns, lands, or decides to land.

 

In @JimTM's great summary this is the only point that was wrong (and carries a note about that fact at the moment, but I take it that it will be changed soon now that there's a corresponding dev comment on that matter): Planes don't take off according to the airfield object closest to the takeoff command, but according to the airfield object closest to themselves instead.

 

:drinks:

Mike

Share this post


Link to post
Share on other sites

Hi all.

Still related to this topic: is it possible to get an AI plane not to disappear after landing (and shutting off the engine), and stay at his parked point after taxi?

 

Thank you!

Share this post


Link to post
Share on other sites

No, the Ai will disappear, to clear the position for the next AI.

 

Share this post


Link to post
Share on other sites
On ‎6‎/‎29‎/‎2019 at 4:14 PM, Habu said:

No, the Ai will disappear, to clear the position for the next AI.

 

Noted, thank you.

Another question: is there a way to get an AI plane to join a formation in the air? I mean, for example to get two AI planes to take off separately and then form together in the air?

 

Thank you.

Share this post


Link to post
Share on other sites
13 minutes ago, =OKT=Muas said:

Noted, thank you.

Another question: is there a way to get an AI plane to join a formation in the air? I mean, for example to get two AI planes to take off separately and then form together in the air?

 

Thank you.

 

I don't think so. You must target link the wingman to the leader to get the wingman to form on the leader. Because of that link, once the leader gets the takeoff command, the wingman follows. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...