Lightning bug fun

Edit history:

dex: 2007-04-08 02:50:39 am

2007-04-08 02:46:13 am

Invisible avatar

Hello dudes (and dudettes, obviously :P). As some of you may know, I have pursued the e4m8 eh improvements for quite a lot of time. One of the 'breakthrough' tricks was meant to be killing a shambler through a wall, saving no less than 4 seconds. However, I couldn't find a way to zap him through that wall and gave up. That's when Lag.Com came back from his long absence, and agreed to check a few things up for me (as he is a lot, lot better coder than me). After a few days he understood the mechanics of the bug, and made a modified .dat file to help in his research even further. I'm sure he'll tell the technical details to you.

Anyway, I haven't yet found the way to kill the shambler through the wall. But...from my research quite a few interesting things spawned. And from that, after figuring the way this problem works a little, spawned this demo:

http://download.yousendit.com/5877B7BC72307F90

It's a 100% kill cheated through e4m8 on easy difficulty (didn't take one secret, I wasn't arsed enough for that). It took just under 7 minutes. You may ask "what's so special about it dex?". Well, the level has 46 enemies. 40 of them are killed without being aimed at during the demo, using only the thunderbolt. And two from those get killed the normal way because, well, they jump into my line of fire instead of being where I want them. The demo was recorded on first try, so don't expect any killer speed Tongue

This of course could shake up the whole 100% scene, most of the 100%s on maps that have shaft on them will become obsolete. And from this spawns another question: is it allowed? Is it not? Or maybe it should be made another category? I'd say only the SDA staffers will be able to answer that one....well, enjoy. And special thanks to Lag.Com Tongue

Thread title:

Hello dudes (and dudettes, obviously :P). As some of you may know, I have pursued the e4m8 eh improvements for quite a lot of time. One of the 'breakthrough' tricks was meant to be killing a shambler through a wall, saving no less than 4 seconds. However, I couldn't find a way to zap him through that wall and gave up. That's when Lag.Com came back from his long absence, and agreed to check a few things up for me (as he is a lot, lot better coder than me). After a few days he understood the mechanics of the bug, and made a modified .dat file to help in his research even further. I'm sure he'll tell the technical details to you.

Anyway, I haven't yet found the way to kill the shambler through the wall. But...from my research quite a few interesting things spawned. And from that, after figuring the way this problem works a little, spawned this demo:

http://download.yousendit.com/5877B7BC72307F90

It's a 100% kill cheated through e4m8 on easy difficulty (didn't take one secret, I wasn't arsed enough for that). It took just under 7 minutes. You may ask "what's so special about it dex?". Well, the level has 46 enemies. [b]40[/b] of them are killed [b]without being aimed at during the demo, using only the thunderbolt[/b]. And two from those get killed the normal way because, well, they jump into my line of fire instead of being where I want them. The demo was recorded on first try, so don't expect any killer speed :P

This of course could shake up the whole 100% scene, most of the 100%s on maps that have shaft on them will become obsolete. And from this spawns another question: is it allowed? Is it not? Or maybe it should be made another category? I'd say only the SDA staffers will be able to answer that one....well, enjoy. And special thanks to Lag.Com :P

Lag.Com

2007-04-08 02:56:42 am

sda loyalist

Yeah, it's pretty crazy. Smiley

I recorded a short clip of killing some unseen grunts in e1m1, but it's gone walkies.

If you're wanting any technical info about the trick, ask me. I would rather send in a demo which uses it first though, just to be mysterious and all.

laughing_gas

Edit history:

laughing_gas: 2007-04-08 03:13:12 am

2007-04-08 03:12:53 am

Existence as you know it is over

Seems like it would belong in a separate category. Pretty cool glitch, though.

Mandel

2007-04-08 05:44:55 am

Mumma

without having watched the video:

why a separate category? the trick has always been possible, hasn't it? and already used, on end for example.

which id maps have shaft anyway?

Aquashark

2007-04-08 10:06:21 am

omg! wtf?

wow! just what we need.. a new motivation for new improvements & projects Smiley

it's really astonoshing how useful bugs still pop out of a 10+ year old game..

Lag.Com

Edit history:

Lag.Com: 2007-04-08 10:10:27 am

2007-04-08 10:08:48 am

sda loyalist

The separate category idea is purely because the glitch is so ridiculously vast. You could literally kill every monster in the map by standing in one room and spinning round at certain angles, firing the thunderbolt. Well, on some maps.

At end... yes, it's used there, but at the time it wasn't understood. I remember Stubby told me something like "the beam goes through the wall at really odd angles, I extended the line and they don't hit any enemies" etc. Now we know why, and it has enormous possible application.

I'm sort of sorry for figuring it out. :/

Edit: Note the long firing sequence in the side area where the pentagram is. dex managed to kill the two zombies hiding behind a wall at the 'holes in the floor' area. Do you see the range on this glitch yet? Smiley

Stubgaard

Edit history:

Stubgaard: 2007-04-08 12:31:07 pm

2007-04-08 10:20:28 am

Hey Ho Let's Go

Quote:

wow! just what we need.. a new motivation for new improvements & projects Smiley

it's really astonoshing how useful bugs still pop out of a 10+ year old game..

There's absolutely nothing new in that e4m8 demo I haven't seen before. I've seen it all happen while first practising for the End demos years ago, and there's been several trick demos showing off this bug as well (also some on e4m8.), and even some demos on SDA which are using the bug un-intentionally. The difference is that we now understand the physics behind the glitch thanks to Lagdotcom's "investigation".

Stubgaard

2007-04-08 10:23:04 am

Hey Ho Let's Go

Quote:

Edit: Note the long firing sequence in the side area where the pentagram is. dex managed to kill the two zombies hiding behind a wall at the 'holes in the floor' area. Do you see the range on this glitch yet? Smiley

That has been known for years. It's just that no-one has used it in a demo yet. The same goes for hitting the fiends in the silver key room, we've known about that ever since I first discovered the bug, but no-one has managed to use it yet.

Stubgaard

2007-04-08 10:25:00 am

Hey Ho Let's Go

I'm eager to see what the re-newed understanding of this glitch can result in though Smiley

Aquashark

2007-04-08 11:10:30 am

omg! wtf?

does this bug affect shootable buttons as well?
might be useful in runs too Smiley

Lag.Com

2007-04-08 12:35:45 pm

sda loyalist

Yeah, it's possible.

dex

2007-04-08 01:51:56 pm

Invisible avatar

First thing's first: there is a possibility to kill at least a few other monsters from the room with penta. The angles for that are so incredibly precise I had to try for 10 minutes to get just one enemy.

Next, from my understanding it seems the "range" of the lightning bug is either infinite or very, very big. However, on distances bigger than 600 units, minimal changes of angle and position move the beam by at least 100 units, and it's getting harder and harder with distance. The zombies I kill from the pentagram room are about 1300-1400 units away, which is a pretty big range. As you could also see, while I don't precisely understand how EXACTLY this thing is counted, I have rough estimates where to aim to kill the enemy. In some enemy cases I can kill them with one precise shot, when I *Know* where to aim. The armor room with 4 zombies (the one after the thunderbolt pickup) is a good example of that, I know exactly how to shoot. This is a case with at least a few enemies in the level. The rest were "calculated" during demo. I thought I could kill at most 20 enemies like that, you can imagine my surprise when I managed 40. And lastly, I'm currently trying to find a way to zap that shambler through the wall. With the rough understanding I have I may accomplish this. And if I do, e4m8 eh time will go down by at least 5 seconds. Which only goes to show this new trick's potential.

First thing's first: there is a possibility to kill at least a few other monsters from the room with penta. The angles for that are so incredibly precise I had to try for 10 minutes to get just one enemy.

Next, from my understanding it seems the "range" of the lightning bug is either infinite or very, very big. However, on distances bigger than 600 units, minimal changes of angle and position move the beam by at least 100 units, and it's getting harder and harder with distance. The zombies I kill from the pentagram room are about 1300-1400 units away, which is a pretty big range. As you could also see, while I don't precisely understand how EXACTLY this thing is counted, I have rough estimates where to aim to kill the enemy. In some enemy cases I can kill them with one precise shot, when I *Know* where to aim. The armor room with 4 zombies (the one after the thunderbolt pickup) is a good example of that, I know exactly how to shoot. This is a case with at least a few enemies in the level. The rest were "calculated" during demo. I thought I could kill at most 20 enemies like that, you can imagine my surprise when I managed 40. And lastly, I'm currently trying to find a way to zap that shambler through the wall. With the rough understanding I have I may accomplish this. And if I do, e4m8 eh time will go down by at least 5 seconds. Which only goes to show this new trick's potential.

GinKo_

2007-04-08 03:44:56 pm

Very interesting demo indeed Cheesy

Gives a new look at the possibilities for it.

As Stubby, said it's not a new trick being discovered but an old one being understood. I remember there was an acro 100% that used it in intermission, there's probably some more examples.

Well, it will certainly lead to some improvements, but I can't see why to make a new category for it, people are just too scared of new stuff. It's not like pressing a single button and WHAM! genocide. It requires skill and it would only make demos more interesting imho.

Also, would you mind sharing your findings? (the tech talk) I was always curious as to how it worked, although I'm not that good of a 100% player to make much use of it. Great job btw Smiley

there's no need to be sorry at all.

dex

2007-04-08 04:06:09 pm

Invisible avatar

GinKo: Like I said, the trick is not *fully* understood yet. We have found a rough pattern, but there are anomalies to it and we are trying to work out why do they appear. Also, I would want to send a demo using that trick first as well. Don't you worry though, when I finish my e4m8 eh in a better time, me and Lag will explain the trick in detail (hopefully we'll find out why the anomalies appear). Generally, this happens because of a bug in the code. The shaft was meant to be a very thick beam consisting of three lesser beams. For that, vectors were generated and then were supposed to be normalized. However, the code of normalization has a bug, it has an instruction to normalize, but...never assigns it to a variable :). The result are two additional beams. Most of the time they are completely out of the map bounds, there are angles where it ends in the map though, and then there are anomalies.

The Quake designers must have noticed the shaft doesn't deal the damage the way it was intended, and to keep the weapon balance they tripled the damage from one beam. However, they did not delete the additional two beams.

This also brings another trick - it should be theoretically possible to deal tripled damage from shaft, if you make all the beams go on one line (the angle for that is very precise, but possible to get). And that could really speed up some 100%s, after all tripled damage is a lot when killing a shambler. And with Quad, that means 12 times the normal damage.

GinKo: Like I said, the trick is not *fully* understood yet. We have found a rough pattern, but there are anomalies to it and we are trying to work out why do they appear. Also, I would want to send a demo using that trick first as well. Don't you worry though, when I finish my e4m8 eh in a better time, me and Lag will explain the trick in detail (hopefully we'll find out why the anomalies appear). Generally, this happens because of a bug in the code. The shaft was meant to be a very thick beam consisting of three lesser beams. For that, vectors were generated and then were supposed to be normalized. However, the code of normalization has a bug, it has an instruction to normalize, but...never assigns it to a variable :). The result are two additional beams. Most of the time they are completely out of the map bounds, there are angles where it ends in the map though, and then there are anomalies.

The Quake designers must have noticed the shaft doesn't deal the damage the way it was intended, and to keep the weapon balance they tripled the damage from one beam. However, they did not delete the additional two beams.

This also brings another trick - it should be theoretically possible to deal tripled damage from shaft, if you make all the beams go on one line (the angle for that is very precise, but possible to get). And that could really speed up some 100%s, after all tripled damage is a lot when killing a shambler. And with Quad, that means 12 times the normal damage.

Ankh

2007-04-08 05:35:03 pm

Maybe there is a way to make the two additional beams visible. I guess this would need an engine modification.

dex

Edit history:

dex: 2007-04-08 05:45:46 pm

2007-04-08 05:45:17 pm

Invisible avatar

We already have a progs.dat that does this Tongue

But even with it, the trick seems random at many places...but it helped finding the rough pattern.

Droog_Andrey

Edit history:

Droog_Andrey: 2007-04-08 10:01:27 pm

2007-04-08 09:57:09 pm

Thunderbolt Forever :)

As for e4m8 and e4m7(!) ... Smiley

http://speeddemosarchive.com/yabb/YaBB.pl?board=run_discussion;action=display;num=1112800441

http://speeddemosarchive.com/yabb/YaBB.pl?board=improvements;action=display;num=1099139938

Stubgaard

2007-04-08 11:20:01 pm

Hey Ho Let's Go

The Cheated Nightmare 100% on e4m3 is good LG-bug fun too. You can trigger the 30 second fiend sequence by shooting up in the ceiling. As you can see from the tables, the first demo that uses this particular glitch dates all the way back to summer 2001, this was before I figured out how to use the trick with success on End. This was the very first demo that made use of the glitch, and the End demos I recorded back in the summer of 2002 were the next ones to follow (apart from a few trick demos).

http://speeddemosarchive.com/quake/otherdemos/demos.php?level=e4m3

Arturo Garcia

2007-04-10 01:57:15 pm

I can see why a few people would think that a new category would be good... this trick would make the previous 10 years of playing on some maps, totally worthless. That's not fun Sad

And unfair to those who spent endless hours trying to perfect a demo, only to lose the record because of some dumb bug.

I've always wondered if I am the only one who absolutely HATES the intermission-killing bug? Yes, I've used it a couple of times myself... but I don't like it, it's not "pure", so to speak, to beat someone else's record with that trick. But it's not against the rules either, so what can we do? Nothing but sit back and enjoy the demos... Smiley

Lag.Com

2007-04-10 02:05:09 pm

sda loyalist

Tell that to Bergie. (tr1 eh) Smiley

lodis_

2007-04-10 02:48:11 pm

I would argue that that particular situation is different lag.com.

As I understand arturo he doesn't think firing nails or shaft in intermission is fair since you have exited and can still inflict damage on enemies. My tr1 eh uses a platform to kill enemies, I'm not interacting after exiting.

Arturo Garcia

2007-04-11 01:39:47 pm

Just to be a bit more clear: I just think it's unfair on maps that have been around for years, because it makes all the previous efforts useless if you can save time like that, since at the point, the previous guys weren't aware of this "bug".

And I don't like the fact that it can even be scripted... see the e2m3 EH record for example, that was too easy, to get that hellknight like that.. it requires more skill to quickly place the quaded grenades through that little window from the bridge, like it was being done before. No disrispect to Timo or anything, that demo and most of his others are awesome.

mwh

Edit history:

mwh: 2007-04-11 06:26:25 pm

2007-04-11 06:25:44 pm

In a sense it's always a shame when some super cool trick is obsoleted by another -- I'm sure we've all found cool slope jumps that turn out to be totally useless because they just aren't on the run route for a map. But this is the SPEED demos archive, so what's faster wins.

The lightning bug trick is going to be exceedingly annoying to exploit fully because of the precision it requires. Looking forward to the demos though!

(If you know anything about graphics programming and want to understand the bug, just read LightningDamage in weapons.qc. And cry, when you realize how far apart intention and effect are in this function)

Scott

2007-09-21 01:13:28 pm

I seem to recall a more indepth analysis of the lightning bug; I believe it was hosted on this site. The anlaysis included diagrams of what the multiple lighting shafts were doing and it included a mod you could install to see these multiple shafts. Essentially there are 2 extra invisible shafts that appear to be parrallel to the one that is visible, and these extra shafts are the source of this bug. Does anyone know where this page is that has this description and mod?

Lag.Com

2007-09-21 05:31:48 pm

sda loyalist

Yes, mwh made it once I told him what was going on. I'm not on my computer atm, so I don't know the link. I still have the pictures sat in My Documents though, haha.