RMB: Reject Map Builder Version 2.1

Software by Jens Hykkelbjerg


written by
Jens Hykkelbjerg and Steve Benner

    1. What is RMB?
    2. What is the REJECT resource?
    3. What is REJECT efficiency?
    4. Why use RMB? Can't any WAD editor do this?
    5. I'm not a WAD designer but can I use RMB on other people's WADs?
    6. Will RMB alter the way the game plays (apart from speed)?
    7. Tell me more about these special effects
    8. Hmmm... Interesting. What use is it, though?
    9. So I can use RMB with impunity, then?
    10. How do I optimise someone else's WAD safely, then?
    11. How thorough is RMB?
    12. Does RMB work with any WAD?
    13. OK, so how do I use RMB?
    1. Installation
    2. RMB Utilities
      1. DxBETTER
      2. INSPECT
      3. RMB
      4. EFFECT
      1. Combining REJECT optimisation and special effects
      2. The structure of an Options file
      3. RMB options: a full list
      4. Processing time implications of RMB options
    4. Miscellaneous
    1. Explanation of argument types
    2. Individual Option Details
    3. Combining Options


1.1 What is RMB?

Reject Map Builder (RMB) is a DOS-based program designed to allow DOOM users and level-designers to both optimise and customise the REJECT resource associated with either their id-supplied DOOM.WAD or other third-party PWAD files. This includes any DOOM 1, DOOM ][ or Heretic PWAD.

Using RMB can provide greatly improved playing-speed, particularly in complex WADs with many monsters. The REJECT resource also provides scope for the WAD designer to implement a number of special effects, to which RMB provides full and easy access. The RMB package contains utilities to inspect and report on REJECTs in any single- or multi-level WAD. There are also a few sample WADs for DOOM 1 to demonstrate the potential of the special effects which become available through the REJECT map.

1.2 What is the REJECT resource?

The purpose of the REJECT map within a WAD file is to tell the Doom gaming engine whether or not it is feasible for a monster located in a particular sector to see anything to shoot at, or attack, thereby saving the engine from having to work this out for itself while a game is in progress. Within the resource, the information is stored as a series of bits, which, on a sector by sector basis, we may think of as a table, thus:

                    Sector the player is in
                     0    1    2    3    4 ....       NB: Doom never
                  +----------------------------           uses this table to
  Sector the   0  |  b    b    b    b    b ....           determine what the
   monster     1  |  b    b    b    b    b ....           PLAYER might be able
    is in      2  |  b    b    b    b    b ....           to see.
               3  |  b    b    b    b    b ....
               :  |  :    :    :    :    :
               :  |  :    :    :    :    :

The value of each bit, b, has the meaning: (0) player's sector can be seen (at least in part) from monster's sector; (1) player's sector cannot be seen at all from monster's sector.

The following WAD map, for example:

    |             :                :           |      The numbers indicate
    |      1      :       2        :     3     |      SECTORS
    |             :                :           |
    |             o----------------o-----------o      Dashed/solid lines are
    |             |                                   1-sided LINEDEFs
    |             |
    |             |                                   Dotted lines are
    o.............o                                   2-sided LINEDEFs
    |             |
    |      0      |                                   o's are VERTEXES
    |             |

would give rise to the following REJECT table:

                      (Player sector)
                     0    1    2    3
               0  |  0    0    0    1
   (Monster    1  |  0    0    0    0
    Sector)    2  |  0    0    0    0
               3  |  1    0    0    0

which indicates that all sectors can see every other sector, with the exception of sectors 0 and 3, which are not in direct line of sight of each other.

Note that this does not mean that any monsters in sector 0, say, will definitely see the player who enters sector 2: it merely means that it is feasible for them to do so. Any number of factors may prevent a monster from actually spotting the player during play - not all of the player's sector may be visible from the monster's actual location; the monster may be looking in the wrong direction and so on. In the example above, the game engine will have to resolve the actual line of sight between a monster in sector 0 and a player in sector 2 at game time. On the other hand, the presence of a 1 in the REJECT map indicates immediately to the game engine that it is not feasible for monsters to see from one of these sectors to the other. In such cases, the engine will not bother to perform any line-of-sight (los-) calculation and will move on to considering other monster-occupied sectors. As los-calculations are often not trivial, any such calculations that can be avoided while the game is in play will improve game speed and make frame updates smoother. Obviously in the simple example above, the amount of work being saved is small: the benefits during play provided by this particular REJECT map are probably undetectable. For large WADs with many monsters and complex geography, however, the time savings that can be had from a fully optimised REJECT table may be considerable and can make all the difference to the playability of the level.

1.3 What is REJECT efficiency?

It should be obvious from the discussion above that, in general, the more 1's there are in the REJECT map, the greater the potential savings in los-calculation time. RMB uses this simple fact to provide a rough indication of the effectiveness of a WAD's REJECT map. Whenever RMB is used to create or inspect a REJECT map, it will count the number of 1's in the resource and then report this as a percentage of the total number of entries. This so-called efficiency figure will only give a rough indication of the amount of speed-up of the level attributable to the REJECT map (this will obviously depend ultimately on the number and distribution of monsters in the level) but for most practical WADs a high efficiency rating usually means that the speed-up will be good in most areas.

1.4 Why use RMB? Can't any WAD editor do this?

Although it is a simple structure to understand, the calculations which are needed to generate the REJECT map successfully are quite involved and can be fairly time consuming, even with a fast processor. Consequently, the majority of WAD editors currently available prefer not to bother about this resource, concentrating instead on other areas of WAD construction. Most editors simply generate an empty REJECT, (i.e. a table entirely of 0's) which benefits playability not one iota. It was to address this lack that RMB was written: with RMB, the Doom level developer can easily integrate automatic REJECT generation into his edit/play development cycle. Or he may choose to leave REJECT optimisation to the end, using RMB just on the final WAD.

1.5 I'm not a WAD designer but can I use RMB on other people's WADs?

You may be tempted to use RMB to try to speed up your favourite third-party WAD. This is OK provided you proceed with caution, as explained below.

1.6 Will RMB alter the way the game plays (apart from speed)?

The answer to this question is no.. and yes! To understand this answer, let us look briefly at how the Doom engine resolves monster behaviour during play. In grossly over-simplified form, the Doom monster control loop works something like this:

for each monster
  if the REJECT map says it's feasible then         <-- i.e. REJECT entry of 0
    if player is in sight then                      <-- note los calculation
      if monster is awake then                     \
        if monster within range of player then      |
          attack player                             |
        else                                        |
          move to get in range                      |
        endif                                       |    This part
      else                                           >   skipped if player
        wake monster                                |    cannot be seen
      endif                                         |
    else                                            |
      if monster is awake then                      |
        try to home in on player                    |
      endif                                        /
    if monster is awake then                       <--  Note the duplication
      try to home in on player                     <--   of this
next monster

This shows how a REJECT entry of 0 makes no difference to Doom's monster decision-making: hopefully you can also see that in the cases where the REJECT map contains 1's (where a los-calculation would definitely fail because the two sectors are not in sight of each other) there is no difference in the logic either: a los-calculation is merely avoided. Rest assured, therefore, that supplying Doom with a REJECT map that has all unsighted sector pairs marked will make no difference to monster behaviour during game play. The only change you should see is an increase in playing-speed.

What about the other half of the answer to our question above? How may it come about that RMB can change the playing characteristics of a WAD? Well, RMB is a fully featured REJECT map builder: in addition to its default 'automatic' mode, RMB provides the WAD designer with full access to the REJECT map, allowing individual bits to be set or cleared at will. This can introduce some useful (or at least novel!) special effects which the WAD designer may wish to exploit.

1.7 Tell me more about these special effects

By way of an example, consider our earlier 4-sector map. Here is the REJECT map that RMB would generate by default:

                     0    1    2    3   (Player Sector)
   (Monster    0  |  0    0    0    1
    sector)    1  |  0    0    0    0
               2  |  0    0    0    0
               3  |  1    0    0    0

If this table were to be altered thus:

                     0    1    2    3   (Player Sector)
   (Monster    0  |  0    0    0    1
    sector)    1  |  0    1    0    0         <- one bit changed at 1,1
               2  |  0    0    0    0
               3  |  1    0    0    0

the effect would be to make monsters in sector 1 unable to see any player in that sector! Under these circumstances, the effect during play would be that while in sector one, the player would be immune from attack by monsters in the sector with him. Note, though, that he may still be attacked by monsters from other sectors. Furthermore, if he moved out of sector 1, any monsters left there would then be able to see him and attack him. It is important to remember that this 'blindness' of monsters is a function of the sectors they occupy, not of the monsters themselves. In this example, assuming monsters are not constrained from moving between sectors by other factors, if the player entered sector 1 (from sector 0, say) and was spotted by a monster in sector 3, that monster would wake up and would start to pursue (and possibly fire at) the player. The monster would move from sector 3 into 2, where it could still see the player and so may continue to fire. Once it entered sector 1, however, the player would 'disappear' from view, as far as the gaming engine is concerned, and the monster would now cease its attacks. Note from the logic presented earlier, though, that the monster would continue to track the player and, of course, would resume its attack as soon as either it or the player left sector 1. A single bit change in the REJECT map has produced an unusual but interesting behavioural change in the game.

1.8 Hmmm... Interesting. What use is it, though?

We could make a couple of other changes to the map:

                     0    1    2    3           Note the whole of the
                  +-------------------          player sector 1 column
   (Monster    0  |  0    1    0    1           set to 1's.
    sector)    1  |  0    1    0    0
               2  |  0    1    0    0
               3  |  1    1    0    0

Here we have produced a map where the player is completely 'safe' in sector 1: no monster anywhere can see him there. There is potential here for producing 'safe havens' in areas of complete mayhem, areas where a player can catch his breath before returning to the fray (provided he can recognise the 'haven' and get to it, or course :-) - better than having the player keep reaching for the pause key!

Alternatively, here:

                     0    1    2    3   (Player sector)
    (Monster   0  |  0    0    0    1
     sector)   1  |  1    1    1    1          <-- whole row set to 1's.
               2  |  0    0    0    0
               3  |  1    0    0    0

we've produced a sector (1, again) which is completely 'blind'. Monsters in it will not see anything in any sector. Note that although these monsters will not awaken or attack if the player moves in front of them (they can never see him while they remain in sector 1), they can still be awakened by noises (assuming they're not flagged as deaf, of course - and just what use deaf and blind monsters would be, I'm not sure: although even those monsters will wake up if hit with shot) whereupon they will start tracking the player - and will fall upon him once they are no longer in sector 1! There is scope here for rooms full of sleeping monsters through which a player must creep in order to find the means of disposing of them.

These are just two examples of special effects which can be introduced to a WAD by means of the REJECT map. Naturally, RMB provides simple access to these and to a range of others for WAD designers - full details of each effect option are given in the "Options Reference" section of this manual. You can introduce as many (or as few) such effects as you wish - none of them add anything to the size of a WAD and they may even speed it up into the bargain (they will certainly never slow it down any): of how many things can that be said in Doom? By default, of course, RMB applies no special effects at all, so that you need not worry about any such things being introduced unexpectedly to your WADs.

1.9 So I can use RMB with impunity, then?

Up to a point, yes. If you are the designer of a WAD, you will of course know whether your WAD needs any of the special effect settings that RMB provides and you will be using RMB accordingly. If you don't want any special effects, then just use RMB to optimise the REJECT table for speed and away you go. If, however, you are using RMB to try to improve the performance of someone else's WAD, you should proceed with caution. The reason for this is that the original WAD author may have edited the REJECT map to produce some special effect or other at some place in the WAD. Running RMB on such a WAD will destroy the tailored REJECT and replace it with a 'plain' (albeit optimised) one and the special effects will be lost. This could completely destroy the functionality of the WAD. Naturally, applying RMB to a WAD which already has a fully optimised REJECT map will achieve nothing (but then it shouldn't do any damage, either).

1.10 How do I optimise someone else's WAD safely, then?

The recommended method for using RMB with another designer's WAD (where you know nothing about the REJECT map beforehand) is as follows:

Start by making a back-up copy of the WAD: that way it doesn't matter what damage you do! Then use the RMB's INSPECT utility (described later) to test the WAD for special effects. If INSPECT finds special effects it is, of course, not a good idea to process the WAD with RMB, as that would remove the special effects.

INSPECT only reports symmetry errors, so some special effects could still be hiding even if INSPECT reports that there are none. If INSPECT doesn't find any special effects the efficiency is reported. A reported efficiency of 0 indicates that the REJECT map is empty: in all such cases, RMB can be used quite safely, as there is no information in the REJECT map to damage. A very low but non-zero efficiency on the other hand, (say only a dozen 1's out of a few thousand) means that you probably have a WAD where the author has deliberately set bits to achieve special effects but has not bothered to optimise the rest of the table. It is probably best not to apply RMB to such a WAD, unless you can be sure of keeping the existing 1's intact. Such WADs are likely to be very rare in reality - any author so REJECT-aware would almost certainly have optimised the table (unless, of course, they didn't have a program as good as RMB!) In cases where INSPECT reports a high efficiency there is almost certainly nothing to be gained by applying RMB to the WAD. RMB may produce a higher efficiency but the resulting speed difference may not be detectable and, of course, you will have destroyed any special effects in the process!

1.11 How thorough is RMB?

To perform a complete check on all inter-sector lines-of-sight, in any fair-sized WAD, would require a vast number of calculations. In order to achieve a good working compromise between the number of absolute 'blind pairs' which are located and the time taken to find them, RMB uses a number of processing short-cuts of which the WAD designer needs to be aware. There are options to extend RMB's processing to locate more true 'blind pairs' but these are not likely to be needed very often: usually only when trying to build special effects, (when it is probably easier to take full manual control of the problem areas anyway,) or for WADs where you need the absolute maximum amount of speed-up possible.

Another point to bear in mind about RMB's methodology is that it always defaults safe - by this we mean that it will, unless instructed otherwise, introduce no extraneous special effects (after all, nothing spoils a WAD more than monsters who don't want to play!) Once again, special processing 'limitations' are imposed to ensure this behaviour.

The first such limitation is that RMB considers only lines-of-sight in the 2- dimensional plane of the WAD map: no height differences are taken into consideration. This limitation is imposed for reasons of both speed and safety. As you will be aware, height differences between sectors may be only a temporary thing in DOOM: consider the following area of a map, seen here as a side view:

                            4      5
                         |------|------|        The numbers identify
                         |         o   |        sectors;
                         |         -\  |
   Sector 4 is a lift in |          /\ |
   the 'up' position. -> |------|------|
                         |      :   ^
                         |   S  :   |
       1       2      3  |   H  :   example player
    |------|------|------|   A  :   position
    |                        F  :
    |                        T  :
    |                           :

Here, sectors 4 & 5 are not in view from sectors 1, 2 & 3 (and vice versa). RMB will be unaware of this, however, as it will only consider the map view:

    |      :      :      :      :      |   where every sector appears to
    |  1   :   2  :   3  :   4  :  5   |   be able to see all others.
    |      :      :      :      :      |

This is a desirable state of affairs, because we would not wish to block the line of sight between sectors 3 & 4 which will exist as soon as the lift descends. Similar arguments also apply either side of doors.

There being no mechanism for changing resources during play, the REJECT table must allow for all eventual lines-of-sight. The only limitation which results from RMB's methodology in the above example, is that the true obstruction to the lines-of-sight between sectors pairs 1-5 and 2-5 will go unrepresented in the REJECT map and in these particular instances, Doom will have some unnecessary los-checking to do at game-time. This is a small price to pay for correct monster behaviour in this area. Any time you spent searching out and correcting the few sector pairs that are affected by this short-coming would most likely be time wasted.

The other short-cut that RMB uses in order to speed up its calculations, is to treat all sectors that are wholly enclosed within another sector (and consequently have no 1-sided LINEDEFs) as part of the enclosing sector. In most WADs, this greatly cuts down the number of sectors that RMB needs to consider (inter-sector connections rising as the square of the number of sectors). Think of this as processing by the 'room', rather than by the sector and you'll see that it makes sense. A variety of options exist to make RMB vary this short-cut to suit your individual WAD (these are explained in detail in section 3 of this manual): most of the time you should find that the default mode works just fine.

1.12 Does RMB work with any WAD?

RMB v2.0 will work with any WAD, single- or multi-level, IWAD or PWAD, produced with any WAD editor, provided that a REJECT resource of the correct size is present in the WAD. (Its contents are of course immaterial.) RMB will work with WADs for Doom (v1.1 - 1.666), Doom2 or Heretic. If you encounter a problem WAD, please contact the author (contact details are at the end of this manual) with a description of the problem.

1.13 OK, so how do I use RMB?

Read on: the next section of this manual tells you how to install the program and describes the various utilities supplied with it. After that, Section 3 gives full details of the various options which can be used with RMB.


2.1 Installation

Installation of RMB is very simple: just unpack it into its own directory (you've probably done this already). You will find that apart from the main RMB.EXE itself, there are a number of other .EXE utilities (these are described below) as well as some .BGI files which are required for correct graphical display of the map as RMB processes the WAD. There is also a couple of batch files which you can use to run through all of your (registered copy) Doom levels, to optimise them one by one: details below.

2.2 RMB Utilities

NOTE: When the syntax of a command is given, the follow conventions apply:

For example, for a command specified thus:

    EFFECT <WADfile> [<level id>] {BLIND, SAFE} {0, 1} {<sector number>, ALL}

any of the following are valid:

    effect myfile.wad blind 0 22
    effect my2file.wad E1M2 safe 1 43 (for use with Doom 1 WAD) effect
    myfile.wad MAP02 blind 0 all (for use with Doom 2 WAD)

(An explanation of this command is given in section 2.2.4, below.)

Note also that all examples assume that the commands are typed while in the RMB directory. WAD designers who are likely to make heavy use of RMB may wish to prepare DOS batch files to perform the necessary directory switching for them: I (Steve) use a set like this:

FIX.BAT invokes my editor with a chosen WAD

cd waded (no, I don't use DEU - just call me perverse)
waded %1.wad
cd ..

MAKEFX.BAT lets me edit my RMB option file (see below)

edit waded\%1.rej


rmb ..\waded\%1 ..\wads\%1 %2

TRY.BAT lets me play-test the WAD

doom -file wads\%1.wad -devparm -warp %2 %3

TRYRAW.BAT lets me play-test the version without REJECT

doom -file waded\%1.wad -devparm -warp %2 %3

No doubt, each developer will prefer their own.

2.2.1 DxBETTER

The D1BETTER.BAT utility supplied with RMB will run through all of your (registered copy) Doom1 levels, optimising them one by one. To use it, copy your DOOM.WAD to your RMB directory, type D1BETTER then go and make some coffee. When you have finished your cup(s) of coffee, rename your original DOOM.WAD to something like DOOM.BAK, copy the new one back to the DOOM directory and try it out. (Remember that when you have changed the original Doom files, Id offers no support...) [If you're short on disk space (and who isn't?) copy RMB.EXE to your Doom directory, make a file called DOOM.REJ with a single line saying NOMAP in it and then type \RMB\D1BETTER (or whatever is necessary to locate the batch file). Of course, if this goes wrong, you'll have to re-install DOOM.WAD. But then you've got the original disks, haven't you?] Another batch file called D2BETTER.BAT is supplied to work the same wonders with the Doom2 WAD. It is used in precisely the same way as D1BETTER, except that you will have time to make and drink a large flask of coffee, go for a jog, wash and polish the Porsche (don't worry if you don't have a Porsche right now: you may have one by the time D2BETTER finishes...;-)


The INSPECT utility will report on a WAD's current REJECT map without changing it. This is useful for finding out whether a third party WAD has anything in its REJECT or not, prior to using RMB on it. It also can be used to provide reassurance that any specific processing you requested has taken effect. The statement syntax is:

INSPECT <WADfile> [<level id>] [{<sector number>, TEST}]

<WADfile> specifies the path and filename of the file to be inspected. Be sure to include the .WAD file extension.

Use the optional <level id> parameter to specify the level you want to inspect in a multi-level WAD. Levels are specified in the standard ExMy format for Doom1 WADs, or in MAPnn form for Doom2 WADs. Omitting this parameter results in just the first map in the WAD being inspected.

When a <sector number> is specified, INSPECT will report the list of all sectors that are currently flagged as potentially visible from the sector of interest.

>inspect c:\wadfiles\think12.wad 2

Sectors visible from sector 2: 0,1,2,...

If no <sector number> is given, INSPECT will just calculate and report the efficiency of the WAD's current REJECT map.

e.g. >inspect c:\wadfiles\think12.wad

Efficiency: 40%

Instead of the sector number you can also specify TEST. In that case INSPECT will test whether the REJECT map is symmetric. The REJECT map is symmetric if for all sectors A that can see sector B, B can also see A. Most special effects will destroy this symmetry, so the TEST option can be thought of as a test for special effects. In fact, INSPECT will report either No special effects found or Special effects found as a result of a TEST query.

>Inspect c:\wadfiles\think12.wad test

No special effects found...

2.2.3 RMB

Note: The syntax has changed since v2.1

The syntax for the main REJECT Map Builder (RMB) is:

RMB <InputWADfile> <OutputWADfile> [OPTIONS]

Where OPTIONS is a list of some of the following possible options:

  -EnMx           Process level EnMx
  -MAPnn          Process level MAPnn
  -PREPROCESS n   Preprocessing efficiency, n is one of [1..9+] (default: 4)
  -PERFECT        Generates a perfect reject map. (Very slow)
  -DISTANCE d     The maximum distance in map units of a line of sight.
  -LENGTH n       The maximum length (by sector), n is one of [0..150+]
  -DOOR n         The maximum # of doors a LOS can pass. d is one of [1..10+]
  -NOMAP          Don't display the graphics while running.

An interval like [3..7+] means that the value in question should be larger than 3, and it can be larger than 7, but values above 7 are normally not useful.

Example command line:
C:> RMB mywad.wad newwad.wad -e1m1 -prepro 3 -nomap

If the wad only contains one level, you don't have to specify any options. Just the input and output filenames are needed.

The input WAD filename may be the same as the output WAD filename if you wish the original will be overwritten. Most WAD developers will no doubt cringe at this idea and it is certainly not recommended unless you have a back-up of the file. (Some people like to live dangerously, though, and who are we to stop them? See the REJECT.BAT batch file above for one suggested better way of doing things though.)

The options -EnMx and -MAPnn are the level identifiers. Using these options you can specify which level in the wad you want rmb to take care of (only one level can be processed each time rmb is run). If the level is not specified, rmb will process the first level in the wad.

Doom1 example: >rmb c:\wadfiles\starwar2.wad mystar2.wad -e1m2 (Processes e1m2 from starwar2.wad; saves the result in mystar2.wad).

Doom2 example: >rmb doom2.wad doom2.wad -MAP13 (Processes map 13 of doom2.wad).

All the other command line options are equivalent to options that can be used in the .REJ option file. See section 2.3.3 for more information about these options.

During the processing of a WAD, a map of the level being processed is shown on the screen, with the number of the sector currently being processed given in the top left corner of the screen, together with the total number of sectors to process in the level. The map may look a little different from the view of the WAD that you are used to seeing: all 2-sided LINEDEFs appear initially in blue with a selection of 1-sided LINEDEFs in white. As the program looks at each sector in turn and works round all the sector's 2-sided LINEDEFs, lines on the map will turn red (to show that they're being processed) and then cyan (when finished). From the current (red) LINEDEF, it will be possible to see other 2-sided LINEDEFs. The first of these out from the sector being processed will show yellow on the display for a while, finally turning magenta as processing on it completes. As the program progresses, there should always be a red and a yellow line, showing where the program is currently processing los-calculations. The sector count will rise steadily: processing finishes when all sectors have been examined.

When processing is complete, the program will create the specified WAD file, writing the new REJECT map to it, along with the rest of the WAD's resources. The final efficiency of the REJECT will be reported, and RMB will beep to let you know that it has finished (and drag you away from your coffee drinking).

2.2.4 EFFECT

The EFFECT command allows simple special effects to be applied to WAD files through the REJECT map.

The syntax of the EFFECT command is:

EFFECT <WADfile> [<Level id>] {SAFE, BLIND} {0,1} {<sector number>, ALL}

Once again, don't forget the .WAD file extension to the <WADfile> parameter.

The optional <Level id> is either a Doom1 episode and mission number like E2M3, or a Doom2 map number like MAP03. EFFECT will process the specified map or, if none is specified, the first level in the WAD.

The SAFE option makes sectors safe, as described in section 1.8 above. As long as a player is in a safe sector, he can't be seen: monsters won't wake up or attack. The other available effect is BLIND: this blinds a sector so that monsters in it will be prevented from seeing the player, wherever he might be.

The parameter immediately following the SAFE or BLIND keyword specifies the degree of safety or blindness that the EFFECT command will produce. Currently only 0 or 1 are supported here. Their meanings are:

 SAFE: (0) : Sector is completely safe: no sector has sight of it.
       (1) : Sector is safe only from other sectors: monsters within it can
             see the player.
 BLIND (0) : Sector is completely blind: no sectors can be seen from it,
             player cannot be seen in it.
       (1) : Sector is blind only to other sectors: monsters within it can see
             the player in it.

In all four cases above, you can use ALL instead of the sector number for the last parameter. With a degree setting of 0, this will make all sectors totally safe (or blind - there is no distinction between the two, the table being filled with 1's either way): all monsters will be total pacifists. A degree setting of 1 creates a level full of near-sighted monsters, who will only notice players in the same sector as themselves.

Making all monsters blind will make for a very dull game but it may be useful for play-testing a WAD, to check, for instance that all monsters are placed correctly (but do remember that noises will wake them up and cause them to move around) or to see what the absolute maximum REJECT speed-up of the WAD would be like.

Although this command is quite powerful, it is really only intended as a quick way of applying the occasional special effect. For more comprehensive application of special effects, as well as specialist processing, it is recommended that the RMB command be used, in conjunction with an options file: see the next section.

Remember also that if you use the RMB command on a WAD after it has been EFFECTed, you will remove all of the added effects! (Most editors will happily do this for you too!)


2.3.1 Combining REJECT optimisation and special effects

So far, we have demonstrated the use of RMB to optimise a WAD's REJECT table and have presented the utility EFFECT, which introduces special effects to a WAD via its REJECT resource. For some users, the simple application of these utilities as described above will be sufficient. For the serious WAD developer, however, the more convenient and powerful approach will be to utilise RMB options files during WAD development. These allow full control of RMB's optimisation methodology, as well as complete 'manual' access to the REJECT resource. RMB does not need to be invoked in any special way to make use of an options file: all you need to do is create a text file containing the options you wish to apply, making sure that it is located in the same directory and has the same name as the WAD file you wish to process but with the extension .REJ. So, to apply a set of RMB options to MYLEVEL.WAD located in your \NEWWADS directory, saving the new, processed WAD in your \REJWADS directory, you would create an options file MYLEVEL.REJ in \NEWWADS and issue the command:

>rmb \newwads\mylevel.wad \rejwads\mylevel.wad

RMB will automatically notice your \NEWWADS\MYLEVEL.REJ file and apply it.

2.3.2 The structure of an Options file

Note: The way RMB reads the option file has changed since v 2.0

RMB options files do not need to have a particular structure beyond being straightforward ASCII text files, with a single RMB option statement on each line (empty lines are permitted). Options can be entered in upper or lowercase. Options can appear in the file in any order: the only exception being that options intended for particular levels in multi-level WADs must be grouped together under a heading for that level. The first part of the file before the first level identifier contains the default options, which RMB will always use.

A sample .REJ options file should make this clearer (full details of the RMB options used in this example are given in the next section of this manual):


    # This is an example of a multilevel options file, for use with

    # The first lines are the defaults.
     # These options will always be used.

    length 17
     Distance 800

    # Now comes the options used to process E1M1:

     # ^ This marks the end of the defaults, and the beginning # of the options
    that apply to e1m1. # Use MAPxx for options to levels in Doom2 WADs

    Left 311
     Right 217

     # ^ Here end the options for episode 1 mission 1: # options for episode 1
    mission 2 begin.

    Length 14
     # ^ This option overrides the LENGTH option in the defaults section. #
    Read the section Overriding options later. Report 14
     Block 23 56

     # ^ Here the options for E1M1 take over again.

    INCLUDE (4) (6)
    EXCLUDE (2) (3)

    # If RMB is called with a mission that is not in the options # file
    (e.g. "e1m3" here), only the default options at the beginning of # the file
    are used.

    # ==END OF OPTIONS==

To summarise: if you want to apply different options to different levels in a multilevel WAD, you must divide your wad_filename.rej option file into sections started by a line containing nothing but the level id. For WADs containing only one level, you can just use the default options without worry.

2.3.3 RMB options: a full list

As explained earlier, in its default operation, RMB tries to maintain a balance between complete optimisation of the REJECT map and the time taken to locate blind pairs, while at the same time preserving the behavioural integrity of the WAD. The use of an RMB options file permits the designer to vary RMB's processing, in order to achieve greater or lesser degrees of optimisation, or produce particular special effects. A full list of the available options, with a short explanation of the function of each, is given below. Detailed descriptions of the operation of each option (ordered alphabetically) is left to the next section.

NOTE: Options marked with & gained new syntax in v2.1. Options marked with + are new to v2.1. No options require the PERFECT option to function correctly any more. Options marked with ! can cause problems in combination with PREPROCESS.

   #          Marks a comment line in the option file
+  BAND       Makes bands of blindness/ safety
&! BLIND      Makes sector(s) blind (or partially so)
   BLOCK      Stops monsters seeing through a pair of specified lines
   DISTANCE   Specifies how far (on the ground) monsters can see generally
   DOOR       Specifies the max. # of doors monsters can see through generally
   EnMy       Marks start of options for a particular Doom1 level
&  EXCLUDE    Forces exclusion of view from one sector to another
+  GROUP      Merges sectors into one. (Sectors get the same REJECT maps)
&  INCLUDE    Forces inclusion of view from one sector to another
&  INV BLIND  Makes sector(s) long-sighted
&  INV SAFE   Makes sector(s) invisible to close monsters (but not far ones)
   LEFT       Makes a 2s line one-way see-through (from left to right)
 ! LENGTH     Specifies how far (by sector) monsters can see generally
   LINE       Makes a 2s line impossible to look through for monsters
   MAPxx      Marks start of options for a particular Doom2 map
&  NODOOR     Marks sector(s) as not being a door [used only with DOOR option]
   NOMAP      Removes the graphical display; reports progress as dots instead
+  NOPROCESS  Only applies special effects; no processing done. Very fast.
   ONE        Same as BLOCK, but only operates in one direction
   PERFECT    Generates a perfect REJECT map: forces processing of all sectors
+  PREPROCESS Groups sectors to gain processing speed. (The efficiency drops)
&  PROCESS    Forces processing of specified sector(s)
   REPORT     Reports all detected distances >= DISTANCE setting to file
   RIGHT      Makes a 2s line one-way see-through (from right to left)
&! SAFE       Makes sector(s) invisible to far monsters
+  TRACE      For debugging only: use is not recommended

INV is short for INVERT. Any option can be abbreviated to its shortest unique form. If you wish SAFE can be abbreviated S, as no other options start with S. Equivalently PREPROCESS can be abbreviated PRE, but not PR as PROCESS also starts with PR.

2.3.4 Processing time implications of RMB options

Because many of these options alter RMB's processing methodology, their use will have implications for the time taken by RMB to build the REJECT map. Below is a list of all the options, graded by their effect on the program's processing speed.

These options speed RMB up (greatest first):

    NOPROCESS [<Wadfile> [<Level id>]]
    PREPROCESS <Number>
    LENGTH     <Distance>
    DISTANCE   <Map distance>
    DOOR       <Number>
    GROUP      <Sector> <Sector list>
    BLIND      <Distance> <Sector list>
    LINE       <Line no>
    LEFT       <Line no>
    RIGHT      <Line no>
    BLOCK      <Line no> <Line no>
    ONE        <Line no> <Line no>

These options have no effect on speed:

    # <Comment>
    INCLUDE    <Sector> <Sector>
    EXCLUDE    <Sector> <Sector>
    SAFE       <Distance> <Sector list>
    INV SAFE   <Distance> <Sector list>
    INV BLIND  <Distance> <Sector list>
    BAND {SAFE, BLIND} <Distance> <Distance> <Sector list>
    INV BAND {SAFE, BLIND} <Distance> <Distance> <Sector list>

These options cause RMB to slow down (greatest last):

    REPORT     <Distance>
    NODOOR     <Sector list>
    PROCESS    <Sector list>
    TRACE      <Sector list>

Bear in mind that the longer RMB works, the greater the final efficiency of the REJECT table (and the better the final speed-up) is likely to be. Nevertheless, there will come a point where the additional return will not be worth the extra effort.

2.4 Miscellaneous

A few example WADs are supplied with the RMB package. Take a look at the .REJ files, and play the WADs to get some idea about what RMB can do. Not all possible uses has been covered in these WADs, but they give some idea about what RMB is all about. The WADs are all very small, so you won't be able so notice any speedup. As a rule of thumb, you need a WAD with more than 200 sectors and lots of monsters before you start feeling the speedup.


3.1 Explanation of argument types

The following terms are used to describe the arguments which RMB options take:

<Comment> Any text, terminated by end-of-line.
<Distance> A distance, measured in sectors, including the specified sector, so that 0 means "no distance", 1 means "this sector only", 2 means "this and all immediately adjacent sectors" and so on.
<Line no> The identification number of a 2-sided LINEDEF bordering two different sectors. e.g. a line with the 2s bit set and two sidedefs that point to two different sectors. You will find the linedef number in your WAD editor. (If yours won't tell you, you're using the wrong one!)
<Map distance> Distance as measured in Doom map co-ordinates. Opinions vary as to how this equates to distance in the real world: a good rule of thumb seems to be 1 map unit is equivalent to 2cm.
<Number> A positive integer.
<Sector> The identification number of a SECTOR, determined from a WAD editor.
<Sector list> A list of <sectors>, separated from each other by spaces and surrounded by brackets. e.g. (1 2 5 7 9)

3.2 Individual Option Details

This section contains full details of the operation of each RMB option, arranged in alphabetical order:

# [Comment] Syntax: # <Comment>

Lines in the options file which start with a # character are regarded by RMB as comment lines: the entire line will be ignored. Comments are terminated by an end of line and may contain any characters whatsoever. Use comments in your options file to remind yourself of what you are trying to achieve in the file, or to temporarily disable options in the file without deleting them.

BAND Syntax: BAND {BLIND, SAFE} <From> <To> <Sector list>

(The <From> and <To> part of this option are both distances by sector).

The BAND option is more complicated than the SAFE and BLIND options. If you haven't read about those yet maybe you should do that, and return here later.

The BAND option is used to create bands of blindness (or of safety). Each sector in the <Sector list> is processed separately with all sectors lying between <From> and <To> sectors away marked as BLIND to (or SAFE from) the sector being processed.

Applied to this map:

    |    :    :    :    :    :    :    :    |
    | 1  : 2  : 3  : 4  : 5  : 6  : 7  : 8  | (a ':' marks a 2s line)
    |    :    :    :    :    :    :    :    | (The numbers are sector numbers)

the option

BAND BLIND 3 5 (1 2)

will create two bands of blind sectors: all of those between 3 and 5 sectors from sector 1; and those the same distance from sector 2. In this example, this means that monsters in sector 1 will be unable to see players in sectors 3, 4 or 5; similarly, monsters in sector 2 will be blind to players in 4, 5 or 6. Note that the sectors at the <To> and <From> distances are included in the band.

The option

BAND SAFE 2 3 (1 2)

will create the same bands of sectors as before but will mean that a player in sector 1 or 2 will be safe from monsters in the appropriate band.

Any BAND option can also be inverted:


will make the specified sectors safe from anything outside the band; and


will make the specified sectors blind to anything outside the band. For instance, using:


will cause monsters in sectors 1 and 2 unable to see anything outside the band, making sector 1 able to see only sectors 3, 4 and 5, whereas sector 2 will be able to see sectors 4, 5 and 6 but nothing else.

BLIND Syntax: BLIND <Distance> <Sector list>

This is a similar option to the BLIND parameter in the EFFECT utility but with rather more flexible usage. It turns all of the sectors in the <sector list> blind for the specified <distance>. A value of 0 for <distance> will produce a sector in which monsters can see nothing at all. A <distance> of 1 prevents monsters from seeing out of the sector. With <distance> 2, monsters can see their own sector and all immediately neighbouring sectors, and so on.

Applied to this map:

    |    :    :    :    :    :    :    :    |
    | 1  : 2  : 3  : 4  : 5  : 6  : 7  : 8  | (a ':' marks a 2s line)
    |    :    :    :    :    :    :    :    | (The numbers are sector numbers)

the option

BLIND 3 (5 7)

will allow monsters in sector 5 to see up to 3 sectors each way (counting their own sector) i.e. sectors 3, 4, 5, 6 and 7 but not sectors 1, 2 or 8. In addition, monsters in sector 7 get to see into sectors 5, 6, 7 and 8, but not sectors 1, 2, 3 or 4.

This option is useful if you want to restrict monsters' viewing range in certain areas, to allow for low light intensities, perhaps; or just to prevent them from waking too soon.

The BLIND option can be prefixed by the option INV as below:

INV BLIND 1 (2 3 4)

While BLIND (without INV) makes monsters near-sighted or totally blind, inverting this with INV BLIND makes monsters LONG-sighted. This means that a monster in any of the sectors specified in <sector list> will only be able to see sectors beyond the specified <distance>. This means that where BLIND 1 <sector list> makes the monsters in one of the specified sectors unable to see anything but their own sector, INV BLIND 1 <sector list> will make them unable to see their own sector, but quite capable of seeing all sectors beyond it.

There may be occasions when you want to prevent a sector from seeing other sectors within a range of distances, say between 2 and 4 sectors distant. RMB allows you to achieve this effect by combining the BLIND and INV BLIND options in the following way: if you specify both INV BLIND and BLIND options for any particular sector(s) and the value you specify as the distance for the INV BLIND option is greater than that for the BLIND option, then RMB will blind the specified sector(s) from only those sectors located where the two distances overlap. For example, if you use


RMB interprets this to mean "make sector 1 blind to only those sectors which are closer than 4 but further away than 2". Note that this is a specific exception to the general rules about the combination of options which are set out in the next section.

An easier way of making the same would be to use the BAND option (BAND BLIND 2 4 <Sector list>).

In cases where BLIND and INV BLIND options affect the same sector and the INV BLIND distance is the smaller of the two, standard combination rules apply:


will be interpreted as "make sector 1 blind to sectors closer than 2 and to sectors further away than 4". Here, each option is applied just as would be expected. The same thing can again be achieved by

INV BAND BLIND 2 4 <Sector list>

BLOCK Syntax: Block <Line no> <Line no>

This option sets a block to any los-calculation that attempts to pass through both of the specified <Line no>'s. The ability to set such blocks is provided to compensate for RMB's over-cautious treatment of vertical differences between sectors (remember that it ignores height changes in its own los-calculations). Recall our earlier lift shaft? With the lift in the 'down' position, it looks like this (in side view):

                            4      5
                         |------|------|        Plain numbers identify
                         |         o   |        sectors;
                         |         -\  |
                         |          /\ |        Sector 4 is a lift in
                         |      |------|        the 'down' position.
                         |      |   ^
                         |      |   |
       1       2      3  |      |   example player
    |------|------|------|      |   position
    |                           |
    |                           |
    |                           |
          #0     #1     #2     #3      <- These numbers identify 2-s


Because of the relative floor and ceiling heights, sectors 1 and 2 cannot see sector 5 or vice versa. RMB cannot work this out from the level map, however, which looks like this:

    |      :      :      :      :      |
    |  1   :   2  :   3  :   4  :  5   |   where every sector appears to
    |     #0     #1     #2     #3      |   be able to see all others.
    |      :      :      :      :      |

If you want RMB to know about this particular blocked line-of-sight, you'll need to tell it. In this case, the block is between line #1 and line #3 (i.e. nothing to the left of #1 can see anything to the right of #3 and vice versa) and you would use the option


As already mentioned, hunting through your WADs for blocks such as this just to gain some playing speed is unlikely to pay off. The BLOCK option is useful for chopping short particularly long lines of sight, such as those identified for you by the REPORT option (see below); or for handling those areas where you want to make absolutely sure (as in the example above) that monsters don't see more than is good for them (or good for you, at any rate!)

[You may be interested to know that the Doom game engine does not seem to know too much about vertical blocks such as these either: if you'd like to see an example, check out the accompanying RMBTESTS.ZIP].

Obtain the <Line no> identification of the lines you wish to BLOCK from your WAD editor.

Note that for a BLOCK to be successfully specified with this option, both of the specified lines must be on inter-sector boundaries. Internal lines, acting as triggers or monster-blockers, cannot be specified, as they occupy only one sector and the REJECT map only contains information about intersector sight-lines. If you need to set a block at a particular line within a sector, you will need to divide the sector into additional sectors using your WAD editor, before applying RMB.

DISTANCE Syntax: DISTANCE <Map distance>

The DISTANCE option allows you to set a limit on how far monsters can see generally, in the WAD you are processing: sectors further apart than the specified distance will not be able to see each other (subject to some conditions, set out below). DISTANCE is similar in operation to the LENGTH option, but it takes a distance parameter specified in Doom map units, rather than sectors: this is usually the better way to limit the lines of sight.

The distance being specified is the maximum distance by which you want sectors in sight of each other to be separated. It is important to realise, however, that RMB will not start to check on whether or not to apply any DISTANCE limitation until the sectors being examined are three or more sectors removed from each other, thus:

    |      :      :      :      :      :          :
    |  1   :   2  :   3  :   4  :  5   :     6    :  7
    |      :      :      :      :      :          :
           <------d4----->                d4 = distance between sector 1 & 4
           <----------d5-------->         d5 = distance between sector 1 & 5
           <--------------d6----------->     etc.

Here, sector 1 will be marked as seeing sectors 2 and 3 regardless of any DISTANCE option setting. Along any sight-line from sector 1 (and there is only one here), subsequent sectors will be considered until the inter-sector distance (here d4, d5, d6 etc.) exceeds the value specified in the DISTANCE option. Sectors within the distance are within sight, those further away are marked as being out of sight. In the above example, if we take each dash (-) on the map to equate to 10 Doom map units, then the distances between sector 1 and all of the other sectors shown are:

d4: 140
d5: 210
d6: 280
d7: 390 etc.

If the option


was specified for this level, then sector 1 would be able to see all other sectors as far as sector 6. Sector 7, however, would be too far away and consequently would be marked as out-of-sight. A DISTANCE setting of 130 would prevent sector 1 from seeing as far as sector 4. There is no setting of this option that you could use to prevent sector 1 from seeing sectors 2 or 3.

To gain some feel for how far any distance setting actually is, bear in mind that a normal door is 128 units wide. Another good rule of thumb, which many designers use, is that one Doom (horizontal) unit equates to about 2cm in the real world. A setting of


would therefore prevent monsters from seeing between any sectors that were more than (approx.) 20 (virtual) metres apart at their closest point (provided there were at least two sectors in between).

Use this command to increase the efficiency of the REJECT map, by preventing monsters from seeing great distances. Don't use it, of course, if you have areas of your WAD that rely for effect on monsters being able to see long distances: like in E2M3 of DOOM.WAD, for example.

Take care also not to confuse this option with LENGTH.

DOOR Syntax: DOOR <Number>

This option makes RMB attempt to recognise sectors which are doors and then adjust the REJECT table to prevent monsters from seeing through more than the specified <number> of doors at any one time.

The option is provided to allow an increase in the REJECT map efficiency by utilising the fact that it is usually hard for monsters to see through a long string of doors (more than 4 or 5, say) because they are unlikely ever to all be open at the same time. Choose the value with care: 5 is usually safe; 3 can be: you may have to experiment to find the best setting for your WAD. Remember that monsters can open some doors. Remember too that during Death Match or Co-operative play there may be up to four players all capable of opening doors simultaneously. (I didn't say it was likely, I merely said it could happen!)

Sectors are identified as doors by RMB if they have their floor and ceiling heights set to the same value. If you have sectors set this way that you don't want RMB to treat as a door for the purposes of sight-line blocking (because it stays open, for example), you can use the NODOOR option (see below) to tell RMB which sectors to ignore.

EXCLUDE Syntax: EXCLUDE <Sector list1> <Sector list2>

This option allows you to specifically exclude particular inter-sector lines of sight. Its action is to make it impossible for monsters in any of the sectors in <Sector list1> to see any of the sectors in <Sector list2>. Note that EXCLUDE operates only in one direction (affecting just a single bit in the REJECT map for each sector pair) and that it overrides ALL other option settings for the specified sight-line.

EXC can be used to make small adjustments after the wider application of other options, or to make minor modifications to a REJECT table. It is particularly useful for setting small 'safe' areas within larger rooms. The option:

EXCLUDE (1 2) (4 5)

will exclude all the LOS pairs: (1,4) (1,5) (2,4) and (2,5).

GROUP Syntax: GROUP <Sector> <Sector list>

The group option is used to make RMB consider multiple sectors as one. When the following option is used:

GROUP 5 (2 4 7)

sectors 2, 4, 5 and 7 will be considered by RMB to be one big sector. This will speed up RMB, as it now only needs to process one sector in the place of four! The only disadvantage is that the efficiency of the generated REJECT map might drop. If, for instance, in the above example only sector 4 is able to see sector 6, this will be copied, resulting in sectors 5, 2 and 7 having a zero in the REJECT map at position 6, too. Thus, the number of bits set will drop by three. Provided only neighbouring sectors are grouped, this loss of efficiency should be very small. Whether you notice this or not in the final WAD will obviously depend upon the number and distribution of monsters and the layout of sectors.

Once sectors have been GROUPed using this option, they will be treated as one sector for all of RMB's processing. Options cannot be applied to individual members of the group, with the exception of the INCLUDE and EXCLUDE options.

If you want to apply special effects to the group as a whole, you must refer to the single sector into which you have grouped all of the others. This is the number specified in the single <Sector> parameter: 5, in the example above.

This can be used when you want multiple sectors to be able to see exactly the same things. If for instance sectors 2, 4, 5 and 7 are ambush spots, and you want the monsters in these sectors to wake up when the player enters sector 10, you can give the following options:

        GROUP 5 (2 4 7)
        BLIND 0 (5)
        INCLUDE 5 10

This will do the trick: the only thing seen from sectors 2, 4, 5 and 7 now will be sector 10. As a further example of the processing of grouped sectors, consider the following options:

        GROUP 5 (2 4 7)
        BLIND 1 (5)

Here BLIND 1 means that the grouped sector 5 will be able to see itself, but what does that mean? It means that all the sectors in the group: i.e. sector 2 can see sectors 2, 4, 5 and 7.

INCLUDE Syntax: INCLUDE <Sector list> <Sector list>

This option allows you to force particular sight-lines to be examined by the game engine at game-time. It marks it as feasible for monsters in the first <Sector list> to see a player in any of the second <Sector list>, no matter what all the other options say. INCLUDE overrides all other options except EXCLUDE. The option:

INCLUDE (1 2) (5 6)

Will include the following LOS in the REJECT map: (1,2) (1,5) (2,5) and (2,6).

It can be used to make special effects like this:

Blind a sector completely with BLIND 0. Put a lot of monsters in it, then make a platform in sight of the blinded sector. Use the INC option to make the monsters able to see the platform and nothing else. If it is difficult for the player to see from the platform to the blinded sector, the player will be surprised when he is suddenly attacked...

"I stepped onto the platform and took the key. There was no sound of doors opening, so I was home free... suddenly, the room was flying with fireballs. Where the <censored> did those imps come from?"

INVERT BAND Syntax: INVERT BAND BLIND <From> <To> <Sector list>
INVERT BAND SAFE <From> <To> <Sector list>

See the BAND option for details of the INVERT BAND option.

INVERT BLIND/SAFE Syntax: INV BLIND <Distance> <Sector list>
INV SAFE <Distance> <Sector list>

See BLIND and SAFE for details of the INVERT option.

LEFT Syntax: LEFT <Line no>

This option makes a two-sided LINEDEF, specified through its <Line no>, into a line through which monsters can only see from its left side. This option is useful if you have a wall (or curtain) that has a solid texture on one side but not on the other and you want monsters to respond logically to it. (Normally, monsters can see through all 2-sided LINEDEFs, irrespective of their textures.)

Note that for this option to be applied successfully, the specified line must be on an inter-sector boundary. Internal lines cannot be specified: if you need to apply this type of block to a particular line within a sector, you will need to divide the sector into additional sectors along this line using your WAD editor, before applying RMB.

LENGTH Syntax: LENGTH <Distance>

The LENGTH option allows you to set a limit on how far (in terms of sectors) monsters can see generally: sectors further apart than the specified distance will not be able to see each other. The <Distance> limit is the number of 2- sided LINEDEFs through which monsters can see.

Use this command to increase the efficiency of the REJECT map by preventing monsters from seeing too many sectors ahead. Use it with care, however. A setting of 20 is often safe: any lower may make monsters behave strangely - if you want your monsters to be able to see from the top to the bottom of a flight of stairs, for instance, you must allow sufficient sectors in the LENGTH option to cover the entire staircase. For most WADs, the DISTANCE option gives better (more realistic) results.

LINE Syntax: LINE <Line no>

This option makes it impossible for monsters to see through a 2-sided line at all. This is useful if you have such a line with texture on both sides, so that the player can't see through it. Normally monsters can see through any 2-sided line: with this option you can prevent them from doing so.

Note that for this option to be applied successfully, the specified line must be on an inter-sector boundary. Internal lines cannot be specified: if you need to apply this type of block to a particular line within a sector, you will need to use your WAD editor to divide the sector into additional sectors along this line, before applying RMB.

NODOOR Syntax: NODOOR <Sector list>

This option allows you to specify which sectors should not be considered to be doors, when processing the DOOR option. (See DOOR for details.) Obviously, there is only any point specifying sectors that could be mistaken for doors (by virtue of them having their floor and ceiling at the same height).

RMB does not consider doors unless the DOOR option is used, so the NODOOR option does nothing unless a DOOR option is in effect.


This option instructs RMB not to display the graphical view of the level being processed. Instead, the number of the sector being processed is shown, followed by a dot as each sector adjacent to the current sector is processed. In effect, a new dot is printed each time a line would have changed to yellow on the map display.

It takes exactly the same time to process a wad in the graphics mode as it takes in the text mode.

When NOMAP is used you can start the program without being in the same directory as RMB.

NOPROCESS Syntax: NOPROCESS [<Wadfile> [<Level id>]]

The NOPROCESS option allows you to add just a few special effects to your WAD's REJECT map, without having to wait for RMB to complete all other line-of-sight calculations. You can use this option if you only want to add special effects and are not interested in optimising the REJECT, or if you want to add some more effects to a WAD that has already been optimised.

If you specify NOPROCESS, the only other options that will have any effect are:


The NOPROCESS options is provided for reasons of speed. If all you want to do is to add a few simple special effects, and you don't want to optimise the REJECT structure NOPROCESS will do the job for you.

If NOPROCESS is used with no arguments, your source WADfile's current

REJECT map is loaded as the starting basis of the remaining option processing.

If you specify a <WADfile> for this option, the starting REJECT will be read from this file, rather than your source WAD. It makes no sense at all to load a REJECT map from a WAD that is not related to your source WAD, of course. If the REJECT map in the specified file is not of the correct size, this option will be ignored and the whole WAD processed from scratch.

RMB works much faster with the NOPROCESS option turned on. The only problem is that the REJECT map will not be optimised in any way. The only thing that happens is that the special effects will be added. If you have just built the REJECT map and you find that you need just one more INCLUDE for your special effect to work, specifying NOPROCESS might be the thing to do!

If you are working with a (big!) WAD and want to use RMB every time you have made changes, you could make a batch file like this:

EDITOR thefile.WAD
RMB thefile.WAD tmp.wad
DOOM -file tmp.wad

Maybe you would also like to run a nodebuilder, in which case you just run it before RMB. (Some nodebuilders destroy the REJECT map). In your option file you can now specify:


This means that the REJECT map previously built and saved in tmp.wad will be loaded and used to apply RMB's special effects quickly. It is a little dangerous to use this scheme, as RMB will not be able to detect a change in the WAD, if the number of sectors hasn't changed. If you have moved some lines around changing the sector pairs that can see each other, maybe you should rebuild the REJECT map. Rebuilding can easily be achieved by deleting the tmp.wad file, or by renaming it. That would force RMB to rebuild from scratch the next time you run the batch file.

For multilevel WAD's you might need to provide the NOPROCESS option with the extra <level id> parameter. For example if you are editing a doom 2 multilevel wad this might make sense:


ONE Syntax: ONE <Line #1> <Line #2>

Whereas BLOCK blocks a line-of-sight both ways across two specified lines, the ONE option sets a block in one direction only: from <Line #1> to <Line #2>. This is useful in areas where you would ordinarily use a BLOCK option, but you know that there is already some other one-way block in operation (a RIGHT or LEFT, say) somewhere between the two BLOCK lines, making RMB's further blocking of both directions superfluous. Reducing such extraneous operations will increase the speed of RMB's processing.

Note that for a block to be successfully specified with this option, both of the lines must be on inter-sector boundaries. Internal lines, which act just as triggers and monster-blockers, cannot be specified: if you need to set a block at a particular line within a sector, you will need to use your WAD editor to divide the sector into additional sectors along that line, before applying RMB.


Ordinarily, RMB will treat all sectors that are totally enclosed within another sector as part of the enclosing sector (provided they have no 1-sided LINEDEFs). In most WADs, this greatly cuts down the number of sectors that RMB needs to consider. It also leads to a less than perfect REJECT map: use the PERFECT option to prevent RMB from taking this processing short-cut and make it consider all sector-to-sector sight-lines. Be prepared for long processing times, however, if you have a large WAD.

Note that from v2.0 of RMB, all sectors referenced in a SAFE, BLIND, BLOCK, ONE, LEFT, RIGHT or PROCESS option will be processed, regardless of whether PERFECT has been specified or not. However, sectors that are internal to the sectors referenced in the SAFE or BLIND options will not be treated separately from their enclosing sector, unless PERFECT has been specified or PROCESS has been used for these specific sectors. If you don't use PERFECT or PROCESS, any sector specified as SAFE, say, will have all its internal sectors marked safe as well. Don't be tempted to use PERFECT just to prevent the SAFE and BLIND options from working in this way over a small area, especially if you are processing a larger WAD. You will add a large processing over-head to prevent only a small number of unwanted effects: it is better to identify the areas which will be treated incorrectly (to your way of thinking) and force their inclusion in RMB's processing with a PROCESS option (see below). Using PERFECT on large WADs can add considerably to RMB's processing time for very little gain in REJECT efficiency.

You may find it beneficial to think in terms of rooms, rather than sectors when planning and applying your special effects: in the default mode of operation (i.e. without PERFECT) if you apply the SAFE option to a sector that encloses other sectors (a room), you will make all the 'decorational' sectors in that room safe too: this is usually what is wanted. Consider this room, for example:

  Sector 12 is main room;
      :                                    :      v. low light levels
      :   o.......o       o.....o   o...o  :
      :   :       :       :     :   :   :  :      sectors 13, 14, 15 are
      :   :       :       :  14 :   : 7 :  :      platforms in the room
      :   :   13  :       o.....o   o...o  :      also at v. low light
      :   :       :   12                   :      levels;
  10  :   :       :       o.....o   o...o  : 11
      :   o.......o       :     :   :   :  :      sectors 7, 8 are
      :                   :  15 :   : 8 :  :      areas brightly lit.
      :                   :     :   o...o  :
      o.....o             o.....o          :
      :  9  :                              :      sector 9 = high ledge

You may decide that because the room is very dark, the player should not be seen there easily and you would like it to be safe from attack from monsters who aren't in it: in sectors 10 & 11, for instance, or off to the east and west, somewhere. You would therefore use the option SAFE 1 12. Without PERFECT, the resulting REJECT table looks like this:

           7   8   9  10  11  12  13  14  15     Note that all other bits in
        +-------------------------------------   the player sector columns
    7   |  0   0   0   0   0   0   0   0   0       7, 8, 12, 13, 14 & 15
 M  8   |  0   0   0   0   0   0   0   0   0            will be 1's.
 O  9   |  1   1   0   0   0   1   1   1   1
 N 10   |  1   1   0   0   0   1   1   1   1
 S 11   |  1   1   0   0   0   1   1   1   1
 T 12   |  0   0   0   0   0   0   0   0   0
 E 13   |  0   0   0   0   0   0   0   0   0
 R 14   |  0   0   0   0   0   0   0   0   0
   15   |  0   0   0   0   0   0   0   0   0

You should be able to see that this makes all sectors inside sector 12 (as well as sector 12 itself) safe from attack from monsters outside the room. [Note that the platform, sector 9, has not been included in the room here: it has a 1-sided LINEDEF, as well as a connection with another sector and therefore is not an enclosed sector.] Within the 'room' (i.e. the main sector and all its enclosed sectors), though, monsters can see everything.

If the PERFECT option had been specified, on the other hand, the REJECT map would have looked like this:

           7   8   9  10  11  12  13  14  15
    7   |  0   0   0   0   0   1   0   0   0    Note: all other bits in
 M  8   |  0   0   0   0   0   1   0   0   0     player sector 12 will
 O  9   |  0   0   0   0   0   1   0   0   0           be 1's.
 N 10   |  0   0   0   0   0   1   0   0   0
 S 11   |  0   0   0   0   0   1   0   0   0
 T 12   |  0   0   0   0   0   0   0   0   0
 E 13   |  0   0   0   0   0   1   0   0   0
 R 14   |  0   0   0   0   0   1   0   0   0
   15   |  0   0   0   0   0   1   0   0   0

Notice that here none of the enclosed sectors act as part of the larger 'room' any more: no longer are they safe (from anything, anywhere) and monsters in them will behave oddly, in that they can no longer fire into the main sector.

By and large, you will usually find that the default operation of RMB (i.e. without PERFECT) will give more 'desirable' handling of the SAFE and BLIND special effects.

If you then want certain enclosed areas not to inherit the general level of safety of the overall room, use a PROCESS option to prevent it. (See below)


If you think RMB is slow, PREPROCESS is the option for you. PREPROCESS will group neighbouring sectors almost at random. The number you specify is the maximum number of sectors you want in one such group. The reason for grouping sectors is to gain processing speed. A setting of


means that RMB only needs to process half as many sectors. When there is no option file found, RMB applies a default preprocessing with 4 sectors in every group. This causes RMB v 2.1 to become a lot faster than v 2.0, as this type of preprocessing was not performed by version 2.0. Naturally grouping like this can cause some troubles for your special effects, so the default preprocessing is disabled when an option file is detected and it is left up to you to decide if it's safe to PREPROCESS. It is always safe to use PREPROCESSing when you don't use any options with a length (by sector) parameter above 1. This means that

BLIND 1 (2 3)

is OK to use together with PREPROCESS, but

SAFE 2 (2 3)

isn't (because 2 is used as a length by sector parameter).

Note that the options LENGTH, SAFE and BLIND are the ones that specify loslengths by sector. You need to use
PREPROCESS with care in conjunction with these options.

PROCESS Syntax: PROCESS <Sector list>

This option forces RMB to process fully the sectors specified in the <Sector list>, regardless of whether they happen to be contained wholly within another sector or not. The option is designed to force processing in areas where you are applying special effects, where you wish to prevent the grouping of enclosed sectors with their surrounding sector, or where you need rigorous optimisation of the REJECT map. Naturally, its use is entirely superfluous if you also use the PERFECT option.

In the example room used to demonstrate the PERFECT option above, it would make sense for the player to come under fire from monsters outside the room if he stepped into the brightly lit areas (sectors 7 and 8), because he would now become more visible. To achieve this, simply use PROCESS 7 8 in the options file: this will result in RMB processing these two sectors separately from the rest of the room. In effect, the bit settings for sectors 7 & 8 shown in the second of the two REJECT maps (the PERFECT version) will be substituted for those shown in the earlier map, and the player will now be open to attack from all monsters while in the two brightly-lit areas of our room. Of course, this will also mean that monsters in sectors 7 & 8 will now no longer be able to see into the main 'room' (because these sectors have no been processed as if they were separate from it). If you don't think that monsters in these sectors will be dazzled by the extra light and would like them to be able to fire into the room, you'll need to use a couple of INC options to override this aspect of the PROCESS effect.

REPORT Syntax: REPORT <Distance>

If this option is used, a file with the same name as the WAD file but with the extension .RPT is generated. After the execution of RMB, this file will contain a list of all sector pairs that are separated from each other by a distance in excess of that specified (measured in sectors) and are also in line of sight of each other. This is useful for the identification of areas where sight-lines would seem to be excessively long. In practice, such lines of sight are more than likely blocked by differences of floor and ceiling height, or by several doors. The REPORT file will then help you identify suitable places to apply a BLOCK.

Using a REPORT <distance> factor greater than any distance specified in a LENGTH option would be a waste of time, as RMB will already have applied a BLOCK itself. It is often a good idea, though, to use REPORT and LENGTH together, with the same <distance> value. A value around 20 is generally a good one to use (although see comments on LENGTH values, above.)

RIGHT Syntax: RIGHT <Line no>

This option works exactly as LEFT, except that it allows monsters to see through the line from its right side only. See LEFT for details.

SAFE Syntax: SAFE <Distance> <Sector list>

This option operates much as the SAFE parameter in the EFFECT command, but with rather more flexible usage. The <Distance> parameter allows you to specify how close (in sectors, of course) monsters must be in order to see into the specified sector(s). Distance is reckoned exactly the same way as for the BLIND option: SAFE 0 indicates that a sector is only safe from within itself; SAFE 1 sets a sector that is unsighted from all of its neighbours but can be seen by monsters actually in the sector, and so on.

The SAFE option can be prefixed by the option INVERT as here:

INVERT SAFE 1 (2 3 4)

This option allows you to specify sectors which are safe from the attention of monsters within the specified <distance> but which will still suffer attacks from monsters further away. Because it is in the nature of monsters to always try to move closer to the player, this will have the effect that the monsters will disable themselves as they move closer to INVERT SAFE sector(s)!

INV SAFE and SAFE can be combined to cover ranges of distances, in the same way as INV BLIND and BLIND: see the BLIND option for more details.

TRACE Syntax: TRACE <Sector list>

The use of this option is not recommended. It is mainly used for debugging purposes, to see if RMB processes correctly. TRACE only works when the graphic is enabled, and it displays the LOS being processed. Every time the user presses a key, RMB takes another step in its processing. This is very slow, so don't use it unless you are very interested in the way RMB works. While tracing, the available memory is displayed in the top left corner (the number to the right of the three numbers).

3.3 Combining Options

Most RMB options can be applied quite independently of other options. It is possible, however, for conflicting options to be specified for individual sectors and it is important to understand how RMB resolves these conflicts.

In cases where an attempt is made to apply the same option to any particular sector in different ways, as here, for example:

SAFE 2 3
SAFE 0 3

it is only the last version that is applied. In this example, the SAFE 2 3 option is never used. This is the only case where the order of options in an options file is significant.

Generally, if different options are applied to the same sector in such a way as to produce a conflict, both options will be applied fully with any losblocks created by one of the options preserved, whatever the other options say.

In this example:

SAFE 1 3

the BLIND option will blind sector 3 from itself despite the SAFE option implying that it shouldn't. Reversing these two options in the options file would make no difference to the resulting REJECT map.

There are a number of specific exceptions to this general rule:

I. the BLIND and INV BLIND options can be combined in a special way to produce 'bands' of blindness: this occurs when the distance parameter supplied to INV BLIND exceeds that supplied to BLIND. See the description of the BLIND option for details. From version 2.1 it is now possible to do the same thing with the BAND option, which is recommended.

II. the SAFE and INV SAFE options can be combined in the same way as BLIND and INV BLIND: see the description of the SAFE option for details.

III. the BAND SAFE option overrides any other SAFE option for the sector in question. And BAND BLIND overrides any other BLIND option for the sector. But BLIND or SAFE can't override BAND BLIND/SAFE (respectively).

IV. the INC option overrides all other options, except EXC.

Sometimes it is a good thing to be able to override options. If you have an option file for a multilevel WAD with a general part containing a few general options, you can override some of the general options in the specific level parts. Options that can be overridden are:


This means that if you apply

SAFE 0 (1 2 3)
SAFE 1 (3 4 5)

The safe parameter for sector 3 will be overridden, and sector 3 becomes SAFE 1

The BAND <SAFE/BLIND> option must NOT be used in conjunction with a <SAFE/BLIND> option for the same sector. The following is illegal:

BAND BLIND 2 4 (3 5)
INV BLIND 0 (1 5)

Here a BLIND option is used twice for sector 5, which can cause surprising effects, as BLIND is not supposed to be combined with BAND BLIND for the same sector! (The same applies to SAFE).

BAND BLIND can, of course, be combined with SAFE and vice versa (as well as for the same sector)


RMB won't run

Check that you have given the right path to the RMB.EXE, and that the file you are trying to process exists. If RMB still doesn't run try to make an option file for your WAD, with only one option: NOMAP. An option file like that will simplify the way RMB executes, and maybe it will run.

Also RMB might not run if your WAD has more than 1200 sectors. The precise upper bound before RMB get memory problems is unknown because WADs with more than 1000 sectors are rare. If you suspect that RMB has memory problems try the TRACE <Sector list> option to see how much free memory is left.

RMB doesn't display the graphics

This is normally because RMB can't find the .BGI files needed, or because the .BGI files doesn't work with your graphics card. In the first case try to set the environment variable RMB:

set RMB=c:\RMBdir
(Or wherever you want to store the BGI files)

If RMB still won't display the graphics, you might as well make an option file with the NOMAP option in it, and get the ASCII output instead.

The troubleshooting section doesn't help me with my problem

Send me a mail! My internet address is: hykkelbj@daimi.aau.dk. My snail mail address is:

        Jens Hykkelbjerg
        Haslehoejvej 5 b
        8210 AArhus V.
        Denmark (DK)

But who wants to waste money on snail mail?


This program is copyright of its author, Jens Hykkelbjerg. This documentation is copyright of its authors Jens Hykkelbjerg and Steve Benner.

Doom and Doom 2 are Id software products, and are not free of charge.

The credit for any WADs mentioned in this text goes to the respective authors.

This program and its documentation is supplied completely free of charge. The program and its documentation may be freely distributed, providing that it is intact and has not been modified in any way. The program, documentation or parts thereof may NOT be used for commercial purposes or financial gain or be included in commercial packages (including shareware releases). You may not charge for handling or distributing this program, its documentation of any part thereof.

The author accepts no responsibility for ANYTHING that may happen as a result of using this software. If your computer mutates into something large, pink and savage, that's your problem.


This software was written by Jens Hykkelbjerg: email: jensh@cybernet.dk

I was a student on The University of Aarhus when I wrote RMB. Today I work at a Danish Company called TeleDanmark. RMB was inspired by a discussion on the Doom-editing list (long may it run) and written entirely from scratch using Borland's Turbo Pascal 6.0.

I use different editors, ZenNode and WinTex for my own WADs. I recommend the use of a rule checker like the one in DEU5.21 before using this program!

The manual was written by Jens Hykkelbjerg and Steve Benner: email S.Benner@lancaster.ac.uk

Steve is a computer support officer for the Environmental Science Dept at Lancaster University, UK. He has been playing computer simulations for more years than he likes to admit. He uses WADED for his WADs but wouldn't want to start an argument over it!


"The Unofficial Doom Specs" was a great help in the production of this program: without it, this program could never have been written.

Thanks also to Steve Benner for mangling, mutilating and generally hacking this manual into its current form: if it's too long now, blame him. Send any moans, grumbles or suggestions for improvement that you may have about the documentation to him: email: S.Benner@lancaster.ac.uk

Jens Hykkelbjerg / Steve Benner
25 Jan 95