[RFD] Tunnels (what is a tunnel?)

[Zuu]

ON TOPIC ONLY
I wrote in my comments list:

* Tracks:Tunnels: To get tunnels right we need to take some time for thinking, and discussing.

The FRD wrote:

Tunnels

A tunnel is an pathway through hills or mountains, either above or below sealevel. Tunnels can also be drilled under a river or a lake. In this pathway tracks of any kind may be layed. The price of a tunnel is determined by the amount of substance above it and the matterial through which it must go. Sand would be the cheapest and rock and water the most expensive. Tunnels can be sloped, maybe even curved.

Optional features:

• Vacuum tunnels for maglev trains. Trains inside the tunnel can go faster than a bullet, since there is no air resistance, or friction. Vacuum tunnels should cost a lot of money.

The FRD writes that a tunnel is a object(not abstract) that you can create, that begins somewere and ends somewere else. It can go under land and water. Maybe you can think of this object as a "track" which you can build other tracks inside.

In Chris Sawyers games TT and TTD tunnels just have an entrance and a an exit. The track between that the player thinks that the train drives on does not 'exist'. In RCT1, RCT2 and Loco the track exist between the entrance and the exit. But there is no such thing as a tunnel without a track inside. Ie there is no tunnels. Tracks are just allowed to go under and above land.

I havn't seen any game or simulator that have real tunnels, that can exist without a track inside. If we are going to have that. How shall dhey be created by the user? As a 'track' or land modification? If its not a track, have we any idea how to make it work? How can a user tell that I want to dig a 2x8x2 cubes big cave 18 meters under this city, at X,Y? SO that he can place a station there.

I know that users want good tunnels. But does there exist a good way to make tunnels? Maybe we have to seperate that a bit. Seperate tunnels from underground. Tunnels just need an entrance and an exit, but constructing coplicated undergrounds need A LOT more.

I feal that I can write a lot more, but I stop here, and listen to what you have to say.

[Hellfire]

I'm wondering... What use would a tunnel have if there is nothing inside it?

[PJayTycy]

I am used to looking at tunnels the way RCT does it : it's just track below ground level, so the drawing is changed a little (a concrete "tunnel" instead of track). Some things that follow from this approach:

=> Collision detection needs to be 3D instead of 2D (so you can build track above and under houses/water/other tracks)
=> Nothing special needs to be done to support turns and signalling etc...
=> An "inside" view should be accesible for the player so he can see what happens really.

Now, the last thing you mentioned is an interesting thing:

How will the user have control over tunnels? How to choose between a track following the ground and a track going underground? I certainly feel the need for user-control here. Game AI can provide nice proposals based on some settings, but they will never be exactly what you want. So, if tunnels are just track underground and bridges are just track above ground, the question becomes : how to set the height of a track? The problem is, I don't have an answer to that question.

Your other problem, how to put stations (and, in general: buildings) underground (subway) and in the air (eg busstations on a bridge) is a different thing... Maybe we should have 2 categories of buildings, those that can only be built on the ground and those that can be built at any height. For the last category, a player would define a spot on the ground with the first click, move the building up/down with his mouse and define the height with the second click.

[Zuu]

Answer to Hellfire:

Well, in TTD I used tunnels infront of bridges becuse
* eaven best bridge is slowing down my fast trains.
* they look better than bridges in the landscape

[Hyronymus]

But then they had tracks in them, right? Hellfire wants to know what would be the use of a tunnel without (rail)roads in it.

[Zuu]

But then they had tracks in them, right? Hellfire wants to know what would be the use of a tunnel without (rail)roads in it.

Oh, there I see. I was thinking that the tunnels in TTD had nothing inside. (Which they don't. But users are fooled to beleve that.)

Well, use for an empty tunnel? Place stuff inside. Honestly, I cant think out any good resons for things that you cant do with tracks. Like a canal tunnel, or a tunnel throght a high and wide mountain for airplanes.

How will the user have control over tunnels? How to choose between a track following the ground and a track going underground? I certainly feel the need for user-control here. Game AI can provide nice proposals based on some settings, but they will never be exactly what you want. So, if tunnels are just track underground and bridges are just track above ground, the question becomes : how to set the height of a track? The problem is, I don't have an answer to that question. Confused

Your other problem, how to put stations (and, in general: buildings) underground (subway) and in the air (eg busstations on a bridge) is a different thing... Maybe we should have 2 categories of buildings, those that can only be built on the ground and those that can be built at any height. For the last category, a player would define a spot on the ground with the first click, move the building up/down with his mouse and define the height with the second click.

What about this: You select a track/building or anything that can be placed in 3D. By moving the mouse you select the X,Y cordinates. Then Press shift, and move your mouse to selsect Z cordinate, and click to build.

No need for special buildings for placement in 3D.

[Hellfire]

Ihow to set the height of a track? The problem is, I don't have an answer to that question.

How about the Locomotion/Rollercoaster tycoon way? That works reasonably well.

[uzurpator]

Well - Methinks that tunnels (and elevations - eg 'negative' tunnels) should be built as a product of auto-landscaping. When an earth cut cannot be made a tunnel will start.

As for viewing - it would suffice to allow the player to "remove" all objects that are above certain height.

[PJayTycy]

Ihow to set the height of a track? The problem is, I don't have an answer to that question.

How about the Locomotion/Rollercoaster tycoon way? That works reasonably well.

That works only for placing track one piece at a time.

The 3DTT (and TTT) method could work, but is a lilttle limited : you define starting and ending height, all track has a constant slope between those points (creating cuttings/tunnels/bridges where needed).

[Zuu]

I don't think that there is one tool that gives users control of everything, that is efficent to use. I think it would be good if we can give users several tools that can be used for diffrent kind of track laying.

• A TT(D) like click and drag tool
• A RCT/Loco like tool. Select start pooint, and build from that point using a control
  window.
• Any more good tools?

But now we are more on user interface stuff.

[Hellfire]

How would you do it in your 360 degrees track laying prototype?

[PJayTycy]

How would you do it in your 360 degrees track laying prototype?

Possible options:

• 1 piece at a time :
  • RCT-like control window
  • TTD-like : normal track always follow ground level. If you want a tunnel/bridge, you click some button and switch to RCT-like building. TTD-style is impossible for tunnels/bridges.
• 1 long section at a time:
  • 3DTT = TTT style : define height at start and stop (by holding CTRL), all pieces have the same slope between them.
  • RT3-like : track follows the ground up to a certain max. slope, if the slope is steeper, it is automatically changed to tunnel/bridge. I don't like this because you don't have enough control, but it can be used as an initial "proposal" that the player can modify. (ie: select 2 points => use 3DTT style between them : transform track to a constant slope, automatily create cuttings/tunnels/bridges)

[ChrisCF]

Perhaps it might be better if we treated all tracks as "tunnels", with their bounding boxes determining the loading gauge. When you bore a tunnel, it has to be big enough for everything of the required loading gauge to get through. When you build one track over another, the same principle applies. So for all intents and purposes, tunnels exist just like any other piece of track, road, etc. As for buildings being elevated or sunk, remember that for the most part, stuff needs to be able to get in and out, rather than just looking like they have to magically teleport their way out. As for whether it can go on an elevated track, all you need to do is have a property for each building that specifies whether or not it needs firm foundations. If it does, then you can't put it on an elevated track. For underground constructs, you only decide whether or not your structure has a roof (since you don't need one underground). This way, roofless structures that don't need firm foundations can go over, at or under the ground level, whereas roofed buildings that do need foundations have to go at ground level.

[Steve]

Agreeing with Chris, tracks in tunnels should be no different from normal tracks in the style that they are built or the features that they can possess. As long as it's easy to make sure tracks don't go underground if you don't want them to, or you'll be wasting money on moving that dirt. Using the 360 degree prototype, i suggested blocks of track. One block leading to a tunnel and then the next block(s) would be underground before stopping as it leads to the service. Then you have clear indications of where normal track ends and a tunnel begins.

Lets not forget that tunnels are very expensive and could possibly take extra time to build?

Vacuum tunnels: How do you get out into a air environment, in order to let people on? Space age force fields with hold out the air? Air tight locks that surround the train at stations?

[Hellfire]

Vacuum tunnels: How do you get out into a air environment, in order to let people on? Space age force fields with hold out the air? Air tight locks that surround the train at stations?

Maybe something like in the attached image.

A station has an vacuum area where the train stops for boarding. This area is sealed off from the tunnels by the station doors (in red). People get on and off the train through the air locks (in gray). The train is constantly in a vacuum area, but the station doors guarantee that the tunnels do not get compressed when the airlocks fail.

[Hyronymus]

Then you need a second set of doors to decompress people (Winzip gate?). That would create some queues!

[jfs]

Another idea for handling tunnels and bridges:

Each map square has a number of landscape surfaces and landscape roofs. Always at least one surface (the ground.)
Structures can only be built directly on top of a landscape surface. Every structure has a height. There has to be enough space between a landscape surface and the next landscape roof/surface to account for the entire height of a structure built on the surface.

This is of course entirely internal to the game. When the user builds a tunnel, s/he is in fact adding a new landscape surface and roof below the original landscape surface, and probably also filling out the new room that's been made.

Bridges would be similar, except that it just adds a new landscape surface (including decoration) above ground level. Some but not all bridges might have landscape roofs over them.


One reason to have a tunnel without anything inside it, or a bridge with nothing on top, would be if you were replacing track, or maybe prepare for building a route later on.
You could eg. pull up an old road inside a tunnel, leave the tunnel, and 5 years later build a new railway inside the tunnel. Or as zuu suggested (a bit jokingly?) make a huge tunnel for airplanes or ships.

Also: Underwater tunnels don't have to be underground as well. An underwater tunnel could just as well just be a concrete tube laid on the ocean floor, or whereever it's built.

[Zuu]

jfs: Are you a mind reader? That was exactly the same idea I got last night.

[Hyronymus]

I think that's the best approach to it but let's suggest we want a graded tunnel. Is that as possible as graded track?

[Steve]

Graded?