Doom secret place tip
Dwain Dibbly
even with the map to show you which walls are possibles,
then try this.
When you click on a wall to open it, if it doesn't make a sound
then shoot it.
This tip courtesy of Chris Attewell, Brighton Uni.
Don't play the game on anything less than difficulty level 3. Far
too easy (unless you're on a 386, then the left-right aiming can be hard!)
The last 'level' shouldn't have an invisibility thingy on it. Makes it a
walkover. Just launch 10 rockets at the 'goatmen' and they're history.
The real interest lies in the network game. Then things really get fun.
Its a pity that when you punch your mate, they see it as if you fired a gun
at them.
Anyone noticed how the game isn't really multi-level? You never actually
stand above/below another point that you could be at. This makes the mapping
easier I suppose...
There is also the problem of people shooting you when you stand at the edge
of something. You can't look down, so you can't see whos getting you.
The chainsaw is very good. I like the way the walls can be 'smoked'
I would've liked to be able to hit people with the stock of my shotgun
once it's ammo had run out.
Outa here...
Hunting the Snark
In article <1993Dec13.1...@unix.brighton.ac.uk>, h...@unix.brighton.ac.uk (Dwain Dibbly) writes...
>Anyone noticed how the game isn't really multi-level? You never actually
>stand above/below another point that you could be at. This makes the mapping
>easier I suppose...
Wrong, there are definitely tunnels and bridges. The is a tunnel to the outside
on the first level, for example.
Sm
Seth Cohn
BZZZT! Sorry, but thanks for playing. Here's a home edition of Doom for you
to enjoy. NOWHERE does the game has spots when someone is directly over you
(or under you) ie: this: X but never this : X
=| =
|X X
Kudos to id though, best 2D mapping I've seen. I want SPECS, cause I
want an EDITOR!
Seth
--
Seth Cohn - Warning - I use CAPS to emphasize, not to yell |If you read
email preferred - I consider spelling errors and grammar |RUOW, Honk!
Net Junkie since 89 to be secondary to the meaning itself |Orange Rainbow
[Space for rent] - I take unpopular positions & get flamed|Spirits R #1!
Doug DeJulio
Dwain Dibbly <h...@unix.brighton.ac.uk> wrote:
>Anyone noticed how the game isn't really multi-level? You never actually
>stand above/below another point that you could be at. This makes the mapping
>easier I suppose...
Yes, you CAN go above/below points you can get to. One example I can
think of is the tunnel that goes under the ground outdoors, that leads
to that little shed that lets you go outside. There are others.
--
Doug DeJulio
dd...@cmu.edu
Jim Little
you to have bridges, etc. So it was actually possible to stand on the same
x, y coordinates, but different z coordinates. In doom, every x, y pair has
a specific z coordinate. There are no bridges (per se) and no tunnels -that
you can walk over-. It's shortcuts like this that make the game run faster.
There's some other neat shortcuts they used as well... not being able to look
up or down, and having the player's light light a cubical rather than spherical
area. The lighting was pretty impressive, too; they made each section have
it's own (possibly fluctuating) brightness, but there is no actual 'light
sourcing' with real-time calculations for areas of dark and light. (I imagine
when the map editors come out these areas will have to be entered manually
to achieve realistic lighting effects.)
All these short-cuts contribute to an incredibly fast game that sacrifices
only the parts that don't matter in an action game. Id did an incredible
design for this game, deciding exactly what tradeoffs should be made. For
those that are still upset about wall marking, etc., remember that they did
put a -lot- of thought into it.
Anyway, enough tirading.. the above are opinions only -- guesses I've made
by watching the game. Believe at your own risk. :)
-Jim Little (ji...@up.edu)
Cheng-Jih Chen
>then shoot it.
>This tip courtesy of Chris Attewell, Brighton Uni.
Actually, this works but there should be a minor caveat: if you're
pushing a wall that happens to be underneath a platform, it won't make
a sound either. Has something to do with the fact that DOOM isn't
multilevel: walls make sounds if they're "walls" in some sense, and
not doors or raised pathways.
Ben Aaron Rudiak-Gould
>>In article <1993Dec13.1...@unix.brighton.ac.uk>,
>>Dwain Dibbly <h...@unix.brighton.ac.uk> wrote:
>>>Anyone noticed how the game isn't really multi-level? You never actually
>>>stand above/below another point that you could be at. This makes the mapping
>>>easier I suppose...
Yes. Much, much easier. Trust me.
>There are no bridges (per se) and no tunnels -that
>you can walk over-. It's shortcuts like this that make the game run faster.
>There's some other neat shortcuts they used as well... not being able to look
>up or down, and having the player's light light a cubical rather than spherical
>area.
Not exactly. (See below.)
>The lighting was pretty impressive, too; they made each section have
>it's own (possibly fluctuating) brightness, but there is no actual 'light
>sourcing' with real-time calculations for areas of dark and light. (I imagine
>when the map editors come out these areas will have to be entered manually
>to achieve realistic lighting effects.)
Yes.
>All these short-cuts contribute to an incredibly fast game that sacrifices
>only the parts that don't matter in an action game. Id did an incredible
>design for this game, deciding exactly what tradeoffs should be made.
You seem to be proceeding from the assumption that the DOOM graphic engine
uses an algorithm similar to the UW graphic engine. This is *completely*
untrue. UW actually decomposes the level into polygons using some sort of
extremely fast clipping routine, sorts them back-to-front, projects them
into 2-D, and perspective-maps them to the screen. DOOM merely uses an
extended version of the Wolf3d algorithm, which is fast but not very
versatile. The DOOM algorithm *cannot* be extended to allow for looking
up and down, spherical light falloff, sloping floors, bridges, etc. So id
did sacrifice versatility to speed, but not in quite the way you suggest.
--
Ben Rudiak-Gould
be...@uclink.berkeley.edu
"'Tis a long way further than Knighton,
A quieter place than Clun,
Where DOOMsday may thunder and lighten,
And little 'twill matter to one."
-- A. E. Housman
Russell Webb
Ben Aaron Rudiak-Gould <be...@uclink.berkeley.edu> wrote:
>The DOOM algorithm *cannot* be extended to allow for looking
>up and down, spherical light falloff, sloping floors, bridges, etc. So id
>did sacrifice versatility to speed, but not in quite the way you suggest.
I'd seen indications from id that ramps/sloping floors would likely
be present in the commercial Doom engine next year. What changes and
ramifications would this have on the algorithms Doom uses?
-Russell Webb
rw...@panix.com
Seth Cohn
>
>>>
>>>>Anyone noticed how the game isn't really multi-level? You never actually
>>>>stand above/below another point that you could be at. This makes the mapping
>>>>easier I suppose...
>>>
>>>on the first level, for example.
>>>
>
>>BZZZT! Sorry, but thanks for playing. Here's a home edition of Doom for you
>>to enjoy. NOWHERE does the game has spots when someone is directly over you
>>(or under you) ie: this: X but never this : X
>> =| =
>> |X X
>
>and watched their guts fly out over the top of bad guys below.
>Sorry to be so anal but I really hate people who say "BZZZT! Sorry, but
>thanks for playing."
>
Excuse me but: BZZT, Sorry but thanks for playing. What you describe has
NOTHING to do with what I posted. If you can find a spot on Doom that
isn't 2-D mapped to 3-d by a varied Z height, I'll dance naked on Usenet.
This game is very nice, but it's NOT real 3-D, I can NEVER find a spot
where I am directly below another spot I could stand on. NO tunnels
exist that you can stand ON TOP OFF. Look at any map: there is NO spot
used twice (once above/below another)
Oh, and here's a home edition of Doom for you too.
Denis R. Papp
>dd...@cs.cmu.edu (Doug DeJulio) writes:
>>Yes, you CAN go above/below points you can get to. One example I can
>>think of is the tunnel that goes under the ground outdoors, that leads
>>to that little shed that lets you go outside. There are others.
>I'm fairly sure that you still never go under any place that you can walk.
>You can't go out ontop of where the tunnel was. (I'll have to check)
>But from the other perspective, you shoudn't be able to go under a place
>you have been unless you could see some "crossover" on the map.. and I have
>seen no such crossover.
Correct, I'm positive about this. In the example for going to that
shed, you actually go AROUND the ground area. You do not go under it.
It is not true multi-level (ie. you cannot be above/under another passage)
This fact is very important for the shooting bit too
--
Denis Papp _ __ _ dp...@cs.ualberta.ca
/_ /_/ /\/ /-/ / / /_ dp...@amisk.cs.ualberta.ca
"Man, that little bastard smells. No wonder they call him Pooh."
-- Christopher Robin
Denis R. Papp
>You seem to be proceeding from the assumption that the DOOM graphic engine
>uses an algorithm similar to the UW graphic engine. This is *completely*
>untrue. UW actually decomposes the level into polygons using some sort of
>extremely fast clipping routine, sorts them back-to-front, projects them
>into 2-D, and perspective-maps them to the screen. DOOM merely uses an
>extended version of the Wolf3d algorithm, which is fast but not very
>versatile. The DOOM algorithm *cannot* be extended to allow for looking
>up and down, spherical light falloff, sloping floors, bridges, etc. So id
>did sacrifice versatility to speed, but not in quite the way you suggest.
A definite plus in UW over doom. Would be nice to have true multi-level
indoom, there are times that I would find looking up/down very useful.
And what about jumping? Another great thing in UW
Jim Little
>>only the parts that don't matter in an action game. Id did an incredible
>>design for this game, deciding exactly what tradeoffs should be made.
>
>You seem to be proceeding from the assumption that the DOOM graphic engine
>uses an algorithm similar to the UW graphic engine. This is *completely*
>untrue. UW actually decomposes the level into polygons using some sort of
I knew that Id used a different type of engine than UW.. I wasn't sure of
the details. UW is very obviously a 3-D construct; given the data for each
level, you could build a model of each level. It seems that DOOM is a 2-D
game with varying z-values; given the data, you would have to tweak it
before you could build a model.
But, as I said, this is all speculation at best, from observations of the game.
It's fun to speculate, though... :) Actually, I think the map is stored as
a two-dimensional array, with two z-values for each (x,y) pair. The z-value
represents where the floor starts, and where the eiling starts. Of course,
there's other data, and perhaps some storing tricks, but that's what it looks
like to me. And although you're not 'actually' representing a 3-D space,
who can tell the difference? (One of my favorite programming maxims is,
"It doesn't matter -how- you achieve the result, as long as no-one can tell
it from the real thing." :) )
-Jim Little (ji...@up.edu)
(I just realized an error in my logic. If the map is a two-d array, how are
diagonal walls stored? I coulda sworn I saw an actual -curved- wall, as well.
Hmm..)
Denis R. Papp
>-Jim Little (ji...@up.edu)
>(I just realized an error in my logic. If the map is a two-d array, how are
> diagonal walls stored? I coulda sworn I saw an actual -curved- wall, as well.
> Hmm..)
None of the walls are *actually* curved. The best impression of curve comes
when they used real small rectangles (but not too smalt). I think you will
always be able to tell that they arent curved.
--
Denis Papp dp...@cs.ualberta.ca
dp...@amisk.cs.ualberta.ca
"Oh." -- Albert Einstein
Joshua Hughes
BZZT sorry..thanks for playing....
I agree that there is never a part in doom where you are standing directly
OVER another pathway. Over and to the side, yes...not directly over though.
However..i don't understand why you say the game is not true 3-d. Each
particular mission does have different height levels. (stairs,
elevators..etc..)
Each part of the map could be thought of as having a length, width, and
height.
Correct?
I'm out of home-edition dooms...here, have my old home edition of Wolf3d.
I'll never ever ever ever be using that again.
-Rufus
sl...@cc.usu.edu
>
> This fact is very important for the shooting bit too
Think about the reason why. Assuming they are still raycasting (like I do in
my Doom-style engine), they raycast on a totally 2-D area. The heights are
added afterwards.
Joshua JEnsen
Michael Hare
>From: se...@alchemy.TN.Cornell.EDU (Seth Cohn)
>Subject: Re: Doom secret place tip
>Date: 14 Dec 1993 22:40:44 GMT
>Anyone noticed how the game isn't really multi-level? You never actually
>stand above/below another point that you could be at. This makes the
>mapping>>>>>easier I suppose...
You are correct sir.. In a strict sense the game only has the _illusion_ of
3-D. But then, it only has the _illusion_ of being 2-D, or any thing else..
The floors could have been completely drawn on a single level (as in wolf).
The authors did not have to actually contend with a 3-D world (i.e. walking
over a place where you were before.) The illusion of going up and down is
merely an optical trick, but come on... It's really great, ain't it??
---
Michael Hare
OpenConnect Systems, Inc Main: (214) 484-5200 x475
2711 LBJ Frwy Ste 800 Fax: (214) 888-0686
Dallas, Texas 75234
Internet: m...@oc.com
Compuserve: 73422,2030
dod...@ac.dal.ca
paper, it can exist in doom, so this seems right) then that explains why:
a) you can't jump b) you can't look up or down (a shame, and something I wish
it had). It also makes Dooms "smart tracking" of where the enemy is
what angle of inclination you shoot, trivial. There is only 1 direction:
straight ahead. If an enemy is there, he falls.
But what about elevators? I realize floors don't overlap, even after you go
down an elevator, but the lift itself is "multi-level" (but only 1 level at
a given time, so I guess it's OK)
--
___________________________________________________________________
| Bruce Dodson || "Adam |
| Dalhousie University || Had'em." |
| dod...@ac.dal.ca || (On the antiquity of microbes) |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Seth Cohn
>However..i don't understand why you say the game is not true 3-d. Each
>particular mission does have different height levels. (stairs,
>elevators..etc..)
>Each part of the map could be thought of as having a length, width, and
>height.
>
>Correct?
>
No, True 3-d could contain 2 (or more) places wit hthe same x-y coords,
but Doom doesn't. It's got 1 XY position for each map spot with a
varied Z (height) to make it 3-dish... Note that the game WORKS, which is the
most important factor, and there are many tweaks to the varied Z height
which define things like overhang, underhang, and so forth. I'll
bet most of the map builders out there will use the tweaks to make
game that look even more 3d... but id did a GREAT job...
Joshua Daniel Grossman
[edited comments from everyone else]
I'm not sure how you all would like to define 2d vs 3d, but here's some
thoughts:
- you shoot straight ahead and hit an enemy at raised height, ONLY
IF THERE IS AN ENEMY TO HIT. Otherwise, it hits at your level. Even if there
is an enemy you miss, you fire at his height.
- Example of one point where you stand in a position directly atop
an old position: elevators, rising pillars, etc.
- Why not have other overlaps? Without knowing anything about Id's
graphics engine or the ideosyncracies of the game, the mapping feature
would cease be practically viewable (except in a mobile 3d interface -
anyone around here want to code that one?).
- Why no one needs to look up in the current design: You're at the
bottom of the screen. You have a clear view of what is above you. In
contrast, begin at the bottom, you can't seen down in the same way. Realism
would be lost by placing the character centered on the screen - not to
mention that you'd probably then need to be able to look up _and_ down.
I think adding a look down, or aim high/low feature would be nice, but
a players ability to control this is dubious.
That's all for now folks....
Seth Cohn
>>Well if the game really _is_ just one level (Jay said if you can draw it on
>>paper, it can exist in doom, so this seems right) then that explains why:
>>a) you can't jump b) you can't look up or down (a shame, and something I wish
>>it had). It also makes Dooms "smart tracking" of where the enemy is
>>what angle of inclination you shoot, trivial. There is only 1 direction:
>>straight ahead. If an enemy is there, he falls.
>>
>>But what about elevators? I realize floors don't overlap, even after you go
>>down an elevator, but the lift itself is "multi-level" (but only 1 level at
>>a given time, so I guess it's OK)
It's a varied Z height which is fine, but ONLY 1 Z at a time... same for
stairs which rise up when triggered...
>I'm not sure how you all would like to define 2d vs 3d, but here's some
>thoughts:
> - you shoot straight ahead and hit an enemy at raised height, ONLY
>IF THERE IS AN ENEMY TO HIT. Otherwise, it hits at your level. Even if there
>is an enemy you miss, you fire at his height.
The game only take Z into account if an enemy is is within the right XY
space. Same a lot of time in figuring stuff. Try it with the rocket launcher
and you'll either hit something or it'll be level with you.
> - Example of one point where you stand in a position directly atop
>an old position: elevators, rising pillars, etc.
Yes, but again, you can't have 2 XY the same and different Z AT THE SAME TIME.
> - Why not have other overlaps? Without knowing anything about Id's
>graphics engine or the ideosyncracies of the game, the mapping feature
>would cease be practically viewable (except in a mobile 3d interface -
>anyone around here want to code that one?).
The game engine won't DO it. It's the only way to make it look 3D without
real 3D. It's called making it WORK, ratherthen making it 3D. 2D with
varied Z height is easy to calc (much faster) and looks 90% as good.
The only thing you CAn't DO it is make a bridge with people above and below
it. I don't really care about that though.., since it's a minor thing.
> - Why no one needs to look up in the current design: You're at the
>bottom of the screen. You have a clear view of what is above you. In
>contrast, begin at the bottom, you can't seen down in the same way. Realism
>would be lost by placing the character centered on the screen - not to
>mention that you'd probably then need to be able to look up _and_ down.
>I think adding a look down, or aim high/low feature would be nice, but
>a players ability to control this is dubious.
Game engine won't do it though.
sl...@cc.usu.edu
> paper, it can exist in doom, so this seems right) then that explains why:
> a) you can't jump b) you can't look up or down (a shame, and something I wish
Ah, but you COULD jump if they wanted to make you jump... they just didn't
allow it. all that needs be done is modifying the player's Z coordinate. You
CAN'T look up or down though... :)
> But what about elevators? I realize floors don't overlap, even after you go
> down an elevator, but the lift itself is "multi-level" (but only 1 level at
> a given time, so I guess it's OK)
All elevators do is change your Z position... they are a moving floor, so the
elevator's Z position changes too... if you were to see the place where the
floor for the elevator was moved from, you'd probably see the engine do strange
things to the screen! :)
Joshua Jensen
Jim Little
>> game with varying z-values; given the data, you would have to tweak it
>> before you could build a model.
>>
>> a two-dimensional array, with two z-values for each (x,y) pair. The z-value
>> represents where the floor starts, and where the eiling starts. Of course,
>Well if the game really _is_ just one level (Jay said if you can draw it on
>paper, it can exist in doom, so this seems right) then that explains why:
>a) you can't jump b) you can't look up or down (a shame, and something I wish
>it had). It also makes Dooms "smart tracking" of where the enemy is
>what angle of inclination you shoot, trivial. There is only 1 direction:
>straight ahead. If an enemy is there, he falls.
>
>But what about elevators? I realize floors don't overlap, even after you go
>down an elevator, but the lift itself is "multi-level" (but only 1 level at
>a given time, so I guess it's OK)
Elevators? Simple. Just continuously increment the z-value representing the
floor. Also, I was playing a multi-player game (my God, is that fun!), and
I attempted to jump down on top of somebody's head. Interestingly enough,
the way was blocked.. just like when you try to walk around a barrel. I slid
until I was standing next to the character, then fell to the floor beside him.
This seems to bear out the 2-D theory. --And I can see how that would make
rending much faster and easier.
NOW.. my programming wisdom will be made available for all to partake..
(Big grin.) -If- all my theories are correct, Id can easily update the engine
to allow for bridges and overhangs. What they would need to do is store
-four- z values for each (x,y) pair. z1 and z2 represent the floor and
ceiling of the lower level; z3 and z4 the floor and ceiling of the upper
level. Which level someone is standing on could be kept track of with a
single bit.
Okay, it's kinda kludgey, but it might work, while still allowing decent
speed. The rendering engine would have to be reworked, and keeping track of
where a player was standing might require a little work. ... Hmm ... it
might actually work... ... hm..
Oh, sorry, back to reality. Well, that's my thought for the day.
-Jim Little (ji...@up.edu)
Tacettin Koprulu
Yes, you are right, they don't use classical light source calculations,
that's why you don't see any shadows in the game. But, I think that
would add a new realism to the game. Imagine when you see a huge
shadow on the wall suddenly.
Another idea could be mirrors or shiny reflections, which I could see
myself.
And the most important thing is that the game is not fair in terms
of the arms the others have. Why can I have chaingun, but not the
others. You would say in that case the game would be nearly impossible
to finish. I would say decrease the number of enemies and create more
intelligent ones. I don't see any collobaration when 10 of them
come to me like sacrifices ready to be blown up immediately.
I remember an old game which was "Spy vs. Spy" inspired from cartoons.
In that game you were preparing traps for your opponent. Doom is
visually stunning, but it is boring. I think it is time for ID to
put some interesting features to the game besides its graphics engine
so that it won't be one-night stand game.
Regards, Taci
with less powerful
Robert W. Igo
*is* multi-level. dod...@ac.dal.ca (2702)
>
> Well if the game really _is_ just one level (Jay said if you can draw it on
> paper, it can exist in doom, so this seems right) then that explains why:
> a) you can't jump
Define exactly what you mean here. You can certainly fall; jumping is
just the reverse of that, isn't it?
> b) you can't look up or down (a shame, and something I wish
> it had). It also makes Dooms "smart tracking" of where the enemy is
> what angle of inclination you shoot, trivial. There is only 1 direction:
> straight ahead. If an enemy is there, he falls.
> But what about elevators? I realize floors don't overlap, even after you go
> down an elevator, but the lift itself is "multi-level" (but only 1 level at
> a given time, so I guess it's OK)
The map (accessed with TAB) is 2-d and is often confusing since it
places the entire level in 2 dimensions, and it's often unclear by
looking at the map whether or there is a passageway in front of you or a
wall.
Sure, maybe Ultima Underworld was cool for some people, and it was
"real" 3d, but for now, bitmap scaling is doing a pretty good job.
[********************************* Bob Igo ********************************]
"What's up, is I finally got a career goin for myself. See that big rig?
I'm drivin it!" --local trucking school commercial
[***************************** gryp...@cmu.edu ***************************]
Mark S. Wyman
>Excerpts from netnews.comp.sys.ibm.pc.games.action: 15-Dec-93 Re: Doom
>*is* multi-level. dod...@ac.dal.ca (2702)
>>
>> Well if the game really _is_ just one level (Jay said if you can draw it on
>> paper, it can exist in doom, so this seems right) then that explains why:
>> a) you can't jump
>Define exactly what you mean here. You can certainly fall; jumping is
>just the reverse of that, isn't it?
>> b) you can't look up or down (a shame, and something I wish
>> it had). It also makes Dooms "smart tracking" of where the enemy is
>> what angle of inclination you shoot, trivial. There is only 1 direction:
>> straight ahead. If an enemy is there, he falls.
>> But what about elevators? I realize floors don't overlap, even after you go
>> down an elevator, but the lift itself is "multi-level" (but only 1 level at
>> a given time, so I guess it's OK)
>The map (accessed with TAB) is 2-d and is often confusing since it
>places the entire level in 2 dimensions, and it's often unclear by
>looking at the map whether or there is a passageway in front of you or a
>wall.
>Sure, maybe Ultima Underworld was cool for some people, and it was
>"real" 3d, but for now, bitmap scaling is doing a pretty good job.
UW was not "real" 3d. Bridges were the only the thing that were
actually 3dish (i.e. you could walk under them as well as on them).
UW did not have anything like rooms ontop of rooms. Besides bridges
UW and Doom use the same type of mapping (i.e. each coordinate has
only one z component.
Mark
Steven Berry
critters. Does this imply the potential for multi-level in the engine
and it was just left out?
Stevo
Lima Bone
Excuse me....but are you guys thinking about all this while you are playing?
I am so busy sneaking around corners scared out my wits that one of those
pink bastards is gonna tear my intestines out before I can pump about 50
shotgun shells into his head!!!!
Denis R. Papp
>In that game you were preparing traps for your opponent. Doom is
>visually stunning, but it is boring. I think it is time for ID to
>put some interesting features to the game besides its graphics engine
>so that it won't be one-night stand game.
There, this is a good idea. Right now you dont have all that much
for setting traps for your opponents, other than sticking around
yourself waiting for them to show up. Or waiting watching an entry to
the room witha barrel beside it.
IT would be better if you could move the barrels.
--
Denis Papp dp...@cs.ualberta.ca
dp...@amisk.cs.ualberta.ca
James Klinge
>In article <2eigop$m...@nntpd.lkg.dec.com> mars...@tfh.enet.dec.com (Hunting the Snark) writes:
>>
>>In article <1993Dec13.1...@unix.brighton.ac.uk>, h...@unix.brighton.ac.uk (Dwain Dibbly) writes...
>>>Anyone noticed how the game isn't really multi-level? You never actually
>>>stand above/below another point that you could be at. This makes the mapping
>>>easier I suppose...
>>
>>Wrong, there are definitely tunnels and bridges. The is a tunnel to the outside