Has anyone else noticed in FSX that your user aircraft, be it the QW 757 or PMDG series will be taxiing to the runway or stuck in traffic ahead but the plane behind you stops and stands a huge distance from your plane?! Why is that!? What is causing this???

 

An example below...The PMDG 747-400X standing still on the taxiway, and then also standing still a prop aircraft....

I would GUESS that the AI engine within the sim is aware of the position of other aircraft objects in each AI object's vicinity and maintains a specified distance behind anything situated on each AI object's intended path. I'd expect that this is parameterised somewhere in a configuration file but I wouldn't bank on it.

 

Is your point that you don't want the trailing aircraft to stop (let it play through?) or you just want it a bit closer? There are RW guidelines for how close a GA aircraft should get to another in flight. On the ground I think it's often based on common sense though a controller will normally determine the sequence. Hitting things can really ruin your day.

 

Z

The aircraft radius or bounding box in the exterior model file seems to be too large.

 

You can edit the model's radius with RADItor.

http://www.fsdeveloper.com/wiki/index.php?title=RADItor

Might i add this is the case with ALL AI traffic, 747s, A32Xs etc etc, so i believe this distance thing has something to do with the user aircraft?

 

I want the AI to be closer as real life traffic would queue up, but having traffic so distant is alittle strange. It doesnt ruin the sim but i would be interested to see if a fix can be found as this wasnt the case in FS2004.

 

Ill post a few more example screenshots later...

I was told it had to do with the airports .bgl for Taxiway joints. Kind of like pieces of track a certain length to joints and planes have to stop at the nearest joint in relationship with user aircraft.

Actually this was done intentionally from the first FSX release. It was done because FS2004 had the opposite problem, AI aircraft running into your aircraft if you braked too fast. They got a little too cautious though in FSX.

Might i add this is the case with ALL AI traffic, 747s, A32Xs etc etc, so i believe this distance thing has something to do with the user aircraft?

 

As I've said: Open the user aircraft's exterior model in RADItor and check if the model radius and gbounding box values correspond to the dimensions of the real aircraft.

Bjoern, since you seem to KNOW where I am only guessing :huh: , could you enlighten me a little about the AI engine's operation in this regard?

 

I read elsewhere above (Cpt Spears' comment) that the AI engine will taxi aircraft up to the nearest joint in the taxi path which could potentially be much more widely spaced than the respective aircraft's radii. Is it the case that the AI engine will move its aircraft until the model radii of the leading and following aircraft touch? Is there fancy code in there to decelerate the AI aircraft as it gets closer?

 

Cheers,

 

Z

As I've said: Open the user aircraft's exterior model in RADItor and check if the model radius and gbounding box values correspond to the dimensions of the real aircraft.

That's not the issue, in fact I just checked the PMDG 737-800W and as an example UT2's 737-800 which I always see keeping it's distance in the sim, and the PMDG radius is 25.03m or 82.1 ft and the UT2 model is even smaller at 21.55m or 70.7 feet. The real aircraft is 129.6ft length. or 39.5m. So the size of the bounding box would not be the issue, If anything if the radius of the bounding box was what was calculated, the planes would be crashing into each other like what was the issue in FS2004. I remember Phil Taylor mentioning this early on, so they used a fixed value, that all aircraft would use to avoid this. I wouldn't be surprised though if it's a hidden variable that could be set that hasn't been discovered yet, like for example AI Taxi speed was, which some utilities can now set.

That's not the issue, in fact I just checked the PMDG 737-800W and as an example UT2's 737-800 which I always see keeping it's distance in the sim, and the PMDG radius is 25.03m or 82.1 ft and the UT2 model is even smaller at 21.55m or 70.7 feet. The real aircraft is 129.6ft length. or 39.5m. So the size of the bounding box would not be the issue, If anything if the radius of the bounding box was what was calculated, the planes would be crashing into each other like what was the issue in FS2004. I remember Phil Taylor mentioning this early on, so they used a fixed value, that all aircraft would use to avoid this. I wouldn't be surprised though if it's a hidden variable that could be set that hasn't been discovered yet, like for example AI Taxi speed was, which some utilities can now set.

 

Exactly!

Model radius:

I've had AI models taxiing all over the place because their model radius was set to 1.2km and the AI engine tried to avoid collisions with other AI aircraft at all cost. Hence my guess.

 

And Reggie confirms that this can be a cause for the issue:

http://www.flightsim.com/vbfs/showthread.php?210627-AI-Traffic-Taxi-Problem&p=1435827#post1435827

Model radius:

I've had AI models taxiing all over the place because their model radius was set to 1.2km and the AI engine tried to avoid collisions with other AI aircraft at all cost. Hence my guess.

 

And Reggie confirms that this can be a cause for the issue:

http://www.flightsim.com/vbfs/showthread.php?210627-AI-Traffic-Taxi-Problem&p=1435827#post1435827

 

Here is a quote from that post;

 

"Another possibility is that you have an addon 'AFCAD' type file in which someone has renamed and restructured the taxiway segments. When we 'clean up' Microsoft's taxiway segmentation, we destroy the AI taxi patterns. When we break the segmentation, we cause FS to think a taxiway is occupied when the aircraft is actually far, far away.

 

Unfortunately no one has yet figured out how to restore that segmentation with airport design tools. We really cannot even read the segmentation because it is the interaction of the airport file and the aiplayer.dll. We just know from repeatable experiments how to destroy it."

Here is a quote from that post;

 

"Another possibility is that you have an addon 'AFCAD' type file in which someone has renamed and restructured the taxiway segments. When we 'clean up' Microsoft's taxiway segmentation, we destroy the AI taxi patterns. When we break the segmentation, we cause FS to think a taxiway is occupied when the aircraft is actually far, far away.

 

Unfortunately no one has yet figured out how to restore that segmentation with airport design tools. We really cannot even read the segmentation because it is the interaction of the airport file and the aiplayer.dll. We just know from repeatable experiments how to destroy it."

This happens in default FSX airports with no third party AFCAD too, so I'm not convinced this is the issue either