Demon Gate Mega Collection/DemonGateMegaCollection.bin/text/neat.txt

Text File | 1995-09-06 | 14KB | 333 lines

                                Neat WAD design

There are of course a lot of neat things you can put in your WAD. Currently
I've only put in the following small thing:

  1.  Door on top of Lift
     or "Hallways that pass without holes in the floor".
  2.  Descending Stairs
  3.  Switches and textures


                            1. Door on top of lift
                ======================

The title says it all. If you have two hallways that cross in a square sector,
you can basically make this sector into a combination of a lift and a door.
Meaning that the lower part of the sector is a lift, while the upper part is a
door. I'll try to draw it in a 3d way:

        ----------------x-----------x----------------------
               /|             |\
              / |        | \
             /  |        |  \
    ----------------x-------------------x-----------------------
            |   |        |   |
            |   | /          \    |   | <------DOOR
            |   |/           \|   |
        ------------|---x-----------x---|------------------
            |  /|        |\  |
            | / |        | \ |
            |/  |        |  \|
    ----------------x-------------------x-----------------------
               /|   |           |   |\
              / |   | /          \ |   | \
             /  |   |/           \|   |  \
            /   |   x-----------x   |   \
           /    |  /             \  |    \
          /    | /          \ |      \
             |/           \|
            x-------------------x
               /             \
              /        ^          \
             /        |           \
                /        |        \
           /          LIFT         \
          /                  \


I figured this out on my own, and published it to the doom editing mail list in
October 1994. However at the time this was a well known effect, and even id
used it in DOOM ][. However I'll include my example wad from back then:
doors.zip (9K)


                            2. The Descending Stair
                =======================

How to make a raising stair is well known from the original DOOM levels, but
it's actually also possible to create a descending stair. It's not too
complicated, as the descending stair looks much like the raising one, at least
on the map:

    (The numbers are sector numbers)

    :        :
    :    7    :
    |        | (The dotted lines are two sided
    x...............x  linedefs, while the dashed lines
    |        |  are one-sided)
    |    6    |
    |        |
    x...............x
    |        |
    |    5    |
    |        |
    x...............x
    |        |
    |    4    |
    |        |
    x...............x
    |        |
    |    3    |
    |        |
    x...............x
    |        |
    |    2    |
    |        |
    x...............x
    |        |
    :    1    :
    :        :

When you have made this map, you should assign a floor height of 48 to the
sectors 2, 3, 4, 5, 6 and 7 while sector 1 should have a floor height of 0. Now
you can set up the normal raise stair linedef and tag it to sector 1. When the
linedef is activated, the stair will snap into place immediately. Be careful
when you design the stair, as each step will have a height of at most 8 pixels,
which can easily prove to be too little.

The descending stair was first demonstrated by Sean Malloy
([e-mail]) who released the dnstair.zip (3K). The effect is also
demonstrated in special1b.zip (73K), where you can find it by going through the
SKY door, turn right and press the switch. This should lower the floor you're
standing on into a descending stair.

To get around the 8 pixels limit on the height of each step, you can create
"dummy" sectors where the floor height of the dummy sector sets the level you
want the step to drop to. To illustrate, consider the following map:

            (The numbers are sector numbers)

    :        :
    :    7    :
    |        |
    x...............x--x
    |        :  |
    |    6    :12|
    |        :  |
    x...............x..x
    |        :  |
    |    5    :11|
    |        :  |
    x...............x..x
    |        :  |
    |    4    :10|
    |        :  |
    x...............x..x
    |        :  |
    |    3    :9 |
    |        :  |
    x...............x..x
    |        :  |
    |    2    :8 |
    |        :  |
    x...............x--x
    |        |
    :    1    :
    :        :


Here you can set the height of sector 1 to be 0, and set a height of 120 for
the sectors 2, 3, 4, 5, 6 and 7. The sectors 8-12 should be a stair from height
0 to 120 with a step height of 20. You can set the ceiling height of each of
these sectors to equal the floor height, which should conceal the sectors
completely (if you align the textures). Now set up a linedef like 23 to all the
sectors 2, 3, 4, 5 and 6. The linedef 23 drops the sectors to the lowest floor
height in the adjacent sectors, which means that each step is lowered to the
floor height of the adjacent "dummy" sector.

This special effect is also demonstrated in spcial1b.zip (73K). You can find it
by taking the door to the south east. Go straight through the following room,
and press the switch in the hallway. The hallway behind you should then drop
into a combined stair that goes down and back up. This effect was described by
Ray Greenwell ([e-mail]).

The previous way of creating the descending stair works well if the stair goes
down alongside a wall. If that's not the case, you'll have to experiment with
other linedefs and other ways of concealing the dummy sectors. (Like making
them small, or creating them away from the map in a place where the player
never enters. See how it's done in the invisible raising stairs section).


                3. Switches and textures
                ========================

The special effects in this section are all inspired by Drake O'Brien. To view
the effects in question, go through the door marked "Switches" in spcial1b.zip
(73K). Here you will see a normal switch straight ahead. Try to activate it
using the spacebar. It doesn't work? OK then try to shoot it. A hole should
appear in the switch revealing another switch below. You can activate the
switch below using the spacebar.

Now you can turn left, where you will see a new type of switch with four
actions. The first four times you activate this switch, a new door will open.

Now go through the fourth door you have opened, and operate the switch straight
ahead. That should start the "road runner" animation. (At the same time the
door back to the main area is opened again).

                The Exploding Switch

This is an easy application of new textures to switches. The switch isn't
actually exploding, but a hole appears in it when it's shot. The same technique
can be used to create glass that breaks when shot. To implement this I
recommend you get a copy of WinTex or DeuTex.

You can't make your own new switch texture, but you can override one of the old
ones. This means that you should be very careful when you're selecting the
textures you wish to redefine. Only redefine textures textures where you're
sure you don't need the original.

To make the special effect you need to Apply a switch on a 2 sided linedef.
This is impossible with the original DOOM switch textures, as they are all
multipatch textures. So you need to redefine one of the SW1nnn, SW2nnn pairs,
where the "nnn" is any switch name. Both the SW1nnn and SW2nnn textures should
be redefined to be one-patch textures, or a texture suited for a 2s wall. In my
WAD I've created a texture that consists of the switch and nothing else (one
patch). The second texture (SW2nnn) should be almost the same as the first
texture except now you have added cyan where you want a hole in the switch. You
might also change the look of the switch around the hole so that it looks bent.

In the WAD, the effect looks like this:

            (The numbers are sector numbers)

        x---x
        | 2 |
    x-------x...x---x
    |        |
    |      1    |
    |        |
    :        :


Where sector 1 is the room you walk around in, and sector 2 is a small sector
used to create the switch. The switch texture should be applied to the 2-sided
wall between sector 1 and 2. At the same time a G1 action should be associated
with the linedef. This way the texture will change when the switch is shot. On
the back of sector 2 you can put any kind of texture you wish the player to see
through the hole in the switch. In my WAD I've put another switch here.

So why does it work? Why can't the switch at the back of sector 2 be activated
before the new exploding switch has been shot?

The answer is quite simple:
When the player presses the spacebar, DOOM will look at the linedefs inside the
reach of the player with the closest lindef first. Only linedefs with an
associated action is considered, and linedefs that can only be activated once
(S1, G1 or W1) will only be considered if they haven't already been activated.
At the end DOOM will have the closest non-activated linedef with an associated
action. If this linedef can't be activated by the spacebar, nothing happens. If
it can be activated by the spacebar, the action is performed.

The rules for linedef activation (As I know them - There are errors in this):

 Line
 type:                              Activated by:

   G  The player shoots through or at the line. Any shot can trigger multiple
      "gun" actions.

   W  The player moves so that his centre crosses the line. If the linedefs
      are overlaid, the player can activate as many as 9 "walk" linedefs just
      by moving one pixel.

   S  The player presses spacebar standing in front of the line (facing the
      line). There must not be any non-activated lines (of ANY type) between
      the player and the line in question. The player can only activate one
      "switch" linedef at a time.

Which in this case means that before the front switch is shot, it will be
impossible to activate the switch at the back of sector 2.

                Multiple action switch

You've already seen the multiple action switch. The exploding switch from
before is actually a multiple action switch. Instead of applying a G1 action to
the front linedef, all you need is to apply a S1 action, and the player can
activate the switch twice by pressing space. Instead of making a hole in the
switch in the SW2nnn texture, you can make it disappear completely, by using an
all cyan patch. That way the switch underneath will be completely exposed when
the first switch has been activated. This can be repeated many time with
different looking switches. In my WAD I've created a four action switch. To
give the impression that the switch isn't disappearing, I've made the gap
between one switch and the next as small as one pixel. This way it looks as if
it's not four different switches you activate, but one switch that changes four
times.

The switch textures I use only change a little from action to action, but
remember that they need to be applied to 2 sided walls, so you can't use
overlaid patches.

                Broken Glass

It should now be easy to see how you can apply the same technique from the
exploding switch to make a glass texture that breaks when shot. Simply apply a
glass texture to one of the SW1nnn textures, and a broken glass texture to the
corresponding SW2nnn texture, and apply a G1 action to the glass linedef in the
WAD. That way the glass will appear to break, when shot. This effect was
invented by Alberto Barsella ([e-mail]).

                Animated Switch

The last effect in the "switches" room, is an animation triggered by a switch.
This effect was first implemented by Brian K. Martin ([e-mail]).
The effect requires a bit more of the WAD designer (Yes that's you). First of
all you need to know which textures form animation starts and ends. Using
WinTex this is no big problem, as all the animation start and end textures can
be selected from a drop down menu, so I won't explain that in any further
details (If you're not using WinTex that's your problem, not mine).

To set up the effect, you need to define the SW2nnn texture as a part of the
animation between the "anim start" texture and the "anim end" texture. For
instance your texture definitions could be like this:

      SW1nnn       # The first frame of a switch
      ANIM_START   # The start of an animation (Select one of the start
                      points from the WinTex menu)
      SW2nnn       # This is the second frame of the switch from before.
                     Since it's between ANIM_START and ANIM_END,
                     it will become part of this animation.
      SOME_TEX     # Then follows a few frames of the animation
      SOME_MORE
      ...
      ANIM_END     # This is the last frame corresponding to the animation
                     started before. You can select this from the same
                     WinTex menu.

Remember not to use the actual names listed above. Instead you should find
original animation and switch textures from DOOM and redefine them.

You may want to be able to start an animation elsewhere, meaning that you don't
want the animation to be displayed at the switch being activated, but want it
somewhere else. To achieve this you need to overlay two linedefs. To overlay
linedefs, you have to merge the end vertices, but keep two (or more) separate
lines between the same two vertices.

Only one of the overlaid lines will be shown when the WAD is playing, so the
other will be completely invisible. This other line could be set to hold the
animation, while the line that shows should contain a switch texture. Remember
though that the line that shows will not be activated when the animation is
turned on. You might think that it's stupid to create an animation that doesn't
show, but now you can set up a line elsewhere, and give it the same sidedef as
the hidden overlaid line. That way the animation is displayed here.

This last effect requiring overlaid linedefs has not been implemented in my
example wad.

-------------------------------------------------------------------------------
DOOM is a trademark of id Software.
-------------------------------------------------------------------------------
Jens Hykkelbjerg / [e-mail]