After this year’s E3 it’s clear that every platform developer is looking to add some form of motion control to their system, with complete 1:1 correlation between input and output being the apparent holy grail.
The potential various implementations are fascinating, however I have some usability concerns regarding the concept of motion control itself, specifically the desire to completely map input to output.
In it’s current incarnation the Wii is able to turn my uncoordinated and inelegant flailing in smoothly animated movements that make it look like I actually have a clue how to use a tennis racket or golf club. This ability to amplify and correct my input, making it representative of something much more elegant is vital to the appeal of games; nobody plays a game to look inept. Do we really want our every ill judged and inexperienced motion to be translated directly? Isn’t part of the fun of a game that it is a simulation of reality not a direct emulation of it?
I think this is potentially much greater issue than simply getting embarrassed when we fail to effectively swing a tennis racket. All the current implementations of motion control, including both those now available and those only recently announced, have one thing in common: they fail to take into account the affects of weight and resistance.
Consider how we interact with objects in the real world. If I pick up a golf club, the ways in which it can be used, the manner in which I can move it, is different to that of a tennis racket or a sword. Each of these objects has certain physical constraints limitting which actions are possible; how fast and accurately they can be wielded. I am able to swing both a golf club and a sword but the relative size and weight of each affects the control I have over the speed and power of that swing; the extent to which inertia and air resistance affect them is different.
If I am using some form of motion control device, or even my own hands, to represent a golf club or sword the degree of control I have over my swing is going to be very different. The controller will likely be both lighter and smaller than either the sword or the golf club and so my swings will be much faster. This lower mass will also mean less inertia so I will be able to perform more accurate and precise motions.
Having spent our entire lives interacting with the real world we have all developed an inate understanding of how objects of varying sizes and weights will react when we pick them up, swing them, or otherwise attempt to manipulate them. This inherent understanding of the physical constraints an object posses is reinforced when we actually attempt to interact with it. It’s unlikely anybody, with experience of both objects, would attempt to swing a sword like a golf club. If they did somehow believe that this was a feasible and practical thing to do the moment they picked up the sword theywould understand why they would be unable to do so effectively, and why attempting to do so would be dangerous.
We understand the physical constraints of the world we live in and expect objects to react in certain ways.
When we are using a gamepad, or other indirect interface device, to wield a sword or a golf club there is a clear level of abstraction between input and output. This abstraction means our preconceptions do not exist, we don’t know the manner in which our inputs are mapped to our outputs, so we have no inherent expectations of how a movement of a thumbstick will relate to the swing of a sword or a golf club.
When we have a motion controller in our hands the level of abstraction between input and output is still present, because after all we are not actually holding a sword, or a golf club. However compared to using a gamepad there is a much greater correlation between input and output which leads us to logically expect any motions we make to be translated accurately. A direct 1:1 mapping of input to output leads to unexpected behaviour. The input we supply leads to the correct output for the motion controller itself as it’s movement is governed by the laws of physics, but the output of the object we are manipulating in the game world could be radically different from the output we are experience from out senses and that which we have been conditioned to expect.
The closer we get to a direct mapping of input to output the more noticable the dichotomy between physical movement and representation movement gets; it’s an uncanny valley for user interfaces.
If you use a motion controller to represent the movement of a sword then one of two things will happen.
- The sword will swing exactly as fast as the motion controller, which is much faster that a sword possible could in the real world. This will seem strange as our inherent understanding of the physical constraints of a sword will have led us to expect it to move in a specific manner. At the same time we will see the sword moving at a speed and with a degree of accuracy that is utterly unnatural. There is a disconnect between what we instinctively expect the output to be and what we actually experience.
- The sword will swing as fast as it should in the real world, which given its physical constraints will be much slower than that of the motion controller. This will seem strange as there is a distinct disconnect between our own movements and that of the object we are supposedly wielding.
Motion Controllers are seen as an effective means of lowering the barrier to entry of video games, they are less obviously intimidating than a standard gamepad, their use and means of operating often immediately obvious. The conceit that when I move this object I am holding, then an on screen representation of a sword or golf club moves exactly as the object in my hands does is a very appealing one. What is going to happen when full 1:1 mapping of input to output arrives and players begin to notice the dichotomy between what their senses are telling them is happening and what their conditioning is telling them should be happening?
When we use a gamepad we have to learn form a new conceptual model for how inputs map to outputs, this can be time consuming. When we are using a motion controller we might have the even more challenging task of unlearning a previously formed conceptual model.
I wonder if maybe I’m concerned about nothing, if the human brain is more than capable of assimilating this new mapping into it’s conceptual model of the world and if we will very rapidly lean to cope with the disparity between predicted and actual output?
On a curious side note there is one object for which motion controllers are absolute perfect, for which none of the stated concerns apply:
"An elegant weapon for a more civilized age..."
Since it is a fiction weapon (Look I won’t tell anybody if you don’t), there is no inherent understanding of how it is supposed to move. The blade itself is made of pure light so there is no air resistance, and the only weight that exists is in the hilt.
Tags: Game Design, Interfaces, Lightsaber, Motion Control, Project Natal, Wii
June 6, 2009 at 4:11 am
there is one problem with the lightsaber idea, while the ideal lightsaber exists as a weightless blade, (and as i understand the eu there is a counterweight in the top of the hilt), the action we have come accustomed to see on screen is developed with a weighted blade, so the perception of how it moves would be similar to that of a sword, but n e way.
I think moving into future generation of games, given an environment where the player is entirely, or partially submersed in the world of the game then game controllers could be made to mimic the movement of real life object, ie counter weights etc, so that the controller does actually feel like the object its supposed to (within reason). In the current incarnation of games this would cause a disparity between what we see in our hand, and what is actually there. ie the object in our hand feels like a sword, but looks like a wii controller.
In a virtual reality type set up, or alternatively an augmented reality, (where we see the lounge room we are in, but also see in our hand what we are actually supposedly holding) could eventuate and be the next, or perhaps a couple of generations away,. way of playing games. so not only can we mimic the objects we are holding in a physical sense to a degree of acceptable error, using counter weights and such, but then convince the brain that it looks like we are holding that object, that i beleive should be the ultimate goal