The ethics of decompiling maps

So, I've written a bsp decompiler. So far, it's pretty useful for
looking through maps and seeing how various entities are used (this is,
in fact, exactly what I wrote it for).

It's brushwork production is not very good. Texturing is OK, but the
brushes are sort-of faked. (Technically, it turns every face in the map
into a thin brush, kind of like a facade - it doesn't try to
reconstruct the original brushes in any way). It looks reasonable,
enough to see where everything is in Hammer, but you'd have a hell of a
time editing or recompiling anything.

Because of this, until now I've not seriously worried about people
using it to rip-off other people's maps. It's just too much work to do
anything, you'd practically have to remake every brush on the map.
Despite some head-banging messages I've seen on some forums and
received by email (d00d, will you send me the vmfz for de_dust? I want
to make some kewl changez!), I don't regret releasing it.

But now I've found a different way of decompiling. It turns out that
damn-near everything you need to reconstruct the original brushes is
stored in the bsp. (I still haven't decoded displacement surfaces yet,
and there are some difficulties with brush entities, but I will
probably be able fix them.)

I haven't release a version that uses this method yet, and I'm not sure I want to. It's just a bit too
good - it recovers almost everything, clip brushes, hint placement,
detail brushes, etc. Even brush faces that are normally culled away. Some things get lost, but you could definitely use
the output to recompile a map that was almost identical to the original.

So, the question is, do I release this? There are some good,
experienced mappers here (and the forum is much more mature that some
other mapping forums, which is why I'm asking here). Would you prefer
not to see such a decompiler? Do you think what's released so far is
bad enough already? Or don't you care?

One option I've thought of is releasing it, but adding the ability of a
map author to add something to a map that disables decompilation (using
my decompiler, anyway). There are several things the program could
check for that would be hard for someone to get around. This is easy to
do, but wouldn't prevent rip-offs of already exisiting maps.

Bear in mind that it's not particularly difficult to write a decompiler

• almost everything you need to know is in one .h file in the SDK

source. Someone is likely to write another one eventually, even if I
stop production of the current one.

Anyway, let me know your thoughts, folks.

What about it looking for a Info_point entity called No_Import?

And not working if it finds it?

I'd say yes. I would like to decompile some maps to see entity setups.
Other people may try to ripoff peoples maps, but they won't get far.

I think that the only legitimate reason for decompiling is to see how someone created a particular effect. However, this principal could reasonably be extended to the placement of hint brushes and such as well as entity setups. I say release it. If some scumbag wants to steal peoples work with it, that isn't your fault. I believe that such a program would have enough legitimate uses to compensate for any abuses that it might lend itself to.

What about it looking for a Info_point entity called No_Import?

And not working if it finds it?

Something like that, or maybe a cetain property set in Worldspawn, or a
certain (unusual) texture being used, or even a particularly shaped
brush somewhere in the map. The last is the best, because it can't be
gotten around without practially writting your own decompiler. The
other methods, someone could easily edit the bsp to delete the "don't
decompile" tag, given a little ingenuity.

This would be helpful. When I was starting out and didn't know
how to use a spotlight in HL1, I used BSP>MAP to take a look at
datacore. It also gave me the names of textures that I liked but
couldn't find through the browser.

Of course some idiot or two will try and steal maps and whatnot, but
that's why you put in a disclaimer saying you will find and kill anyone
who steals or builds on your map. Disclaimers make it not illegal.

Personally I say go for it, and don't concern yourself with the
implications in the hands of idiots and ripoff merchants, trying to
sell someone elses maps off as their own. I don't think here is the
correct place to be asking whether or not to release a decompiler, as
generally decompiling is a taboo in the mapping world. I don't know
about the legalities, and I'm not sure that the very mention of the
subject won't be frowned upon by the moderators of this forum.

Decompiling, like dressing up in your mothers clothes and prancing
around is a shameful thing that we've all done but aren't proud
of...errr...ummm.... :biggrin:

Bear in mind that it's not....

That typo made me chuckle btw. :biggrin:

The ethics of decompiler can be analogized to knife manufacturing. People may use fruit knifes as weapons, but does it mean that the world should stop making knifes?

Since the decompiler clearly has legitimate uses, it should not be banned completely. In fact, it may be a very useful tools for new mappers to learn how to construct things.

no

We, the more experienced mapper know why we would use something like this. We want to know how the pro's do things.

But that is half the fun, solving complex problems, finding ways to create diffrent things.

Think of the horrible crap that some of these map makers would
create. I rember a remake I once played of dust2, the newbie who
decompiled it just cut holes in walls and made tunnles going all over
the place. This is not somthing that the public should get to
use! Not only becuase they would be free to steal parts of
anyone's map but becuase they would ruin maps that others spent hours
apon hours making.

These weekend mappers dont seem to understand that the layout of pro
maps isn't just tossed together over night. They would destroy
thousands of hours of hard work.

Think of every kid out there who says "man it would be so leet if there
was a passage through this wall in dust2" all he would have to do is
fire up the decompiler and use the carve tool to pop a nice little hole
in there.

I think there are already enough unoriginal maps out there, too many
copys and clones. Do any of you really want see 15 diffrent maps
that all have the same stolen brus work? Even worse, would you
want some one to take a part of your map that you spent countless hours
working on and just copy and paste it into your map?

Then... on the other hand, some one else will come up with one of these
sooner or later. Might aswell get yours out there first, at least
you could add a disclaimer or warning about stealing other people's
maps.

/rant

I'd say the only way you could sleep easily at night about decompiling
is if it was totally on a look-but-don't-touch basis. If the decompiler
deliberately messed up some geometry enough that the map was totally
unsalvagable, bar looking at entity setups etc. then that would stop
most thieves, since, if they can't be arsed making it, they can't be
arsed fixing it up. :smile:

Would this still work with on maps optimized with those tools released about a year back that I completely forget the name or author of? The tools would cull a whole bunch of the unimportant information from a map in order to reduce filesize and prevent hitting certain imposed limits on HL1 maps (planes specifically).

By the way, UT map formats allow anyone who has a map to view the source, make changes and recompile as they see fit. There are many junk copy maps out there, but not so many as HL. I am not saying whether this is due to the lost allure of doing something unethical or the fact that their community consists of more hardcore gamers and less lame people (certainly when compared to Counter-Strike) or some other reason entirely. It is frowned upon and modified maps certainly don't get the distribution that some of the de_dust modifications do. What I will say is I have seen very little incident of work being stolen and passed off as someone else's. People notice. I would venture to guess that having just a few monolithic review sites instead of the spotty downloading propositions HL has offered certainly plays a part in this.

Has any one here seen a decompile that is actually played on servers?

its becaus edecompiles are ussually by ultimate noob mappers, and the recompiles suck any way. SO release it, no recompiled map gets far.

that could be one way of looking at it, mephs, but i don't doubt that someone who takes more pride in or is more protective of their entity setups, would argue the point.

the idea that you could put a particularly shaped brush in the level to stop a decompile sounds good, but if you intend to use this, then i suggest uploading a prefab of this shape as soon as possible, so that people working on maps atm can include it.

You missed what he was saying, rs6. Previously, recompiling was just not feasible for creating real maps. This is why you didn't see many true recompiles played (although there were more than enough from-scratch imitations and entripped screw arounds out there anyway). He has discovered a new way to decompile that WILL restore the source. The ramifications of releasing a program like this are not to be measured by a linear extrapolation of what has happened in the past.

DrGlass:

Think of every kid out there who says "man it would be so leet if there
was a passage through this wall in dust2" all he would have to do is
fire up the decompiler and use the carve tool to pop a nice little hole
in there.

Eeek. While that idea makes me cringe, I'm actually somewhat less
worried about that sort of thing. If somebody rips off dust or de_aztec
or cs_italy, everyone will know exactly what they've done. I'm more
concerned that someone will make a good new map, and someone else
ripping it off, changing a few things, and calling it their own. (And
nobody realising what they've done).

Mephs:

If the decompiler
deliberately messed up some geometry enough that the map was totally
unsalvagable bar looking at entity setups etc.

That's essentially what the released version does at the moment. The
entities are fine, but the brushwork is not good. The major drawback of
the current version is that it can be slow in hammer, due to all the
extra brushes created.

I am considering deliberately breaking the geometry a little so it
wouldn't compile, but ironically it's quite difficult to deliberatly
create a brush that will load in Hammer but won't compile properly.

One way to do it would be to randomize some vertices slightly, enough
that the decompiled brushes no longer fit together properly. Then
anyone recompiling would have a hell of a time fixing leaks,
microbrushes, etc.

Anyway, thanks for your input, guys. I am currently leaning towards
releasing, but including a way that a mapper can flag a map as
non-decompilable.

(Edit: yes, if I do it as a special brush, I'll have a prefab available that anyone can add to their map)..

Would this still work with on maps optimized with those tools
released about a year back that I completely forget the name or author
of? The tools would cull a whole bunch of the unimportant information
from a map in order to reduce filesize and prevent hitting certain
imposed limits on HL1 maps (planes specifically).

Yes, this is one way of defeating the decompiler. It worked for HL1,
and I'm sure that someone will eventually write one for HL2, too.
Unless the Source engine needs the info somehow, there seems to be a
lot of info in the .bsp that's not needed to usually display the map.

In particular, the HL2 compile tools store every original brush and
plane that was in the map, as well as (separately) the individual
viewable faces (which is, I think, all that the engine actually needs
to draw things). So it might be possible to delete the brushes from the
.bsp without affecting the ability to play the map.

There are also other tricks that will break my decompiler right now -
such as the old HL1 trick of using an extra-long entity property
(greater than 256 characters), which will crash Hammer when you try to
load the decompiled .vmf.

the idea that you could put a particularly shaped brush in the level to
stop a decompile sounds good, but if you intend to use this, then i
suggest uploading a prefab of this shape as soon as possible, so that
people working on maps atm can include it.

Fishy, I was thinking more that the onus of mangled geometry would be
on the author of the decompiler (which, if you look at the quality of a
decompiled map, is already half way there :smile: )

I have a deep seated problem with restricting tools simply because they could be used to do something wrong, when in fact they have many legitimate purposes.

I do too. I didn't like how they shut down Napster. It is like banning guns because SOME ppl shoot other ppl. or banning ALL computers because they could POTENTIALLY control nuclear weapons. Granted, these are extreme, but it's the same principle. I want a decompiler that can change the authors name to mine. I may not do it, but it's my right to have such a program.

There are a few things that would concern me.

A mapper would have to guard his pre-release BSP with a lot more
care. What if you posted a beta map semi-privately on a forum,
and someone got a perfect VMF from it and released it as his own?
You really couldn't prove that it was yours to begin with.

On the flip side, there are quite a few legitimate uses for it.
I've already fired up my hex editor and looked at several maps to see
how they use entities, and the person I learned about the !activator
identifier from did this as well.

I suppose that it's your decision. If I were in your shoes, I
would probably release it just because it hasn't been done
before. However, there isn't really an example of something like
this happening in the history of the gaming industry. Like someone said before, there's no way to tell
what might become of this. It would probably force mappers to be
more protective with their beta maps (or craftily carve their names
into it somewhere), but there would be much to learn as well.

It's a very tough decision, I don't envy you.

I say it is a great idea for expereinced mappers or beginners trying to learn something. It could be a HUGE help to people.

There are setbacks like people trying to steal other people's maps, but the idea you had about putting something in it to be incapable of decompiling is a good idea and should work.

I say go for it, it will help a lot of people.

I think that in the right hands a decompiler will improve their
knowledge of mapping, and help them mapping. Mine are not the right
hands, as proven when the only thing I learned from the vmfs of the SP
levels is how you can make stars etc whizz past very fast, how to make
npcs look at certain points and how to add background music. I still
haven't figured out adding sentences because bastard valve uses
coreographed sequences, which are pre-programmed, and don't stand a
chance in hell of doing what you want them to. On the other hand, I
have just realised I could put all my sp maps for my pack (all two of
them) into one big one, thus eliminating serveral billion bugs due to
dodgy changelevel stuff.

I know! Make it so that the mapper can specify what parts of the map he wants decompilable! Then you can learn, but not rip off!

EDIT: On second thoughts, thats probably impossible

It's good to see that you have ethical concerns about all this, and I'm glad people are seriously considering the ramifications of what a perfect decompiler could do. I'm personally of the mind that a decompiler that works really well and recreates the maps would be an invaluable tool, especially for trying to figure out all of Valve's tricks.

However, as has been previously mentioned (and I've been saying for years), the HL community is full of hardcore idiots who see no problem with stealing others' work. The HL community really is too decentralized and too large for these people to be called out and ostrasized, so there is a very big risk with releasing such a program.

Although I can tell you that noone should be blaming you if and when somebody's map gets decompiled and rereleased. I wouldn't hold it against you if one of my maps was ripped :wink:

As wierd as it may seem, you should only release it to very experienced mappers... people like Leperous or Reno or CJ, that way you know it won't be mis-used but will be of some use to others who will write tutorials. Handing it to lesser trustworthy people will eventually leave it to flood around on the internet.

People* who rip maps should be beaten to death with claw hammers

Arse s*ts

Some people found out how to make their map not decompile when a decompiler is used on it.

They hex edited the bsp and added a single characters and it stopped the decompilers from working.

But then again If I ever found out I wouldn't tell anyone because then they could just hex edit it back. Hmm...

what are the odds, this will eventually be a fully functional decompiler?

people, you guys are taking this way to serious. stolen material, will always be exactly that .. stolen.

consider for one moment, how easy would it be for someone to steal a map for unreal?

answer as easy as loading it in unrealED. yet the habit of stealing is almost unheard of in the unreal community, or it has slipped by me un-noticed at least.

a decompiler whether fully functional, or as good as their predecessors, will make no serious impact on the "availability" of stealing another's works.

for one reason, only the less gifted would consider it. secondly it would be mediately obvious that the less gifted suddenly got better or more skilled.

i say this with feeling, if you can make a fully functional, and errorless decompiler, go for it. i know several mappers who lost their only copy of their own work, through no fault of their own but had no way to recover it, because they only had a .bsp from some friend.

a decompiler, would be a blessing, not a curse.

/ 2 cents.

Handing it to lesser trustworthy people will eventually leave it to flood around on the internet.

As if there isn't already a crap load of bad maps out there. Doesn't matter what happens to it, it'll get abused. So why bother preventing it?

StickFigs it was just compiling again with -onlyents, but sometimes onlyents made your map have invisible walls appear at random...

<DIV class=quote>
<DIV class=quotetitle>? quoting Myrk-</DIV>
<DIV class=quotetext>StickFigs it was just compiling again with -onlyents, but sometimes onlyents made your map have invisible walls appear at random... </DIV></DIV>
What?

I say go for it and realease this program. So what if some n00b makes some "changez" to your map- most of us don't make maps so that we get lots of money and ?ber-street-cred for doing so. And I think it's wrong to discover some kind of cool entity effect, and hide how it's done from other people- this is NOT our own game we're modifying, after all... If you've made something awesome, share it with others.

<DIV class=quote>
<DIV class=quotetitle>? quoting Nickelplate</DIV>
<DIV class=quotetext>It is like banning guns because SOME ppl shoot other ppl</DIV></DIV>

Taking someones life is slightly beyond copying someone else's map, but fair point Of course, if a lot of people are getting shot then banning guns is a good way to stop this from happening. If a lot of people start ripping off other people's maps, then perhaps "banning" this program (i.e. introducing something into BSPs that prevent the decompiling process) would be a good idea too, however this is not yet happening!

Even if you don't release it, someone else will release an alternative. Shivers. The decompiling mayhem of HL will move on to HL2. It can't be avoided :sad: .

What decompiling mayhem? Personally, I don't recall any particular
problems with people's maps getting ripped off - the HL1 decompiler was
extremely ineffective and so it was hard for that to be done.

I've no problem with anybody releasing a decompiler, and if you are the
first to do it then it will be a great thing to have in your portfolio
if you are interested in a coding career. I say go for it.

D00d 1 just was wndrng if u could give me the VmfZ 4 sum mapz i waNnA make some sick Changez too!!! No, I'm just kidding/bored. I agree with Yak that there will always be asshats who're gonna steal your work. There will always be hackers there will always be music and movie-downloaders. <---(some people I know not excluding myself.) I think that if you ever did make that decompiler, it would be a great tool to have. The only maps that will even be effected are the high-profile ones like de_dust and the contest winners. And no one will STEAL them, they will simply make changes and put "R0X0rz D00d ReMiX!" at the end of the map name. Sure, It'll piss me off, but it won't effect me as long as i never joine a server with these "remixes" playing.

Has any one here seen a decompile that is actually played on servers?

its
becaus edecompiles are ussually by ultimate noob mappers, and the
recompiles suck any way. SO release it, no recompiled map gets far.

Its not that big of a deal, but I have seen many maps like dust_2.5
etc. I personly dont like the fact that some kid was able to
mangle a map and negate the hours of work the real creator put into the
map. But that is just my opinion, I just hate seeing those maps
and thinking that some where some kid is looking at a list of servers
and goes 'w0w my maP is 0n 2 servers!!1!"

I say go for it and realease this program. So what if some n00b
makes some "changez" to your map- most of us don't make maps so that we
get lots of money and ?ber-street-cred for doing so. And I think it's
wrong to discover some kind of cool entity effect, and hide how it's
done from other people- this is NOT our own game we're modifying, after
all... If you've made something awesome, share it with others.

Again, its more that I have a problem with people takeing with out
asking. I dont have any problem with giving away source files or
anything like that. I love to see people learn from my
maps. I just think that if you really want to see how somthing
works, send an e-mail to the map maker.

Though, I agree with the gun example. If I were a noob mapper I
would want to be trusted with the power to look at others maps.
People will cheat and steal, but I guess the power to teach out wieghs
the negative.

oh, and Rof, you could add a vertex on the same plane as two others,
thus making a line of three. This will make the map
uncompilable. It is also very hard to find becuase (if I remeber
right) hammer wont find of fix the problem for you.

<DIV class=quote>
<DIV class=quotetitle>? quoting Rof</DIV>
<DIV class=quotetext>

In particular, the HL2 compile tools store every original brush and plane that was in the map
</DIV></DIV>

Didnt the HL1 compilers did this too? It's the nature of CSG to store the original brushes and remember all the undergone operations. Your suggestion of only keeping the faces would need a B-rep datastructure, which i dont think is implemented in the compilers.

anyway, about the issue of learing-with-decompiler vs stealing-with-decompiler. First of all i think the idea of only the established mappers having them isnt so usefull. Sure there'll be no stealing, but there'll be not much learning either, since the not-established mappers dont have it.

IMO all a decompiler should be able to do is provide "look-but-dont-touch". If someone really wants to remake your map, he has to rebuild it himself from scratch. If the author has no problem with others "remixing" his map, he should just state in the text file that the .vmf can be requested by email.

This way no security keys like prefab brushes should be inserted into the map.

In short: for me its ok if you release it, provided it's 100% look-but-dont-touch (e.g. like you said: shifting all the vertices randomly)
...and from your signature it looks like you released already

Didnt the HL1 compilers did this too? It's the nature of CSG to store
the original brushes and remember all the undergone operations. Your
suggestion of only keeping the faces would need a B-rep datastructure,
which i dont think is implemented in the compilers.

Hmm, I didn't know that. I'd gathered the opposite, but I haven't done
that much research on HL1 decompilers. I've mostly gleaned the map
structure from the odd article on the web and the SDK source files.

...and from your signature it looks like you released already

Maybe I wasn't clear, but yes, I've already released (about a week ago)
what is essentially a "look but don't touch" type decompiler. The
question I was asking was whether I should release the next version,
which produces much better brushwork.

DrGlass, good idea about adding a co-planar plane. I'll have to test it, but that might be perfect.

When compiling I believe the coplanar face error gives the exact brush
in question so it would be trivial to fix anyways (at least thats how
HL did it, haven't created that error yet in HL2)

Nearly all the newer game engines don't use precompiled maps but
instead distribute maps in source form. It would be impossible to
stop someone from doing maliscious things with the source, because it
is necessary to be distributed that way if you want to play it.
while this argument may not justify a decompiler on this specific
engine, it illustrates the risk you take in releasing a map in the
first place. There will always be people out there who can steal
your work, whether its a map, music, etc. Yet the world goes
on. Don't let the possibility that someone does something wrong
with your work stop you.

The power to teach is the greatest power of all. I personally
would love to use it to see how "they" did something, or to see how to
set up a certain entity, etc.

The amount of work involved in removing a co-planer face from every
brush in the level would be a huge task, I dont think there would be an
easy way to do it. You would have to find everysolid entity and
delete the extra vertices.

Then on the same side, if you wanted to copy a small section of map to test and use the problem could be fixed.

I have changed my mind on the whole thing, if you can get the look but
dont touch to work thats great. But at the very least have a pop
up box everytime you decompile with a short message like "please use
this as a learning resource, if you want to copy or use any thing in
this map contact the owner and ask. Honesty is super cool"

Also, you may want to send an e-mail to valve and see how they feel about the whole thing.

<DIV class=quote>
<DIV class=quotetitle>? quoting ReNo</DIV>
<DIV class=quotetext>What decompiling mayhem?
</DIV></DIV>
wishpers The old Prefabland had about 2000 decompiled fabs. I shamefuly admit that in my n00b years i posted some decompiles myself.

There have always been decompilers around. Only the good maps will
survive. Even ?f some noob decompiles a great map and punches holes in
the walls, it will still look like sh**.

Release it. :smile:

Go ahead and release it. Don't bother with all the misuses it can be
put to. (Dihydrogen Monoxide can
cause death by drowning)

<DIV class=quote>
<DIV class=quotetitle>? quoting fraggard</DIV>
<DIV class=quotetext>Go ahead and release it. Don't bother with all the misuses it can be put to. (Dihydrogen Monoxide can cause death by drowning)
</DIV></DIV>

yeah, what he said..

acts like i know what he said
if we all worried about abused inventions, they never would have released "food"

if we all worried about abused inventions, they never would have released "food"

they invented food? intresting. :wink:

I dont think the argument should be wether or not to relese it, but how
to curb people from over eating... errr... doing bad things with the
tool.

is my humor that vague?

i sit here rolling over things like that, and the reception i get online is usually either disinterest, or outright ignored.

i suppose, i should have my funny bone looked at since it seems to be broken, or locked in the "on" position :heee:

If you don't release it chances are there will only be one other decompiler released.

I've only ever found 2 for HL1 and they work completely differently.

I wonder how many people posting here are actually just making up excuses to release it because they can't wait to steal some prefabs or take an entity setup that someone took days to make and stick it in their own s**thole map.

And to whoever posted this thread, quit acting like you care what people think, you're going to release it anyways and you know it. The most you could have hoped to achieve with this thread is having people ready to go steal someone's hard work kiss your ass.

I wonder how many people posting here are actually just making up
excuses to release it because they can't wait to steal some prefabs or
take an entity setup that someone took days to make and stick it in
their own s**thole map.

Keep wondering. It'll do you good.

Edit: Quoted you... I get the feeling you might "change" your views. You fit the profile.

<DIV class=quote>
<DIV class=quotetitle>? quoting fraggard</DIV>
<DIV class=quotetext>

<DIV class=quote>
<DIV class=quotetitle>? quote:</DIV>
<DIV class=quotetext>I wonder how many people posting here are actually just making up excuses to release it because they can't wait to steal some prefabs or take an entity setup that someone took days to make and stick it in their own s**thole map.</DIV></DIV>

Keep wondering. It'll do you good.

Edit: Quoted you... I get the feeling you might "change" your views. You fit the profile.
</DIV></DIV>
Is that a threat? Because I really don't care.