The evolution of gravity in Mario games | Hacker News Reader

The evolution of gravity in Mario games

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40 pointspetercooper16 comments

The stats they have for Super Mario 2 stand out from the ones for 1 and 3. That's interesting because it wasn't originally developed as a Mario Bros game. It was originally released in Japan under the title Doki Doki Panic (I had to look up the name). The North American / European version of SM2 was a rebranded version of DDP. According to the stats in the article, Mario is taller and exposed to higher gravity than the other early games which sounds about right (the gameplay definitely felt different).

As a side note, I don't understand the title Mario Brothers. Are their full names Mario Mario and Luigi Mario? I'm not aware of any other brothers that take their common name from one of the brothers' first names.

> Are their full names Mario Mario and Luigi Mario?

According to Wikipedia, yes.

Oh yeah, it looks like they mention it on the entry about the movie. I don't see any mention of their full names on any of the game-related pages though.

Re-making old games used to be more common I think:

http://www.seanbaby.com/nes/atari2600.htm

No plot of Mario's position vs. time? They need to verify that their equation (x = x0 + v0t + 0.5at^2) accurately describes the fall.

It seems like this probably would have been more accurate if terminal velocity had been mentioned. I'm not sure if Mario would hit it on the scale they were working at, but if he does, that would certainly skew the results.

Also, it is interesting to note that the characters in SMB2 don't seem to have the same amount of gravity on them. (remember Luigi?)

This is an extremely poor analysis. It ignores terminal velocity, which is a huge factor, and it doesn't even acknowledge this in its "Sources of Error" section. The graph they produced is meaningless

Is terminal velocity relevant over a short drop? An explanation would be cool. I thought it wouldn't matter if the subject didn't actually approach that velocity (do you approach 120ish mph on a drop of several meters?).

But Mario's terminal velocity might be much lower.

Yeah, terminal velocity is relevant over a short drop if the acceleration is high and the terminal velocity is low (both true in mario)

Looking at the table they made, most of the falls are about half a second long. I'm too lazy to go test this but a lifetime of experience playing mario games makes me feel like this is far more than enough time to reach terminal velocity

You are bringing too much of your real-world common sense into this topic. Video games can do as they damn well please. I've played games where the profile of a jump is straight-line up, straight-line down, with no acceleration concept relevant at all, which also eliminates "terminal velocity" as a concern... it's just velocity, period.

Unfortunately, the same is true of the authors of this paper, who assume with no evidence, or perhaps rather against the evidence, that standard Newtonian formulas hold and therefore they can compute "accelerations" and such. Newtonian formulas do not hold in the Mario-verse, or in platformers in general.

(In some cases the real formulas may be modeled on Newtonian formulas, but the full set almost never holds, "equal-and-opposite force" in particular. Please note that citing a single counter-example is insufficient to disprove "almost never"; I can do that too, but it doesn't change the fact that most games use physics only loosely related to reality.)

I was shocked at the concept of acceleration for this very reason. I thought there was just velocity up and velocity down because I got my notions of physics from video games.

They wrote an article about gravity in Mario games and left out Mario Galaxy? That's a serious oversight, although perhaps the article predates it. Also, what's this "96-bit" nonsense? The Wii is a souped-up GameCube, so it should be very similar..

Does Mario not fall with a constant velocity? That's how I remember it.

This is interesting, if only a bit of fun... I would like to have seen an analysis of how quickly Mario decelerates when he is jumping up, as well as falling. Symmetry would dictate that g was the same in both cases although on the way up terminal velocity would not be a factor.

I can tell you how it works. You maintain your initial jumping velocity almost all the way up to the top of your jump. The peak of the jump occurs suddenly, and it's when you release the jump button or when the maximum jump-height is reached, whichever comes first. The maximum jump-height increases by a blockheight or two if you were sprinting when you jumped.

The only part that I'm not too sure about is what exactly happens to your velocity when you start to slow down at the peak of your jump. You might linearly decelerate like you'd expect from gravity, but it might be less newtonian than that; it's hard to tell just from the feel of the game.

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