Ultimate Doom demos [-complevel 3]

JCD said:

E1M3S UV speed in Coop 3P in 0:12

Woot! 3-player co-op :P Fun stuff, cool stuff.

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I sacrified myself to open the secret exit's door. :D . This is a brave act , isn't it?

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Been semi-retired from Doom lately, but this seemed worth unretiring for.

E2M8 pacifist in 12:42.

Also Tyson WR.

p2m81242.zip

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Unbelievable, this should be on CNN. :D

Will there be an explanation of how it works exactly?

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Memfis said:

Will there be an explanation of how it works exactly?


I will try my best to explain the strats and how I came to them, but my knowledge isn't perfect and largely based on empirical evidence that I gathered from testing with a modified e2m8, no code knowledge.

My initial thoughts on this run months ago was the TAS challenge 1 strat, which seemed almost viable because lost souls aren't too likely to trigger a cyber to wake up fully, but it's still a ton of attacks needed and the luck required for there to be no wakeup at all is too high for non-TAS. Aside from that, cybers have an odd behavior where sometimes after being attacked by a lost soul in asleep state, they will walk a short distance or change directions for whatever reason, then go back to sleep. I suspect it may have something to do with how lost souls go to sleep every time they attack something and end up facing away from the player if the player fired no shows prior. These direction changes could result in that strat suddenly failing because the cyber faced the player even if he wasn't woken up to attack the lost soul.

Afterwards, my thoughts went to getting the cyber stuck being the only option, and eventually, I figured the narrow entrances into the central switch room were the best option, naturally because if a cyber is stuck there I can keep a lost soul on the other side and be safe from it. Recently, from the existing demos of cybers getting stuck (Europa, ev30, etc.), I noticed an important prerequisite for it, and that's that the cyber needs to have nowhere to go in front of it. It doesn't appear to be possible otherwise as the cyber will just go forward if you attempt to prevent it from moving. So, I tested with a test map of the cyber starting in the spot I used in the pacifist, and it worked.

The other problem is getting the cyber into a proper state before getting it stuck. If, as in my test map, it is fully asleep at the beginning of the level and near a wall, you can get it stuck by just running into it every time. If it's shooting, you're out of luck because it will get stuck in the shooting state. If it was shooting, killed its target, and fell asleep it still appeared to be stuck in the shooting state if you attempt to stuck it while it's asleep. Then, there are a number of oddities that I'm not fully sure of exact explanations for when the cyber is not shooting. For instance, when he was infighting a soul he could see and I attempted to get him stuck, he would sometimes look like he got stuck but then in that state start firing to kill the lost soul it can still see and then switch to me. Also, if you try rerecording from this demo and punch him immediately or 1-2 seconds after it gets stuck, it will fire at you, even though it is stuck (but if you wait long enough, this won't happen). I'm not sure whether the last two things are related to the same underlying logic or similar logic, but they made it more complex to get the cyber stuck than it would seem.

Initially, I was trying something far more luck-based by pulling in lost souls from the side opposite the one with the cyber and getting them to infight with the cyber after killing all the lost souls on the cyber side, until I got lucky and had a demo where a lost soul infighting with the cyber was pushed into the switch room by blast damage from the cyber. I wasn't prepared for it so I lost the opportunity quickly, but that made me realize that grinding for that luck in the beginning makes the ending practically consistent. Furthermore, being able to abuse the lost soul logic of getting stuck in walls allowed me to get the lost soul into a position where the still infighting cyber could not see it from the entrance, meaning as long as all the lost souls on the cyber side were dead/lured away, I was safe to try and get the cyber stuck as long as I needed to.

BTW, for anyone looking for a really easy (if frustratingly luck-based) demo to do: from rerecording, Tyson time here ended at only five minutes, and you could probably to improve that through increased aggression by being less concerned with luring all the lost souls away since you can shoot/fire (maybe could approach the GM Tyson time?).

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Incredible, I've literally been waiting like 15 years to see if anyone could pull this off. This deserves a news submission on the front page.

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Here's a brief overview from the steps as I understand them from watching the demo.

There are two things about the Doom engine you need to know:

  1. When you fire a weapon in Doom, the sound activation trigger flood-fills all the sectors it can reach - and that flood-filled sound activation stays there permanently. It's less like making a sound monsters can hear and more like changing all reachable sectors to a "monster activate" state.
  2. When Lost Souls do their charge attack, their natural inclination is to go back to "sleep" when they hit something. Only if they are in a flood-filled "monster activate" sector will they always wake back up.
So knowing this, the steps for a E2M8 Pacifist are:
  1. Open a door and activate the Cyberdemon and lure the Cyberdemon into one of the rooms
  2. Get a Lost Soul to hit the Cyberdemon with a charge and then get lured towards you in the center room before the Cyberdemon has a chance to retaliate
  3. In the center room, get the Lost Soul to charge into a wall so that you are behind it, so it goes to sleep and you can exit without the Lost Soul seeing you
  4. Exit on the far side from the Cyberdemon, and run around luring all the Lost Souls into a position where they won't be able to reach you later
  5. Go back into the center room, and get the sleeping Lost Soul into a position where a) it's sleeping again, and b) the Cyberdemon won't be able to see it through the open door
  6. Open the door to where the Cyberdemon is. The Cyberdemon is still pissed off at the Lost Soul so it will continue trying to walk into the center room, but it can't actually hit it. Press up against the Cyberdemon until it gets "stuck" in the corner towards the center room and can't move in any direction.
  7. Only now do you actually punch the air, flood-filling the map with the "monster activate" trigger. The Lost Soul in the center room will wake up and start trying to attack you, but the Cyberdemon is in the way, and because of the level layout, it can't ever actually get around the Cyberdemon to attack you directly.
  8. Wait a long time.
  9. Success!

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Linguica said:

Here's a brief overview from the steps as I understand them from watching the demo.


Yeah, that sums it up pretty well. Steps three and five can be merged if you get the lost soul into the step five position the first time around, but I was low on health and decided I would do that later on.

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This is absolutely, unequivocally, undeniably genius.

Absolutely phenomenal work!

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20 years on and I still see shit in this game that frankly amazes me.

Hail to you and your irrepressible ingenuity, 4shock.

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episode 3 uv-speed in 3:41 (4:20 with m8), 3 (9) second improvement over the previous record by Hi Jango.

 

really good run as I was only looking for a 1 second improvement, also recorded in crispy doom v3.2

 

Youtube:

 

ep3-0341.zip

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