Dying from 3.5 blocks high fall feels a bit overkill

Ferarn shared this feedback 5 years ago
Submitted

The difference in speed differences between some damage versus full health is so small that basic gravity has one die from a 3.5 block high fall at full health, or only get 11 damage depending on the angle that you dropped off the block.

Replies (5)

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I don't think the game calculates falling damage, I think the only damage is based on collision speed.

Also each block is 2.5 meters in height, or 7.5 feet.

3.5 blocks high is equivalent to almost 29 feet.

Falling three blocks vertically is the equivalent of falling off a 2 story building. Based on how you fall, you could very well be dead.

However, I do agree that there is something wonky about the damage calculation when angles are involved.

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Actually, 2.5 meters is just shy of 8 feet 2 and a half inches. But your end result of almost 29 feet for 3.5 blocks is correct. For any reader who doesn't know, an inch is defined as exactly 2.54 centimeters by current standards so conversions with a calculator are pretty straight forward. Or use Google by searching for "2.5 meters in feet" or "2.5 meters in inches" or even "(3.5 x 2.5) meters in feet" (that's 3.5 blocks that are 2.5 meters high and it gives the result in feet). The Google search engine is awesome.

But the basic point remains. Its a 2 story building. This makes sense since one block high is high enough to walk beneath and still be able to jump. It's just that the roof is extraordinarily thick. Seriously, having 2.5 meters between each story is, well... excessive, but that's just how this kind of game works.

As for a slight change making a huge difference, that's because energy increases with the square of velocity.

I suspect the wonkiness with angles is to differentiate damage done to head and damage done to the feet, but that's just a guess. I don't doubt it could be improved, but is it worth it? You might argue that the head wasn't hit, but the simulation also doesn't have you fall over when you land at an angle, which is what would happen, and you'd probably hit your head in the process.

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I know the math, it's just the issue that going from slight/no damage to fully dead with barely any leeway is a bit unbalanced. The height that would break an ankle vs break a spine isn't going to be a couple inches or feet difference, unless you're very unlucky on how you fall irl, lol. Even irl two stories isn't going to kill you if you land on your feet, just severely hurt and break some bones. And ingame there's a suit which could be implied to have some armor and shock absorbance to provide a bit more room for error.

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Actually... I implied something incorrect about the energy and I feel I should admit it. I was in a rush that night to go see some friends and hadn't thought things through. Later (during my drive) I realized my mistake (and I'm embarrassed because it's a freshman level mistake).


Although the energy increases with the velocity squared because you are accelerating you get to the ground sooner than if your velocity was constant. As a result, energy actually increases linearly with height. E = mgh where m is the mass, g is the gravitational constant near Earth (or 1g from a gravity generator in the game) and h is the height. I won't bother with the derivation since this equation is well known or with generalizing to different values for g because it doesn't tell the whole story anyways.


The consequence is that damage should also scale linearly with height starting with zero at some height and stopping at some other height due to terminal velocity being reached (assuming an atmosphere). Now, as to what point it should start and how quickly it should increase, that's a more complicated matter and you're probably right. *For a game* two stories high is probably about where the chance of a small amount of damage should begin and the chance of damage and the amount should probably increase to near certain death at some height. I say for a game because even much shorter falls can injure or kill someone in real life, but that wouldn't be very fun for a game.


But what height should be deemed almost always fatal? Well, there is no height at which a fall is *always* fatal in real life, just highly probable. An extremely significant factor is what you fall on (not what part of your body but what object stops your fall). I found a paper from NASA on the subject (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930020462.pdf) and they state on page 8 that impacts at terminal velocity on snow have been tolerated without serious injury (though I imagine that's only sometimes true). That paper is interesting because it provides numbers that relate the effects of impacts at an angle to feet first impacts. Note that you reach terminal velocity after a fall of about 450 meters (180 game blocks) in Earth's lower atmosphere.


The reference that I found most cited though was "Trauma Anesthesia" edited by Charles E. Smith. It states that 50% of people die when falling from 4 stories (which is stated as being 48 feet which is almost 6 blocks in the game) and 90% of people die when falling from 7 stories (which I then take to be 84 feet which is more than 25 1/2 blocks in the game). Of course, this is an average across many varying conditions which affect the probability so the first statistic doesn't mean that you have a 50% chance of surviving a fall from 4 stories onto a hard surface. Most of the people who survived such a fall probably fell onto a soft surface or had their fall broken by something that absorbed some of the energy.


Still using this information it's possible to create a more realistic simulation but I doubt that will happen. It isn't important enough to the game. But you would definitely seem to be right about an almost 9 meter fall almost always killing someone. Though at that height you are almost always looking at some serious injuries even if you survive. Given the way various sources describe such injuries, someone falling from that height needs immediate medical assistance and is probably not going to be moving around on their own. So maybe it's not a bad cut off for a game in that regard.


Aside: While investigating this, I found an article on surviving very long falls (thousands of feet) and came across the following humorous quote about surviving falls from planes:


>> Rhett Allain, associate professor of physics at Southeastern Louisiana State University, says that experimental evidence on the subject is thin because it's unethical to throw people out of airplanes for science.


>> "Fortunately, we don't have enough data to make a trend line," Allain says.

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It's almost like we'd need MMO style statuses, bleed, root, etc to let you fall, break a leg and slowly drain health until death if you don't make it to a med bay.

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On Trauma Anesthesia: there are techniques for surviving falls taught in the military and to some civilian types, like skydivers. Making sure you don't land on your head is probably the first, then landing on both feet, and falling into a roll. So the survivability question is probably more about how they turned in the air after a fall than what they landed on. It could probably be reduced to figuring out: given X linear velocity, how much energy can be absorbed without critical damage to shift the direction of the velocity to a perpendicular direction. Though really its going to a circular direction, e.g orbiting earth really close.. :-D

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Awesome job on doing all that research, and I love that quote too, lol

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