Mysterious Flood animation

Posted February 3rd 2018

Associated movies… BCM268

He doesn't seem happy

When playing around with a friendly yeti Flood on top of the map - namely swamp guy, having saved him from scripted death and got a checkpoint up close - something unexpected happened. After dropping him (he happened to be droppable), I shot him promptly after reanimation and he waved his arms - an animation I'd never seen before. It seemed like maybe I'd discovered a new animation, thanks to the very unusual situation of being face to face with a friendly Flood. The arm waving suggested either anger or shock, but it was hard to be sure which.

I subsequently investigated, and made BCM268. And now here's my article about it (mostly drawing on information already mentioned in the movie's written commentary).

I expect you can equally get the animation from any other friendly yeti Flood you manage to save, but I haven't yet confirmed that. Nor do I know if it's possible to get the animation from a non-friendly Flood. For the time being then, let's focus on my situation with cliff guy.

Hit as he turns

Attacking after reanimation

The main way to get the animation is to attack after he rises off the ground. But it needs to be at just the right time, and from 'behind' relative to the direction he's facing as he rises. In this context, 'behind' means anywhere in his rear 180 I think - which I tested by standing at various angles around him when shooting.

The window of opportunity is small, and also seems variable from one checkpointed situation to another. From video analysis, it seems that he has to be hit during his turning animation (he turns after rising), or on the frame right after that. But that's the largest window of opportunity. In other checkpointed situations the window can be smaller, lasting for fewer frames after he starts turning. In one situation mentioned in my written commentary for BCM268, the window comprised only the first two frames of his turn. In another it comprised the first six.

Even if your attack is in the appropriate window of opportunity though, there's randomness in whether you get the animation, and the odds are low. It looks like the chance of success is under 5% - so it can take a lot of retrying to succeed. I was averaging about 2.6 minutes work per success, in a test I did.

Success with a ground blast

In regard to the attack, a pistol or shotgun shot is easiest, and it doesn't seem to matter where you hit. But melee works too. It's just a bit harder to time, because there's more of a delay between your button press and his being hit. Grenade blasts work too (including tagging), but are hard to time, especially since there's some randomness in how long he remains unconscious. It can be anything from about 3 to 4 seconds.

You don't need to be close to cause the animation. You can get it with a shot from a long way off.

Amusingly, you can get the animation even if he has no arms. His torso movement is still evident and identifiable.

He can do the animation without a head, but seemingly not if his head was already gone before rising. That exception seems rather strange, but I tested it extensively.

Can he do the animation before teleporting? I tried to get it but never did, so I suspect the answer is no. That may be due to his scripting dominating (taking precedence). I was also unable to get the animation after flipping him to enemy status. I suspect he needs to be friendly.

Checkpoint, while he's down

Getting a primed set-up

If you get a delayed checkpoint just after dropping him (see pic), you may find that he's primed for arm waving. By 'primed' I mean that the randomness is gone. The game has already settled on whether or not he can do the animation; so as long as you get your attack timing right, you'll get the animation. This enables you to see it repeatedly and easily.

I showed the creation of a primed set-up in BCM268 around 4:16, and there's another such set-up featured later, in which I had a bigger window of opportunity for the attack. I delayed a checkpoint associated with the lift settling at the top. Getting a primed set-up can take many tries though, as you only have a slim chance of success each time. Still, once you've put in the effort, it's nice to be able to get the animation easily.

Different initiation

As it turns out, attacking after reanimation isn't the only way to get the arm waving animation. When doing takes for my comedy suicide ending to BCM268, there was one take involving a tag plus needle bangs, in which I saw him doing the animation as I flew off. And specifically, it looked like a needle bang was responsible, and that it went off on his back.

Success with melee

What does it represent?

What does the animation represent? Bearing in mind how the attack seems to need to come from behind, one obvious idea is that it represents shock. Unlike when you shock a covie though, you can't do it with a wide shot fired from close up; and nor do you need to be close at all. So if it's indeed just a reaction of shock, the mechanism is quite different than that for covies. That would be odd, and arguably weighs against the idea.

When I posted my movie, I was leaning towards the idea that it represents anger in reaction to friendly fire/attack. The arm waving certainly looks more like expressing anger than surprise to me, being a prolonged waving of the arms rather than a brief involuntary response. However, why would the attack need to come from behind? That wouldn't really make sense, if the reaction is simply meant as a protest.

Shortly after posting the movie, a friend was able to provide sound files extracted from the game, and I found the one for the sound of the Flood's arms raising. It's named 'stand_pistol_surprise_front', which obviously supports the theory that the animation represents surprise/shock. Incidentally, in regard to the term 'pistol' in the file name, I think that's just a code word relating to the armed status of the subject. It indicates something like "armed with typical weapon or none at all". The point being, his armed status causes no additional sound in regard to movement (unlike say, the case of a Grunt with a fuel rod gun).

In view of all this, I'll go with the 'shock' theory for now, even though the arm waving still looks more like expressing anger to me. If correct, I think this reaction of shock may be latent in all Elite combat Flood, but normally never triggered because aggression related behaviour dominates (that could be a design oversight, or maybe Bungie knew but weren't fussed to address it). As such, you might only be able to see it from a friendly Flood.