[Vanilla Level Editing] Lesson 8: Remote-Control Sectors

[Linguica]

ADDING A SHOT-ACTIVATED DOOR

The final new door in this Sortie is to be an impact-activated door, located at the end of the passageway at the bottom of the stairs leading from the platform room — that should wake up those monsters lurking in the room behind the player! The following shows the extra lines that are needed to implement the new sectors. These will provide the door and a further room beyond it.



The settings for the new sectors are given in the following table. Don’t forget to check the special characteristic setting here, as these sectors are likely to inherit one from nearby.



Use PIPE2 on all of the new lines, but use PIPE4 on the face of the new door. It will be needed on both the upper and lower texture slots here, because the door sector’s floor is at a different height from the floor of the end of the passage.

Change the texture on the end wall of the original corridor to PIPE4, too. This is a shot-up version of PIPE2 and is to be used in this area as a visual clue to the presence of the door and the nature of its activation mechanism. Using it on a wall alongside the real door makes the texture’s presence more conspicuous but stops it from being immediately obvious which of the walls hides the door.

Don’t bother aligning the texture on the door face here. There is absolutely no need to line up the bullet holes on the two wall sections, and the other adjacent wall has a different texture anyway. Put whatever you fancy on the inner face of this door, bearing in mind that only its lower four pixels are ever likely to be seen.

Hide the door on the auto-map by setting the Secret on map flag of the appropriate line. As usual, make sure that the faces of the door have their right sides facing out from the door sector. Then use special type 46 (GR Door Open Stay) on the outer door-face, explicitly tagged to the door sector.

The rear face of this door doesn’t need any trigger mechanism, because the door will latch open. Don’t forget, though, to set the lower unpegged flag of the door sector’s side lines. Their textures can be left as PIPE2.

Finally, save your WAD (as D2WAD16.WAD to stay in step with my numbering) and try out your latest additions.

[Linguica]

LIGHT SWITCHES

Having seen how the remotely triggered mechanism can be applied to an action with which you are familiar — the door — we can now move on and look at other types of triggered actions. The first of these is the simple alteration of sector lighting levels through the use of brightness-level switches.

[Linguica]

BRIGHTNESS-LEVEL SWITCHES

DOOM does not provide many options for player-triggered light-level changes. The new settings brought about by the light level change actions replace the specified sector-brightness values, which are lost forever. Once it is changed through these actions, there is no way to restore a sector’s original brightness setting, except by having an adjacent sector to act as a copy of it (as will be demonstrated in the next WAD Sortie).

[Linguica]

AUTOMATIC LIGHTING VARIATIONS

It is possible to build areas that have the lights switch on as players move into them and switch off again as they leave (or vice versa). All that is required is a careful arrangement of retriggering lines. Such features are also good for multiplayer games, because it is possible for players to turn the lights out on their opponents, in order to give themselves the advantage. The next WAD Sortie demonstrates part of the necessary arrangement of lines. You may wish to experiment further with it yourself after completing your next WAD.

[Linguica]

WAD SORTIE 17: TRIPPING THE LIGHTS— FANTASTIC!

This Sortie will explore just one possible arrangement of switched lights. The area in which this will be used will be developed in later Sorties into a confusing maze area. These areas generally take a lot of time (and patience) to develop correctly. They can be a severe test of both the designer and the WAD editor. My advice is that you work on these areas in stages, perfecting each aspect of them in turn. Let’s start here by looking at the thinking behind the lighting design.

[Linguica]

SWITCHED LIGHTS: THE THEORY

The following shows a schematic arrangement for the lighting “tricks” that are to be played in the principal maze sectors.



The maze comprises three main areas:

• An entrance corridor
  
• A left part
  
• A right part
  

The complexity of the maze shape has been omitted from the figure so that you can better see and understand the scheme.

Each of these areas is rigged to have the lighting change as the player moves around. The effects are intended to operate as follows:

• The first time that the player enters the entrance corridor,the lights of this corridor will go out. Switch line A is the trigger for this. The lights will remain on in the rest of the maze. The lights to this corridor can only be turned back on by locating the appropriate switch (line B). Once the lights have been turned back on with this trigger, they will stay on.
  
• As the player enters the left part of the maze, its lights will go out. This is achieved by switch line C. Switch line D turns the lights back on when the player leaves this section of the maze. This happens each time the player passes over these lines. Notice how this arrangement has to differ from real light switches, because of the nature of DOOM’s line actions. As each line can only perform one function, two lines are needed if the lights are to be turned both on and off. Furthermore, both lines are retrigger lines. Each will attempt to carry out its action every time the player crosses it, regardless of the current light settings. The arrangement of these lines is therefore critical. The lights in this part of the maze will always be in whatever state the last line-crossing left them in. When entering, the off-switch is the last triggered; when leaving, the on-switch has the final say.
  
• The right part of the maze is rigged in the same way as the left, through switch lines E and F. These operate in exactly the same way as C and D, respectively, but they act on the right part of the maze.
  
• The right and left parts of the maze are linked through another line G. This line is an ordinary, inactive line. To explore the right part of the maze with the benefit of the lights, then, the player should enter the left part first but pass into the right section through this line. Leaving the maze by reversing this route will turn the lights back on in the left part, allowing that side to be explored with the lights on after re-entering it through line G from the right. However, if this area is constructed carefully enough, it could be quite a while before this tactic presents itself to the player.
  

[Linguica]

BUILDING IT IN PRACTICE

The following shows how the preceding idea has been implemented in my D2WAD17.WAD. The left part of the maze has been made a little more mazelike, and one or two details have been reworked slightly, but the three major divisions outlined in the preceding scheme should still be discernible. The locations of the seven lines that function as the lines A to G are marked.



You may like to start DOOM with this example WAD and walk through this area, observing its main features as they are described forthwith.

[Linguica]

THE ENTRANCE CORRIDOR

The new area has been added at the end of the marble corridor at the top of the one-way staircase. The corridor has been extended to the east, with the two “halves” of the maze area to the north of it.

The main east / west section of the extended corridor has a trigger line just before the entrance to the maze. This acts like trigger line A in the preceding: as the player passes it, it plunges the eastern end of the corridor into darkness. A special line of type 35 (W1 Light Change to 35), tagged to the eastern sector of the corridor, has been used to implement this.

At its eastern end, the corridor turns to the north to meet a short additional sector. The line bordering these two sectors has the trigger action 80 (WR Light Change to Brightest Adjacent) on it to turn the corridor lights back on. This action takes the new light-level setting from the adjacent sector with the highest brightness setting. As the sectors at either end of this corridor have the same brightness level as the corridor originally had, the lights will always come back up to the starting level.

[Linguica]

EXTRA WARNINGS

The walls of the corridor have MARBLE1 on them to match the corridor leading in from the staircase. Close to the lighting trigger lines, though, the corridor walls have been embellished a little, to signal the presence of these triggers to the player. Not that there is really very much that the player can do to avoid them — the warning is really to panic the player a little. Having discovered what the warnings mean by crossing the first trigger, a player may hesitate before crossing others. Similar warnings have been placed at each entrance to the main maze, too.

The warning itself is provided by small alcoves placed next to each end of the lighting trigger lines. These alcoves have conspicuous textures on the back walls. Next to triggers that turns lights off, BFALL1 is used, while by the line that restores the main corridor lights, SFALL1 is in use. (I haven’t bothered putting any notification against the lines that restore the inner maze lights — I thought players should discover these lines for themselves!)

All of the lines with these warning textures have the special attribute 48 (Scroll Texture Left) assigned to them to make them really noticeable. The construction of the alcoves is completed by using BROWNHUG on their side walls.

Note that these small alcoves have not been made into sectors of their own, because they have no settings different from those used in the adjacent part of the corridor.

[Linguica]

IN THE MAZE

The left and right parts of the maze have been drawn using the texture CRATE2. This is generally a good texture to use in maze areas, although it doesn’t really matter what is used here at the moment, because the full development of the maze itself will, no doubt, result in much further modification of the textures used.

The triplines required to turn the main maze lights off and back on again are provided by two lines across the entrances to each part. The inner lines of each half of the maze (lines C and E) use special line-type 79 (WR Light Change to 35) to turn the lights off as each maze sector is entered. The outer lines, (D and F) use special line-type 80 (WR Lights Change to Brightest Adjacent) to turn the lights back up again as the player leaves the maze this way.

In my implementation, I have made each of the areas between these pairs of triplines into sectors of their own, and set their lighting levels to 144 in order to have them act as buffer zones between the outer corridor and the inner maze areas. This allows the retrigger that restores the lights to operate regardless of whether the outer corridor is in darkness or not, by providing an illuminated adjacent sector for each half of the maze.

You could add a little extra sting in the tail of this lighting arrangement by dispensing with the buffer sectors, so that the inner maze areas border directly on the corridor (or by tagging the triggers to the buffers as well as to their own half of the maze). Doing this would make the inner areas rather more complicated to explore until the player discovers how to turn the outer corridor’s lights back on. (I’ll leave you to work out why!)

[Linguica]

FURTHER EMBELLISHMENTS

Just to be really mean, I added an extra internal line to the inner area of the left part of the maze (line H in the earlier figure). This has a special attribute of 104 (W1 Light Change to Darkest Adjacent) and is tagged to its own half of the maze. In my maze, even if players work out how to get this far with the lights on, they will still have to find their way out in the dark.

You might like to wander around a bit through the various parts of the maze to satisfy yourself that it does indeed operate as described.

[Linguica]

COSMETIC CHANGES

I made a few cosmetic variations by altering some floor and ceiling heights, and a couple of textures. MARBLE1 is used on all upper essentials, with the upper unpegged flags set in all cases, while NUKE24 appears on all lower essentials. This latter texture is usually used on 24-pixel edges around nukage- slime pools, but it blends well here, too. The side walls of the entrance buffers use MARBLE1, with Y-offsets of 16 units to ensure correct alignment with the walls of the corridor. Finally, I placed a few floor lamps around the place for effect — and to provide something for the player to navigate by in the dark!

[Linguica]

YOUR TURN

Once you have taken a look at this example WAD for yourself, you should examine the map in the editor, noting the main features of its construction. You may then like to experiment by building a similar area in your own WAD, with or without embellishments of your choice. Leave the maze areas fairly open for now — they will be developed later — and don’t extend them out much further than the area they occupy in the example.

[Linguica]

A FINAL STAB IN THE BACK

Lastly, as a sort of coda to this room on remote-control sectors, you may care to add a further little development at the top of the one-way stairs, just to add to the players’ misery in this area. I’m thinking of another room full of monsters to surprise them from behind.

[Linguica]

ADDING ANOTHER ROOM WITH A DOOR

Start by adding two sectors as shown. These represent a door sector (to be hidden, of course) behind the MARBFACE texture at the western end of the marble corridor; and a room beyond it. Use STONE2 as the texture for the new lines.

I'll leave the appearance of the new room up to you at this point.

The outer face of the door needs MARBFACE on its upper level, to preserve the original appearance of the corridor at this point, and this line should be flagged as Secret on map. The inner face of the door should use STONE2, along with the through-door walls (the latter with their lower unpegged flags set). As usual, make sure that the right sides of the appropriate lines of the door sector face the correct way.

[Linguica]

TRIGGERING THE DOOR

The new door is to be triggered in several ways: first, there should be a single trigger line of type 4 (W1: Door Open Wait Close) some way along the marble corridor to the east. Apply this special attribute to an appropriate line in your WAD and then tag it to the door sector. This line will act in a similar fashion to the trigger line on the darkened stairway out of the platform room, enabling monsters to ambush the player from behind. The door will open long enough for the monsters in it to see the player and awaken.

When this happens, the monsters in the room will move towards the player and should manage to leave the room before the door closes. By placing a standard line-type 1 trigger on the back face of this door, though, any who haven’t emerged by the time the door closes but who are on the track of the player, will be able to open the door when they reach it. Therefore, set the rear face of the door to line-type 1.

Why not just set the corridor trigger to a type that leaves the door open? Well, hopefully, the player will be too busy dealing with the monsters emerging from the room to bother too much about the door itself, initially. By the time the bad guys have been dealt with, and the player wants to enter the room behind it in search of loot, the door will be firmly closed. The trigger line that opened it at first will not now reopen it — it’s a single trigger action, remember — so the player must find another way to open this door.

Putting an impact trigger of type 46 on the face of this door will provide this. Do that now, tagging the outer face of the door to the door sector. Players can now re-open this door by firing at it. It may be a while before they think to try it, though. On the other hand, they may not need to think of it — stray shots from the fight that has just taken place will, in all likelihood, have caused the door to open anyway!

Another retrigger line, this time of special type 75 (WR Door Close Stay) tagged to the door sector, and located somewhere in the corridor, will take care of this. With this modification, players who withdraw to fight from the eastern end of the marble corridor will close the door themselves when they do approach it. Again, it may be a while before they think to shoot at it to reopen it, as they will probably not realize that it was their shots that opened it before.

Finally, I added a further little surprise in the form of another line of type 75 to close the door as the inner room is entered. This may panic players a little—by now they probably won’t immediately think of trying to open the door in the normal way. Of course, there will need to be some goodies placed here to lure players far enough into the room to trip this line, but I’ll leave that for another Sortie.

The final arrangement of trigger lines for this new door is shown below.



When you’re happy with the arrangement of triggers in this area, add a few monsters to the room (just at difficulty levels 4 and 5, for now) and then save this WAD as D2WAD17A.WAD and see how well it all works.

[Linguica]

EXIT: MOPPING UP AND MOVING ON

This room introduced you to the idea of tags between lines and sectors, to provide sectors that can be activated from afar. You have now seen more of DOOM’s doors and seen some fancy tricks with the lights.

The next room will continue this theme of activating sectors remotely and show you how surfaces other than the floors of sectors can be moved.