Hitscan vs. "Projectile Bullets"

[.ex.inferis.]

Not exactly sure where this should go...? Thought of Editing but since this is more of a discussion request than an actual editing question, figured this would be a better place to post this in

I've read in these forums that projectile bullets can add a bit of realism. Coming from someone who's never actually fired a gun in his life (one day I shall), how is this so? And gameplay wise, how is it any different from hitscan, aside from the instant "point A-to-point B" mechanic of the hitscan? I ask one for the sake of arguement, and to see what the difference of opinions/aesthetics would be.

[Gez]

I think that given how most combat in Doom typically tends to be of the close quarters variety, hitscans are just as well.

Projectiles might also be blocked by certain linedefs which let hitscan pass. There's a prominent example in Epic 2, right at the start of (IIRC) MAP16. You're prisoner of a forcefield and must shoot a switch to turn it off. Don't try to shoot it with a rocket launcher. If you play it with ww-nazis, you'll have to cheat at this point because there isn't any ranged hitscan weapon in that mod.

[rollingcrow]

Projectile bullets are more versatile for making bullet weapons as they let you define a "range" for weapons because along with spread, you can adjust bullet speed and add bullet drop (negative ThrustThingZ). Hitscans are more limited as all you can do to limit weapon range is increase spread or literally limit how far a hitscan can go, however they can hit the aforementioned Epic 2 switch and other switches better than projectiles.

[Ed the Bat]

My biggest issue with projectile bullets is that they get blocked by non-shootable obstacles, whereas hitscans pass through. This has been an especially defeating shortcoming in attempting to design 'penetrating' bullets.

[TerminusEst13]

I've read in these forums that projectile bullets can add a bit of realism. Coming from someone who's never actually fired a gun in his life (one day I shall), how is this so? And gameplay wise, how is it any different from hitscan, aside from the instant "point A-to-point B" mechanic of the hitscan? I ask one for the sake of arguement, and to see what the difference of opinions/aesthetics would be.

It's a bit of a mixed bag.

In real life, bullets are indeed a projectile weapon--the bullet isn't instantaneous no matter how much gunpowder you put in the back. It has to be manually projected by force and flung out to the target, so there's always a period of time between pulling the trigger and the bullet actually hitting the target.
The thing is, it's simply too fast for the human eye to really keep track of. Even some of the slowest shotgun slugs have a travelling velocity of 335 meters per second, a little over a third of the speed of sound. Most game engines can't really handle speeds like that, though, nor would it really be worth it--so it's generally easier to make the bullet an instantaneous hitscan.
While projectiles are indeed "more realistic", they're only realistic to a point because if you make the projectile fast enough to accurately replicate a real bullet you might as well make it a hitscan.

But then we get into tracer bullets.
What are tracer bullets, you ask? Tracer bullets are bullets filled with little fireworks (actually a lot more complicated than that, but let's just say that for the sake of simplicity) mixed in with the gunpowder charge, which ignites when the bullet is fired and leaves a little "trace" behind them as they fire. They're slightly slower than actual bullets and have less mass, but make up for it by looking really fucking cool and getting to pretend you're a sci-fi hero firing a massive melty laser gun.



Seriously, look at that shit. On a scale of 1 to 10 in the range of coolness, it rates somewhere around a Dwayne Johnson.

A lot of modern games (and a lot of Doom mods, too) have incorporated this, and for good reason--it looks flashier, it helps the player to note where the bullets are going and/or coming from, and it allows them to slow down the bullets so they can see it coming for a split second.
If you want to come from a realism standpoint, however, it's even less realistic. The extra fire can tear up the barrel like nothing else, not to mention it gives away your position--and why would you want to make your bullet slower and less accurate? You want to hit your target.
It does have its uses, generally for marking a target for coordinated firing or loading the last few bullets in your magazine with tracers so you know when you're almost out, for heated firefights tracers are basically a non-option.

BUT FUCK REALISM.

When it comes to gameplay, Projectiles are generally a preferable choice for Doom and Doom-esque games, primarily due to the method of gameplay.
As this guy once elaborated on a long time ago, the biggest thing in Doom's favor of gameplay is the idea of maneuverability and speed as defense. You're really quite squishy by yourself, but swinging left and right allows you to dodge pretty much everything that comes your way. Except for hitscans. There's a reason that the zombies are so weak, and that's to upset the sheer power their hitscans contain--a room full of lowly Troopers can be one of the roughest encounters available, primarily because of the fact that their weapons are entirely hitscan.
See, in traditional Doom gameplay, you are theoretically capable of going through any encounter without ever taking damage. Every damage method available from every enemy has a prospective counter--outrun the Revenant fireballs, strafe past the Barons, hide behind a wall for the Archvile, etc. Hitscan...doesn't have a counter, with the obvious exception of "kill the dude first", which is where the weakness of the zombies come in. You can't outrun the bullet, you can't strafe past the bullet, you can't see the bullet coming and hide from it. Hitscan is entirely a lucky roll of the die; you get hit or you don't, and there's nothing you can do about it.

This isn't fun.

The difference between a game being difficult and a game being cheap is whether the player feels like it's their own fault that they died or whether it's the game's fault they died. In the end, the player should die only because they messed up, not because the game sprang up something unavoidable on them. Hitscans run completely against this, deciding whether you get hit entirely based on random chance, rather than because you slipped up a dodge or forgot about an errant rocket or ran into a room with no cover.
So, as unrealistic as it is, projectiles are generally a better choice for gameplay.

---

In my opinion, of course.

[Gez]

Doom isn't entirely about avoidable damage, though. See all these maps with mandatory traipsing in damaging floors, and the "super hellslime" damage type randomly "leaking" through the radsuit if the mapper had the courtesy of giving you one. That's why you get up to 200% health and there are medikits everywhere.

But to go back on the notion of hitscans vs. projectiles: the player has only three projectile weapons, but has seven hitscan weapons. (The BFG counts as both hitscan and projectile. Most of the damage comes from the hitscan tracers.) Enemies, though... There's only five hitscan enemies (one of which is an Easter egg, and another a boss everybody finds underwhelming), the rest are projectile or melee only. (Note that player melee attacks are hitscan; monster melee attacks aren't. They're just a distance check, with no actual scanning for hit.) Furthermore, except for the spider mastermind, all hitscan enemies are both quickly dispatched in a single shotgun shot (only the chaingunner has a good chance of surviving a shotgun blast to the face) and a convenient source of ammo for the player, which is also a source of mitigation for the annoyance they can be.

Finally, hitscan enemies will hit other enemies that stand in between them and you. Regardless of height. Suppose you're on a balcony, overlooking a courtyard. A chaingunner is on the wall on the other side. A swarm of demon is growling below, under and just in front of your position. The chaingunner won't hit you, he'll hit the demons. An imp next to the chaingunner, though, will not miss in the same hilarious way because it'll aim its fireball vertically as well as horizontally, instead of only aiming horizontally and letting the bullet find the nearest shootable thing regardless of elevation.

So from all these considerations, it appears that:

• Hitscan are a large part of the player's power. Along with unmatched mobility, it is what let the player be a one-man-army. Monsters can't dodge player attacks.
• In standard circumstances (i.e.: not the player teleported with his back to a firing squad of a hundred chaingunners who can see him through a 1-pixel tall window masked by an opaque midtexture in complete darkness), the enemy hitscanners aren't that big a deal

[Ed the Bat]

Finally, hitscan enemies will hit other enemies that stand in between them and you.

Not to mention the fact that hitscans are exempt from the rule of not hurting one's own species, unlike projectiles, allowing for more infighting opportunities.

[Ethril]

--a room full of lowly Troopers can be one of the roughest encounters available, primarily because of the fact that their weapons are entirely hitscan.

A room full of hitscan enemies usually just results in infighting, really; Map31, for instance, is actually easier on UV than HMP because the Nazis are placed in 2x2 bunches which guarantees at least two of them are going to get teamkilled.
A firing squad-esque row of them, on the other hand, can be deadly (or you could kill them all at once with a rocket or two before they even get a chance to fire). An open area with them scattered around isn't outright lethal, but you're practically guaranteed to take some shots. For some reason, a lot of mappers seem to love putting tons of zombies together with damage floors and almost no health/armor (A COUPLE OF HEALTH BONUSES (bonii?) IN THE CORNER ISN'T ENOUGH, GUYS. Give me some friggin' medikits already. Or a Sphere that doesn't unleash twenty billion Archviles and Cyberdemons.)

[Gez]

(bonii?)

YOU HAVE AROUSED THE WRATH OF THE GRAMMAR NAZI who hasn't even ever studied Latin

Some but not all Latin words with ending in -us change it to -i in the plural. Note: -i. Only one I. Where do these -ii come from, then? Simple: from words that have -i in the singular. Like genius. Genius, genii. Because there's already an I in genius. But you don't have an I to begin with? Then don't put two of them! Alumnus, alumni.

Now about that "some, but not all" thing. Virus is a mass noun. It is effectively already plural in Latin. Do not ever give it a Latin plural. You want to pluralize it, use English plural: viruses. Octopus is a Greek loanword, the plural is octopodes. (Some dictionaries will tell you octopi is the plural, but they are written by descriptivists. Feh. Just because the majority of speakers uses it wrong doesn't mean you should say they're right! Do we have an emote of a grumpy old geezer beating someone with a ruler?) Corpus, opus, genus have plurals in -ora, so corpora, opera, genera. Apparatus, hiatus, lapsus, nexus, plexus, sinus, status, and some others have their plural in... -us. So you don't change their spelling when pluralizing them.

As for bonus? If you don't want to use the perfectly serviceable regular English plural "bonuses", then you may use "boni" with only a single i.

[Ed the Bat]

YOU HAVE AROUSED THE WRATH OF THE GRAMMAR NAZI who hasn't even ever studied Latin

To be specific, it would seem this rant is focused primarily on the subset of grammar known as morphology. And personally, I think "The Morphology Nazi" has quite a ring to it.

And boy howdy is this getting off track. So yeah, bullets. I honestly think both hitscan and projectile attacks have their place. All comes down to the situation and the intended effect.

[Ethril]

(bonii?)

YOU HAVE AROUSED THE WRATH OF THE GRAMMAR NAZI who hasn't even ever studied Latin

In my defense I had a question mark there. >_>

[TheMightyHeracross]

Dude, he's playing around.

[Matt]

Worst thing about (fast)projectile bullets is that you're stuck with a minimum radius and height of 1, which seems very small when you're used to normal Doom projectiles until you do a few comparisons and realize it's bigger than some old medieval/early modern lead balls. (assume 56 units = 6 feet. 1 foot = 9.3 DUs. Horizontally, 1' is closer to 16 DUs, so your bullet is more or less a big 1" cube!)

This is badly noticeable when you're trying to do precision shots from behind cover, hitting corners where you could have sworn you were clear just based on your gun sprite and crosshair.

With a non-fast projectile you need to increase those measures to 2 to keep the projectile from glitching out, meaning your gun is now shooting bullets roughly the size of a small grenade. But then, if your "bullets" were slow enough to safely use a regular projectile actor you're probably not aiming for any significant level of verisimiltude anyway.

[Xaser]

TerminusEst13's post is probably my favorite post on the forums right now. Right on!

But yeah, on top of the "most attacks are projectiles you can dodge" stuff, Doom strikes a nice balance with hitscan monsters as well, having them either be physically weak (thus turning things into a "be quick and shoot first!" situation) or an actual boss monster (where the hitscannical dangerness is justified by the fact that it's a big guy that's meant to kick your arse). That and there are so many cool ways to evade the hitscan hordes besides ducking behind cover, e.g. running really far away, shooting the crowd with a rocket, maneuvering yourself to place a hapless bystander between you and them, run INTO the crowd to make them start shooting each other (though this is actually more of a suicidal co-op Xasertactic), and so on. You still get the speed benefits, and you just can't do that sort of cool stuff in the slow-player, hitscan-heavy modern world.

This is basically just aggregating what folks have already said, but 'tis a fun point to talk about, anyway.

[edward850]

(though this is actually more of a suicidal co-op Xasertactic)

You mean outside of chainsawing barrels and telefragging innocent civilians?