Remember, for one of the shortest jumps in the original (Dome of the Rock), we calculated Altair would need a pile three times as high and 41 times as large to stop the fall without Altair crashing through the cart and into the bricks below. So, “slightly larger” won’t cut it, unless for some reason Ezio is “vastly lighter”.

The Bureau’s mission: To needlessly expose the wide gulf between video game physics and the laws of the real world; to pursue, to a pointless degree if necessary possible, the logical extremes of any mathematical given; to ask the questions that do not really deserve to be answered; and as an ultimate, Quixotic pursuit, to finally define the real world value of one hit point. We do this in the name of science for all mankind.

Our first journal of study is hereby submitted, dealing with three metrics – weight, speed and momentum.

Dr. Owen S. Good
Director, Kotaku Bureau of Weights & Measures

WEIGHT
Game: Fallout 3
Test Subject: Vault Dweller

In an RPG, you’d expect to have some distorted encumbrance measurements. Players have been hauling around a full cabinet of arms, plus full plate armour, plus a spare set of armour, plus dual-wield crossbows, plus 500 bolts, plus turkey dinner, since this kind of game was played on paper. It’s why D&D invented the Portable Hole.

Fallout 3 measures weight in vague units of “WG.” Of any RPG that caps carrying weight, it seems to let you carry a lot. Like a U-Haul’s worth. In my latest game I deliberately created a guy with 4 strength because I wanted him to travel light and carry only that which was useful. But as you can see in this recent loadout below, I’m still stowing a spare set of recon armour in case a Glowing One makes me dump in my Brotherhood suit.

Weapons: A3-21’s Plasma Rifle, Combat Shotgun, 28 Frag Grenades, 15 Frag Mines, Mesmetron, 3 Plasma Grenades, 4 Plasma Mines, Plasma Pistol, 9 Pulse Grenades, Scoped .44 Magnum (56 WG)
Apparel: Enclave Officer Hat, Power armour, Power Helmet, Recon armour. (71)
Aid: Blood Pack, 9 Buffout, 3 Dirty Water, 14 Med-X, 15 Mentats, 2 Nuka-Cola Quantum, 4 Psycho, 17 Purified Water
9 Rad-X, 25 RadAway, 6 Stealth Boy, 79 Stimpak, (sue me, I’m a HP whore), Sugar Bombs. (28)
Miscellaneous: 16 Bobby Pins, Carton of Cigarettes, Cherry Bomb, Conductor, Fire hose Nozzle, Ink Container
Leaf Blower, Pack of Cigarettes, 5 Pre-War Money, 12 Scrap Metal, Key ring with 14 keys on it (29)
Ammo: 202 rounds .44 magnum, 20 darts, 285 Energy Cells, 50 Mesmetron Power Cells, 493 Microfusion Cells, 280 Shotgun Shells. (0 WG)
Total WG: 184

What bothered me about Fallout was not so much that the heavy weapons, like a Flamer, weighed only “15.” Maybe they’re made from futuristic lightweight metal. No, it’s more that a pair of freaking TWEEZERS was equivalent in weight to a motorcycle helmet. It’s not even that the WG figure represents a total encumbrance factor – that either the item’s size or fragility makes it difficult to carry – because a pool cue has the same WG figure: 1.

So I chatted up Todd Howard of Bethesda Softworks, Fallout 3’s game director, about this. First off, is “WG” equivalent to anything?

“Not really,” Todd said. “It’s sort of close to pounds, but we intentionally don’t really say what it is. It actually started based on the weights we used for The Elder Scrolls, which most people don’t know are the also-amorphous ‘stones.’”

OK, fine. If they didn’t peg WG to something, I will. And I’m going to base it on the weight of beer. A bottle in Fallout is 1 WG. In real life, a bottle of beer, depending on how stout it is, will weigh roughly three-quarters of a pound when you figure in the glass. By figuring my total burden as it relates to at least one item in my possession, I could start imagining how large a load I was carrying around.

But what I couldn’t measure is ammo, meds and chems, which have no weight value – and I wasn’t going down to the local needle exchange to weigh whatever approximates a Jet syringe. Why didn’t Bethesda give them a weight? Because in the game, these are very valuable items. Why wouldn’t an RPG, which is more based in realism and more dependent on choice-making than other genres, also require players to be more conscientious about what they’re carrying?

“In regards to ammo and money, it’s just too granular a decision for the player, if they had weight,” Todd said. “You don’t want to make that a choice for the player; he already has to manage so much in his inventory and you need things he can find that are an instant win – ammo, money, drugs, etc, things that help keep him alive and playing. It would just bog the game down too much to find ammo and be thinking, ‘Do I want to pick up two of these bullets or the whole stack?’ We felt that decision should be on [which] weapons to carry, not what ammo.”

Yes, but when a Gatling Laser weighs the same as a frosty 18-can fridge pack of Miller, your decision to carry two is not because of their combat utility but the resale value in Rivet City. Todd said that’s entirely valid reasoning, and strength is meant to enable it.

“Much of your character’s power comes from his stuff. The more he has, the better he is. Even if he’s not using it, it becomes money,” Todd said. “Players get pretty good at the value versus weight game quickly.”

You might figure that, in the long run, it all balances out. Tweezers are overweighted, bazookas are underweighted, and everyone gets along. But my previous loadout would weigh 138 pounds (1 WG = 0.75 pounds) and still fill up a Public Storage room. Todd insisted that developers discussed the question of how much a player should be able to carry, “right until the end. … We kept narrowing and narrowing what a low-strength versus high-strength gave you, because it was too powerful.”

Was too powerful? In the finished game, a Fallout 3 character with the bare minimum strength of 1 can carry 160 WG. I searched for a real world comparison, and this is the best I could do: The Improved Load Bearing Equipment in use by the U.S. Marine Corps since 2005 can carry – ready for this? – 120 pounds. If beer is our unit of measure (and why shouldn’t it be?) that converts to 160 bottles of beer (or WG). In other words, any vault reject a notch above total weakling – a 2 strength or better – will out-lug any Marine, even the one assigned to carry the mortar and shells.

Partly to spite Bethesda, I created a character with 1 Strength and assigned the rest of the points to more useful attributes. I never use melee weapons, anyway. I also manually assigned weight to my ammunition and chems (1 for units of 10). I quickly saw how right Todd was.

In Fallout, your ability to meet more difficult challenges depends a lot on the equipment you have, and it’s usually items you build or buy that prove the difference. Financing that comes from the resale of surplus items, not the discovery of treasure. Realistic strength would leave you endlessly grinding before starting the next job.

As for ammo, I gave up on that shortly after a raid at the Super-Duper Mart. I was robbing Raider corpses for spare rounds to fight off the survivors and writing down the totals. It was indeed too granular a decision, and got in the way of more pressing challenges.

So, even though with a 5 strength, you can run from Megaton to the Arlington Public Library loaded down like a Peruvian donkey, let’s just say the future is made of super-light plastics. And the radiation turned everyone into Lou Ferrigno.

[Images from the Fallout Wiki]

SPEED
Game:Grand Theft Auto: San Andreas
Test Subject: Carl “C.J.” Johnson

Originally, I wanted to test the scale speeds of the Team Fortress 2 characters, especially Scout, who could probably outrun Carl Lewis like a Porsche outruns Stephen Hawking. The problem with this, as with other games, is measuring the distance those guys cover in real world units. I’d have to know, say, Heavy’s IRL height (6′5?”) and be able to lay him end to end over a straightaway to get its real distance. I’m not a modder, and I wouldn’t have that kind of time anyway.

So I then looked to the Grand Theft Auto series. From Claude to Niko, you’ve always had the ability to overtake a moving car on foot and jack it. I really wanted to know these guys’ running speeds, and they live in cities with structures based on real world ones. Unfortunately, everything in Liberty City is a compressed distance, so running Niko across the Broker Bridge still wouldn’t tell us much.

But in Grand Theft Auto: San Andreas, there’s this Easter egg, which identifies the specific dimensions of the Gant Bridge, including a length of 159.7 meters. During the first few tests, something seemed way off. First, 159.7 meters isn’t even a 10th of a mile, and C.J.’s runs – at a sprint – were keeping up with traffic and returning mile times of 17:41. So I had to measure this bridge for myself. If I knew the actual scale speed of a vehicle in the game, I could derive its length. This database lists all such attributes.

Thus aboard an NRG-500 motorcycle running at its top speed of 118 mph, I made five maximum-speed trips across the bridge, at a flying start, with a median time of 18.15 seconds. If the Gant Bridge really was 159.7 meters, the bike would have been doing 20 mph, not 120 mph. It’s possible they’re talking about a distance shorter than the one I was using – toll booth in San Fierro to concrete strip at Tierra Robada – but at top speed, the bike should be able to cross 159.7 meters in just under 3 seconds. Either way, 160 meters is a fraction of the bridge’s length as it relates to C.J.

So, at top speed, the bike is travelling at 173.16 feet per second. Multiplied by 18.15, we discover the length of the Gant Bridge is 3,142.85 feet, which is nearly 1 kilometer. As another control, I went back and rode with traffic, matching its speed. We crossed the bridge in 1:09.16, which is 30.98 miles per hour. I damn for sure could see a developer setting standard traffic speed to something round, and 31 mph is almost 50 kph. So, I’m pretty confident the sign is incorrect, and I got this measured as close as possible.

Now, back to running it. C.J. has five paces on foot: a walk, a “brisk walk,” a “jog,” and then two sprints, one with the A button held down, and another that provides a burst of speed by rapidly tapping it. The C.J. I was playing had maxed all of his physical stats, so he could achieve top running speed and not tire out, at any distance. Back at the bridge on foot, I took him through the five paces.

Walking
At his slowest C.J. covered the distance in 8:22, which equates to 4.2 miles per hour. Frame of reference: 4.0 is the fastest most walk on a gym treadmill. At the “brisk walk” pace, C.J. covers the distance in 4:44.03. Remember our treadmill? This “walk” is more than a jog, it’s 7.54 miles per hour. It’s equivalent to a 7:57 mile time. My best time in the mile – running – is 8:21, five years ago.

Running
Now it gets good. At the third pace, “jogging,” C.J. crossed the span in 2:43.16. If he held that pace he would run a marathon in under two hours, which is unprecedented. Holding down the A button, C.J. crossed the bridge in 1:38.11, or 21 miles per hour. That’s a mile in 2:44.84, which is inhuman. Remember Roger Bannister? The first mile under 4 minutes? C.J. would run the first one under three. He would beat the world record holder by a larger margin (in seconds) than he would have lost this year’s Kentucky Derby.

Sprinting
Rapid-tapping the A-button gave C.J. just a 16- second advantage, which means this loses its effect pretty quickly. Still, at minimum one can assume some world-class sprint times. How world class? Try torching Usain Bolt’s records in the 200 and 100 by two and one seconds, respectively – 17.1 and 8.58 seconds. Granted, that speed figure is derived from a running start. Real-life sprinters have to react to a gun and get up to speed. But, remember, C.J.’s sprint lost effect, I’m not sure exactly how far in, so most of this time was derived from a run at the standard “A” pace.

Incidentally, C.J.’s motion capture actor was Eddie Goines, a star wide receiver at North Carolina State University and a classmate of mine. I knew him pretty well, as well as a sports writer knows one of the team’s stars, anyway. As a flanker, he set all the receiving records that Torry Holt and Koren Robinson would later break. As a freshman, Eddie was the fastest on the team, clocking a 40 yard dash in 4.35. A 4.09 is thought to be the NFL record. CJ’s time is 3.15. I’m sure Eddie would be delighted to know that, at least in a video game, he’s by far the fastest human alive.

MOMENTUM
Game: Assassin’s Creed
Test Subject: Altair

No one would expect to fall 40 stories onto the top of a parked car and survive. However, at least it stops the body from crashing all the way through to the ground. Now imagine falling that height into a pile of hay that’s roughly 2 meters wide by a meter and a half tall.

That’s the first “leap of faith” in Assassin’s Creed, from the tower at Masayaf. Holy catfish, that poor bastard who jumped with Altair at the beginning was lucky to get off with just a broken leg. And it is far from the steepest drop in the game. The infamous steeple on the cathedral at Acre is nearly twice as tall. Fresh off our victory in San Fierro, the Kotaku Bureau of Weights & Measures set out not only to fix its height, but also to calculate how much hay you’d need to land safely.

Ubisoft verified that Altair’s height and weight, for purposes of the game’s physics, was 6 feet and 190 pounds. This would be useful in calculating his stop. But that’s all we got from them. However, one of the locations in the game is Jerusalem’s Dome of the Rock, whose dimensions are known. The structure’s walls are 11 meters tall. Putting all this information in the hand of a trained scientist – devoted reader Matt M. – we were able to come up with some good estimates.

Matt worked up all three heights, but let’s use Acre’s as it is the most impressive. We were able to time the drop from the top of the steeple -4.1 seconds – using this video (which I downloaded and measured frame by frame). Working backward, we found that its real-world height would be 82.37 meters – about 270 feet. In the game, Altair is accelerating to 39.69 meters per second, acquiring a momentum of 3,420.48 kilogram-meters per second.

That’s certainly a large number, but what does it mean? Matt breaks it down:

Basically, whatever catches him has to has to reduce that momentum to zero in under 0.05 seconds, which is the difference in time between Altair falling 82.05 meters and falling 80.05 meters at that speed. That means in the space of 2 meters – which is a little lenient since the floor of the cart is, what, half a meter off the ground? – the hay has to provide 68,298.25 Newtons of force. It’s 136,596.5 Newton meters of work, which is a ridiculous thing to ask of hay.

Certainly, Kotaku Weights & Measures does not want to be unreasonable in its dealings with dead vegetable matter. And I’m not sure what could provide that kind of stopping power in that space, other than Kevlar. Or pavement. So I asked Matt if he could figure how large a haystack would be required to cushion a fall from such a height. We used the elasticity of military-grade bungee cords as a guide (using specs found here).

In the case of Acre, the haystack would be so big it would dwarf most other buildings in the game – 40 meters (131 feet) at its point, 67 meters (219 feet) wide at the bottom, if the dimensions conform to the original tiny pile. The freefall into such a mass of hay would last only 2.87 seconds. In terms of volume, it’s more than 2.7 million cubic feet of hay – 2,695 times greater than what Altair is leaping into. I kept picturing Phil Hartman sitting atop the amazing mountain of Colon Blow cereal.

Alongside this you can see comparisons, to scale, of the heights Altair falls at the Dome of the Rock, Masayaf, and Acre, and of the size of hay he hits in the game relative to the size he would need to survive. “Leap of Faith” indeed. Sounds more like Altair’s in a suicide cult.

The Kotaku Bureau of Weights & Measures gratefully acknowledges the contribution of Matt M. to this post. Follow him on Twitter.

The new physics engine for EA’s Fight Night Round 4 brings you closer than ever to the true experience of having your head sliding against a large sweaty man’s armpit.

It’s all well and good when demonstrating boxing with a bald guy. What I was to see is real-time hair deformation as it slides underneath your opponent’s underarm, perhaps with a little hair-hooking, just in case the other boxer didn’t shave recently. Only then will I be truly impressed. Until then, I’m only slightly impressed.

Last night, Media Molecule’s David Smith accepted four awards for LittleBigPlanet at the Game Developers Choice Awards. I’m amazed he’s awake enough to lecture on the game’s physics this morning.

Here are some key insights Smith had into the challenges of making a game where physics is everything and logic is next to nothing:

“I think what a lot of people mean when we talk about physics in games [is that] it’s more complex, emergent phenomena… that we’re trying to use in LittleBigPlanet. You can make things seemingly more complex than the sums of its parts.”

You need good physics in a game, Smith said, because “it helps you to suspend your disbelief in the world around you.”

It’s not enough to just have ragdoll physics. Smith says that “developers feel you can somehow get something for nothing” by going this route, but they’re actually making their game suck by not taking into account all the things that can go wrong with ragdoll deaths.

In LittleBigPlanet, the challenge of physics was all about letting things go wrong — within a certain stretch of reason. Having the world be 2D instead of completely 3D allowed Media Molecule’s physics engine to handle a certain amount of chaos without creating an environment where everything could lead to a crash.

“If you really need to have all that strong control of what the player’s doing,” said Smith. “You probably shouldn’t be using physics.”

Beyond that, it was all about finding out what the Sackboys could and couldn’t do. This was a lot harder than just letting the characters run around in the environment because the development team found that there was a conflict of interest between what people knew they could do in real life and what they thought they could get away with in the game.

“You don’t really think people can change direction in mid-air, do you?” Smith asked the audience.

I was about to raise my hand, but he changed slides to talk about how things like “air control” (where, yes, Mario can jump several times his own height and change direction mid-jump) and other video game expectations got in the way of LittleBigPlanet’s physics engine — particularly when level designers bought into the expectations.

“A level designer’s expectation is that a jump will take you to the same height no matter where you do it,” Smith said. “So you have this situation that’s kind of unpalatable to level designers [like] flipper objects that — if you jump when that flipper is turning — [propel you] very high into the air.”

Smith says he got around that particular snag by programming the Sackboys’ legs to bend when they hit the flipper — like you’d do in real life to absorb the impact of something coming at your feet really fast.

“Shit happens,” said Smith said, rounding out the talk. “More games should consider embracing the chaos of physics. There are problems, but they can be creative opportunities.”

And it’s this kind of thinking that rakes in the statuettes. Take note, kids.

Physics games are like National Geographic maps. I could stare at them for hours and feel like I learned something even if I couldn’t articulate what I had been doing all this time.

This is Ball Droppings, which, despite its unfortunate name, is a good way to kill time before dinner if you’re bored with surfing the web and don’t feel like firing up your console for just 20 minutes. The premise – balls drop from a point on the screen, and you create boundaries off which they rebound. When they do, depending on the ball’s speed, it creates a tone. It’s an experimental game/application for Google’s chrome browser but it works in most anything.

You can mess with the gravity and the drop rate to create some spooky-sounding tone patterns. Once I replicate the Close Encounters of the Third Kind signal, I’ll move on to something else.

Balldroppings [Site]

An OLPC Jam is a sort of intense workathon where developers, artists, and other ‘creatives’ throw themselves at a problem over a short space of time. Previous Jams have created educational and medical resources for use with the OLPC in developing countries and the organisers are confident that the talented geeks putting themselves forward for the Physics Game Jam will come up with something special.

All the code will be open source, so it is not impossible that the games created in the Jam will see the light of day in web-based games or other platforms down the line.

If you have any coding, game design or artistic chops and fancy helping out, get in touch here. There are prizes — including XO laptops and other goodies — for the best creations, plus a lovely warm feeling from helping a good cause.

OLPC Physics Game Jam For an XO [Slashdot]

“We’re deeply impressed by NVIDIA’s commitment to push physics to new levels of fidelity and performance, and their investment in development and support infrastructure across all platforms,” said Torsten Reil, CEO of NaturalMotion. “NVIDIA’s PhysX technology provides a robust, high-fidelity foundation for our advanced character animation algorithms and tools. Through our close collaboration, we will help game developers bring fully interactive and believable characters to a wide range of games.”

It’s two great tastes that taste real together! Hit the jump for more details on the partnership between physics powerhouses.

NaturalMotion and NVIDIA Bring a New Level of Realism to Games

Companies Team Up to Integrate Animation, AI and Physics Technologies

SANTA CLARA, CA and OXFORD, U.K. – June 11, 2008 NVIDIA Corporation (Nasdaq: NVDA), the worldwide leader in programmable graphics processor technologies, and NaturalMotion Ltd., the developers behind the highly acclaimed euphoria motion synthesis technology, today announced that the companies have teamed up to offer game developers and publishers easy-to-use, highly integrated solutions for adding animation and physics in next-generation games.

Starting with the upcoming release of NaturalMotion’s morpheme animation engine, NVIDIA’s PhysX technology will provide rigid body dynamics functionality across its product portfolio, supporting both console (PS3, Xbox 360 and Wii) and PC platforms. In addition, PC titles will benefit from GeForce GPU acceleration for both PhysX and future versions of morpheme, bringing additional motion fidelity to the PC game experience.

“We’re deeply impressed by NVIDIA’s commitment to push physics to new levels of fidelity and performance, and their investment in development and support infrastructure across all platforms,” said Torsten Reil, CEO of NaturalMotion. “NVIDIA’s PhysX technology provides a robust, high-fidelity foundation for our advanced character animation algorithms and tools. Through our close collaboration, we will help game developers bring fully interactive and believable characters to a wide range of games.”

“The introduction of NaturalMotion’s AI and Adaptive Behaviours is the next big breakthrough in gaming,” said Roy Taylor, Vice President of Content Relations at NVIDIA. “This technology takes us into a new level of immersion as characters roll, jump, duck and react to the players’ actions and the environments around them. We are delighted to be working with NaturalMotion to bring this new level of character animation to the world.”
For more information, visit www.naturalmotion.com.

Half-Life Havoc (HLH) is a lesson in video game physics created in Half-Life 2 using the included level editing tools. Taking inspiration from games like Garry’s mod and Portal, HLH aims to create an environment where players can take some time to appreciate the complex physics simulations that are present in modern games. HLH is made up of a series of rooms, each of which has a puzzle or game that illustrates a feature of Half-Life 2’s physics engine. Commentary nodes spread throughout the level teach the player about what is going on in each of the games and gives insight into video game physics.

In addition to the mod, you can find their essay entitled “Playing Dead: Physics in Pop Games”.

Half-Life: Havoc

Not precisely a game, but there has been talk lately of physics (and science in general) in games, and this is a neat little program that’s fun to spend a while playing with. It’s still in beta and has the requisite bugs you might expect, but here’s what the creator has to say about it:

Phun is a Master of Science Theises by Computing Science student Emil Ernerfeldt for supervisor Kenneth Bodin at VRLab, Umeå University. The solver is based on work by Claude Lacoursière

Phun is meant to be a playground where people can be creative. It can also be used as an educational tool to learn about physics concepts such as restitution and friction.

You can snag the download (Windows only for now, but an OSX version is apparently on its way) at the Phun website, where there’s more information. There’s also a thread going over at the GameDev.com forums.

Havok Gives Artists Unprecendented Control With Introduction of Cloth and Destruction

SAN FRANCISCO, Feb. 19 /PRNewswire/ — Havok(TM), the premier provider of interactive software and services to digital creators in the games and movie industries, today unveiled Havok Cloth(TM) and Havok Destruction(TM) at the 2008 Game Developers Conference (ES162, West Hall). Available for the first time in mid-2008, these two products provide artists with dramatically increased control over interactive cloth and destructible objects within games.

Built on Havok’s award-winning modular suite of run-time technology and artists tools, Havok Cloth(TM) and Havok Destruction(TM) will feature out-of-the-box integration with Havok Physics(TM) and Havok Animation(TM), dramatically accelerating the development of cross platform, cutting edge electronic entertainment across all leading game platforms.

“With the release of Havok Cloth and Havok Destruction, the company adds both depth and breadth to our market-dominating suite of physics tools,” said David O’Meara, Managing Director of Havok. “Innovative and easy to utilize, Havok Cloth and Destruction are powerful, flexible tools giving art teams more control in the design process, resulting in a more realistic interactive experience for gamers.”

David Coghlan, Vice President of Development for Havok said, “Havok Cloth and Havok Destruction will further increase the standard of realism and immersion in games. Havok Cloth enables scalable clothing that will significantly enhance the visual impact of on-screen characters. Havok Destruction will drive high-adrenaline action scenes with unprecedented levels of physics mayhem.”

Havok Cloth(TM) is a new performance-optimized development tool designed to minimize the time that game artists spend on animating the behavior of character garments and environmental cloth. It enables increased realism for cutting-edge games, is easily customizable and fits into today’s workflow without burdening artists, animators or programmers.

Havok Cloth(TM) features:
— Highly realistic physically-based simulation of cloth and character
clothing with low CPU and memory overhead
— Multithreaded and platform-optimized (including PLAYSTATION(R)3)
— Artist-driven control of the full range of cloth behavioral properties
such as stretching, damping and bending
— Artist-friendly, modeller-based, cloth setup tools

Havok Destruction(TM) is the cross-platform tool for simulation of rigid body destruction. Destruction gives the game artist total control over the simulation, drastically reducing the production time and cost of creating large numbers of realistic destructible game objects. Havok Destruction can create a completely new game play experience by giving additional realism to structural mechanics, graphical effects and game level design.

Havok Destruction(TM) features:
— Dynamic fracture of game objects including: shattering, fracture and
deformation.
— Software Development Kit that is fully multithreaded, optimized for
the PLAYSTATION(R)3 and Xbox 360(R) and makes optimal use of Havok
Physics
— Art Tool Support