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Patch: aircraft can use runways connected at ends to tayxiway

Started by Dwachs, August 03, 2011, 07:15:24 PM

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Dwachs

This should allow for more efficient airports. Also now a runway length of 3 tiles is enforced (can be relaxed though).
Parsley, sage, rosemary, and maggikraut.

prissi

However, this is forbidden in real life due to risk of plane not being able to take off when landing did not work out ...

Dwachs

Quote from: prissi on August 03, 2011, 08:50:53 PM
However, this is forbidden in real life due to risk of plane not being able to take off when landing did not work out ...
I do not understand.

Maybe I was not clear with the description of the patch: it allows to enter runways (for starting planes) directly at the end. And it allows landing airplanes to leave runway directly at the end. It is not longer necessary to drive back and forth on the runway.
Parsley, sage, rosemary, and maggikraut.

prissi

In real life runways are never connected straight to taxiways (witht he expections of very peculiar small airports in the end of a valley. There is always a 90° turn (or whatever angle) to be able to take off in two directions. Otherwise a runways would be useless for many wind directions.

See http://de.wikipedia.org/wiki/Start-_und_Landebahn#L.C3.A4nge_und_Breite in german wikipedia

Dwachs

Quote from: prissi on August 04, 2011, 07:54:20 PM
There is always a 90° turn (or whatever angle) to be able to take off in two directions. Otherwise a runways would be useless for many wind directions.
And exactly such a configuration will not work in simutrans. Dont know whether the patch changes this. 8)

The current implementation is not realistic either: aircraft enter the runway somewhere in the middle, drive to the end, turn, accelerate, take off. Entering the runway at the end is not allowed, see screenshot.

Edit: updated patch to handle airplanes that enter end of start runway from the side.
Parsley, sage, rosemary, and maggikraut.

prissi

Before the actual start/end of a runway there is the blast area, approaching lights, etc. in real life. To be able to have those as well as tire marks in simutrans, the runway were designed this way. Also the runway must start with the designation of the angle (which lacks in pak64, but is at least there in pak128). And if curves are allowed for runways, then very strange stuff can be built. I am not sure if not parts of this was saved in the german forum; but I fear most of this was just discussion with Hendrik (Siegelen) who made the first implementation of airplanes. Unfourtunately also the SVN of that time is lost, there had been more useful comments then.

Apart from these fundamental critics, your patch let to diagonal approach in a very short test for a curved runway end in est direction and planes coming from NE.

Ters

If the end tiles are meant to be blast areas, then maybe they should look and behave as such. That means no airplane movement on them at all. From what I have seen of runways, taxiways usually enter the runway closer to the ends than the touchdown zones.

In essence, a realistic runway would need at least three types of tiles: pre-tile with approach lights and/or blast area, end tile with end lights, threshold and first sign of tire marks, and middle tiles. Taxiways should connect to the last two types, while planes would first touch down at the first middle tile. Departing airplanes would enter the runway at the taxiway at the end, and arriving planes (not sure about this) would exit at the first taxiway it encounters after slowing down. A more complex runway would need apporach tile(s), blast tile, threshold tile, touchdown tile and middle tiles.

Implementing this without making runway contruction too complex and keeping things compatible with existing solution would likely be quite a tough challenge.

sdog

QuoteImplementing this without making runway contruction too complex and keeping things compatible with existing solution would likely be quite a tough challenge.
there are ways to make it easily understandable to the users. including some kind of markings, fences or other barriers in the graphics for the blast and approach tiles will immediately show players that they can't connect there. If treshold tile and middle tiles are only constructed if the runway has reached the minimum length, players will just increase it's length up to that length and connect a taxiway to the tiles allowing to do so.

Don't forget, it's already not self explanatory at all, since it is possible to connect runways in ways that won't let aeroplanes start or land. Finding out the reason why it doesn't work is quite hard for new players.

prissi

It is not possible to connect to runways on end tiles currently. You have actively remove end tiles to achieve that and end with a graphics that clearly indicate that something is broken. (Like in the screenshot above.)

And the planes touch down in the middle of the first runway tile. The first half is something like a blast area. In such way the simutrans airports are somewhat inspired form the OpenTTD airports.

The purpose of Dwachs patch was to make things simplier, which would mean even less blast areas etc. But I just fear, that allowing curves on runways will rather invite building airports entirely out of runways ...

But it is good that more people comment on that.

Dwachs

It is possible to connect taxiways straight to runway at the end of runway without removing bits of the runway.

Moreover, airplanes can start for some of these configurations but not for all. The patch aimed to get some consistent behavior. Entering runways from the side is not the main purpose.
Parsley, sage, rosemary, and maggikraut.

prissi

Then the connection to the end is an error. It was not allowed way back, at least there where check to avoid that. Maybe this was broken somehow in between.

Ters

Is it possible to have planes land on the second tile, start taking off from the second tile, and only drive to the second last tile when landing? If one then connect taxiways to the second tile from either end, the planes would then just enter the runway, turn 90 degrees and take off. Same with landing, replacing the current 135+45 degree turns with a single 90 degree turn. The end tiles could then retain their unconnectability, and possibly have blast pad marking. Only problem would then be tiremarks, which should start gradually in the second tile, still requiring three tile images: end, touchdown and middle.

Colin

Quote from: Ters on August 06, 2011, 10:47:10 PM
Is it possible to have planes land on the second tile, start taking off from the second tile, and only drive to the second last tile when landing? If one then connect taxiways to the second tile from either end, the planes would then just enter the runway, turn 90 degrees and take off. Same with landing, replacing the current 135+45 degree turns with a single 90 degree turn. The end tiles could then retain their unconnectability, and possibly have blast pad marking. Only problem would then be tiremarks, which should start gradually in the second tile, still requiring three tile images: end, touchdown and middle.

Yes this works already but you must use the Entrance and Exit plus the way arrows on the taxiway.
I may not agree with what you say, but I will defend to the death your right to say it

Thought for the day

When you are up to your backside in alligators, it is difficult to remind yourself that your initial objective was to drain the swamp.

Ters

Quote from: Colin on August 07, 2011, 04:57:52 AM
Yes this works already but you must use the Entrance and Exit plus the way arrows on the taxiway.

That is how I build my airports, but as your screenshots show, planes still make unrealistic 135+45 degree turns, which is just marginally better than 180+90. The upper image shows a plane that has made a 45 degree right turn and that will soon turn 135 degrees to the left to take off. It would be more realistic, IMHO, if it just made a 90 degree turn (or 45+45) to the left when entering the runway. But that should position the plane at those white stripes currently located in the end tiles.

In the lower image, the plane has driven past the taxiway and made a 135 degree turn to the left to drive back to the taxiway. It should never have driven past it.

Vonjo

I'm sorry, back to the topic. I am not sure whether this is a good idea or not. This is just my idea.  ;D
Will it work?

http://simutrans-germany.com/files/upload/airport.png

Colin

Quote from: Ters on August 07, 2011, 08:29:14 AM

In the lower image, the plane has driven past the taxiway and made a 135 degree turn to the left to drive back to the taxiway. It should never have driven past it.

I dont quite understand your meaning with this one. My understanding is, when a plane lands it proceeds down the runway to the end, then it turns back and proceeds to the taxiway and on to the terminal. The main problem I have with planes is, because of the run off at the end of the runway, no matter how small, it causes an approaching plane to go into a circular orbit. I asked, many moons ago, if there were some way in which planes could choose alternate runways, just like trains choose platforms, but it seems the answer is no, and the solution is to alocate runways as waypoints, but that can get extremely complicated when one has hundreds of planes in the air. What we need is an automated Traffic Controler. ;D
I may not agree with what you say, but I will defend to the death your right to say it

Thought for the day

When you are up to your backside in alligators, it is difficult to remind yourself that your initial objective was to drain the swamp.

Colin

Quote from: Vonjo on August 07, 2011, 10:34:41 AM
I'm sorry, back to the topic. I am not sure whether this is a good idea or not. This is just my idea.  ;D
Will it work?

http://simutrans-germany.com/files/upload/airport.png

Hi Ters, Try doing that with 25 planes trying to land you'd run out of map room. :D
I may not agree with what you say, but I will defend to the death your right to say it

Thought for the day

When you are up to your backside in alligators, it is difficult to remind yourself that your initial objective was to drain the swamp.

Dwachs

Quote from: prissi on August 06, 2011, 10:03:37 PM
Then the connection to the end is an error. It was not allowed way back, at least there where check to avoid that. Maybe this was broken somehow in between.
See attachment. Airplanes take off at a runway if the north/west end is not connected to anything else. However, after map rotation this does not work no longer... That is, whether airplanes find a route or not depends on map rotation :P

The patch should change this. Moreover, the airport with two runways (airport1.png) will work as expected: planes will use the western runway for landing, and the east one for take off.
Parsley, sage, rosemary, and maggikraut.

prissi

But all of those are airport designs strictly forbidden in reality, since an overshooting plane will crash into the landing site ...

Anyhow, with your patch try the attached savegame. With this it does not use the runway at all un the lower left airport but touch down diagonally.

Dwachs

UPdated the patch, this is working now.
Parsley, sage, rosemary, and maggikraut.