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View Full Version : Final Fantasy (the movie) and zero G: Shouldn't Aki's hair b



Jigsaw
2002-Apr-08, 01:52 AM
There are a couple of scenes where she's in orbit in her ship, in zero G, and her hair, which is done in a smooth chin-length pageboy, is still a smooth chin-length pageboy. Shouldn't it be out around her head, given that it's zero gee?

Like this?
http://www.nasaexplores.com/lessons/01-044/images/bad_hair.jpg

Also, there's a short 1-second bit where the Evil General, also in orbit in zero G in a space station (I don't want to get into any spoilers here), pulls two big levers down at the same time, with both hands, like *ka-chunk*, and my son says that he should have been kicked backwards and upwards by the reaction. They're these two humongous levers, and he's kind of bending over a little bit (stooping over) to pull them both down from about shoulder height towards his waist-level, so The Kid says that he should have had his legs kicked out from under him, backwards, and upwards backwards (is this making sense?)

David Hall
2002-Apr-08, 02:47 AM
On 2002-04-07 21:52, Jigsaw wrote:

Shouldn't it be out around her head, given that it's zero gee?



Maybe she used crash-helmet-in-a-jar?



...so The Kid says that he should have had his legs kicked out from under him, backwards, and upwards backwards (is this making sense?)


Perhaps they were wearing magnetic boots?

Haven't seen it so I don't really know. But it sounds like your son has a good head on his shoulders. /phpBB/images/smiles/icon_smile.gif

Jigsaw
2002-Apr-09, 12:27 AM
If he was wearing magnetic boots, wouldn't they then have to show him paying attention to picking up his feet and putting them down again, like "clomp clomp"? Or have they improved magnetic boots since the last time I looked? /phpBB/images/smiles/icon_biggrin.gif


My hubby says the reason they didn't show her hair all around her head has nothing to do with "they goofed", and everything to do with the fact that "their target demographic--teenage boys--want their women to have smooth chin-length pageboys, not NASA Fright Wigs." /phpBB/images/smiles/icon_biggrin.gif

And he thinks it's hilarious that I'm quibbling over the accuracy of a CGI fantasy. "Honey," he says patiently, "It's a cartoon."

Simon
2002-Apr-09, 08:58 AM
On the hair issue, my first thought when I saw it was "I don't blame them. They must have had enough trouble rendering it in gravity; having it go every-which-way would have given their computers heart-attacks." /phpBB/images/smiles/icon_wink.gif

Mr. X
2002-Apr-09, 04:26 PM
I think it may be more mechanical than that about the hair. Most likely the number of polygons required to render the hair in the air (LOL! Awkward phrasing! /phpBB/images/smiles/icon_razz.gif), is simply unacceptable. It would take billions of megabytes of ram to keep so many polygons in place, not to mention lighting effects to be applied to each hair, and even if it's not real-time graphics, the amount of time to render it would be insane. If you have to add to that the behavior of each hair, (I don't know if this exists in movies or if it's just a bunch of polys) and maybe even collision detection, it makes absolutely no sense.

I have never seen anything of that "size" ever done in computer graphics. Best they can do in small areas is grass, otherwise the hair up idea is simply ludicrous computer-wise. /phpBB/images/smiles/icon_razz.gif

ToSeek
2002-Apr-09, 05:02 PM
You'd think there would be a better way of doing it than myriad polygons, like fractals or something. (I'm also thinking of the research that showed that flocking birds could be modeled very simply - not that hair would necessarily be the same.)

Chip
2002-Apr-09, 05:41 PM
On 2002-04-09 04:58, Simon wrote:
On the hair issue, my first thought when I saw it was "I don't blame them. They must have had enough trouble rendering it in gravity; having it go every-which-way would have given their computers heart-attacks." /phpBB/images/smiles/icon_wink.gif


One simpler method (in concept rather than execution) mixes old technology with new: they could of combined the impressive computer animation with an old fashioned "traveling matte" shot of a "real" actress's hair filmed in zero g, and then "matted" onto the character's head and it into the scene.

The film's storyline was a little out there and the animation was stunning to me, so I didn't notice the hair-staying-nice-in-zero-g scenes until they were pointed out here. /phpBB/images/smiles/icon_wink.gif

Donnie B.
2002-Apr-09, 07:05 PM
Maybe she was wearing a Devo Plastic Pompador (tm) or equivalent.

Mr. X
2002-Apr-09, 09:31 PM
On 2002-04-09 13:02, ToSeek wrote:
You'd think there would be a better way of doing it than myriad polygons, like fractals or something.


Unlikely, at least at the moment. Polygon (triangles) based graphics are at the very basis of CG, from games (consoles and PCs) to movies.

Automatic ways to "animate" are being found, such as skeletal animation (VALVe software were I believe the first to use it in their last and only game, Half-Life), but they are few and far between.

Remember also that the software engineers are not men, but super-men who can make sense of the most tangled, obscure pieces of logic known to mankind. In my own language I say they put the "ingenious" in "engineer" a play on words that actually works but not in english.

That is to say, had there been a more efficient way to do it (cost/development time/horsepower) they would have used it, but since they didn't it is only fair to assume there isn't, that is to say there wasn't, knowing the quality of the people who work on it. /phpBB/images/smiles/icon_smile.gif

Animation in real-time (as opposed to pre-rendered it is called if I'm not mistaken) in 3D has only just now begun to tackle the problem of hair and grass with nVidia's GeForce4 chipset, but I do believe I have readthey are still only very clever tricks instead of real grass blades models. In those tricks of course you can exclude collision detection in big parts, as well lighting effects on individual blades, something that would have been necessary in a movie like Final Fantasy.



(I'm also thinking of the research that showed that flocking birds could be modeled very simply - not that hair would necessarily be the same.)


That was not the point of the experiment if I recall correctly. The point was that with 3 simple directives a flock of birds (which I believe were called boids, you can find them easily on the 'net) can act almost exactly as would a flock of birds. If I remember the rules were:

1. Attempt to maintain a minimum distance from all other Boids and objects on the screen.
2. Attempt to match speed with other Boids in the neighborhood.
3. Attempt to move to the center of the Boids in the neighborhood.

Boids were an attemps to model flocks on screen quite succesfully. However they were strictly a behavioral experiment, as the boids themselves are simple, slightly deformed pyramids with 5 sides. Not exactly "demanding". /phpBB/images/smiles/icon_razz.gif

I believe the original boids were made in 1986, so you must be quite old to remember that. /phpBB/images/smiles/icon_smile.gif

Nevertheless, we were initially talking about rendering and high poly models and Aki. So the boids experiment is not really related to Aki... unless she moves towards the center of the flock of humans on the screen, matches flock velocity and keeps a minimum distance from other humans... /phpBB/images/smiles/icon_razz.gif

Please excuse my lackluster mastery of the english language.

Valiant Dancer
2002-Apr-10, 11:34 AM
On 2002-04-07 21:52, Jigsaw wrote:
There are a couple of scenes where she's in orbit in her ship, in zero G, and her hair, which is done in a smooth chin-length pageboy, is still a smooth chin-length pageboy. Shouldn't it be out around her head, given that it's zero gee?

Like this?
http://www.nasaexplores.com/lessons/01-044/images/bad_hair.jpg

Also, there's a short 1-second bit where the Evil General, also in orbit in zero G in a space station (I don't want to get into any spoilers here), pulls two big levers down at the same time, with both hands, like *ka-chunk*, and my son says that he should have been kicked backwards and upwards by the reaction. They're these two humongous levers, and he's kind of bending over a little bit (stooping over) to pull them both down from about shoulder height towards his waist-level, so The Kid says that he should have had his legs kicked out from under him, backwards, and upwards backwards (is this making sense?)




About the hair. One word. Mousse. Lots of it.

About the levers, if he didn't have straps in the floor to hold his boots down or magnetic boots, your son is very astute. The Evil General would indeed be doing the mid-air cartwheel thing. And the levers would remain unpulled.

Donnie B.
2002-Apr-10, 04:32 PM
On 2002-04-10 07:34, Valiant Dancer wrote:
About the levers, if he didn't have straps in the floor to hold his boots down or magnetic boots, your son is very astute. The Evil General would indeed be doing the mid-air cartwheel thing. And the levers would remain unpulled.

That also depends on the stiffness of the action of the levers. If they're "light" enough, the inertia of his body mass would provide enough "ground" to pull the levers down. Er, if "down" is the right word, under the circumstances...

Valiant Dancer
2002-Apr-10, 06:47 PM
On 2002-04-10 12:32, Donnie B. wrote:


On 2002-04-10 07:34, Valiant Dancer wrote:
About the levers, if he didn't have straps in the floor to hold his boots down or magnetic boots, your son is very astute. The Evil General would indeed be doing the mid-air cartwheel thing. And the levers would remain unpulled.

That also depends on the stiffness of the action of the levers. If they're "light" enough, the inertia of his body mass would provide enough "ground" to pull the levers down. Er, if "down" is the right word, under the circumstances...



The description of how the Evil General pulls the levers tends to indicate stiff action. Therefore, needing grounding for proper activation. (Although why he didn't just flip upside-down so he would be pusing the levers up is beyond me. It would not require funky physics.

Jigsaw
2002-Apr-11, 12:43 AM
Well, they couldn't have had him flip upside-down in order to push the levers and make the laws of zero-Gee physics happy, because the script called for him to say something evil and gloating (I don't remember exactly what it was), just before he pulled them, and it's difficult to look like an Evil Gloating Monomaniac if you're hanging upside-down like a goofy shuttle astronaut... /phpBB/images/smiles/icon_biggrin.gif

Conrad
2002-Apr-11, 08:09 AM
Hey, Jigsaw, I saw the film, and got the DVD - and it's over 20 years since anyone called me a teenager.

As for that "It's just a cartoon", well, look what happened to Lara Croft (yes, yes, I know, lots of Bad Astronomy)

Could Aki's hair be a one-piece wig Velcro'd to her head? That way she could take it off when her head got too hot. Don't laugh, check out the TV series "UFO" and the purple wigs worn by female staff in that.

Donnie B.
2002-Apr-11, 09:24 AM
Those were wigs? /phpBB/images/smiles/icon_biggrin.gif

Conrad
2002-Apr-11, 10:27 AM
"Those were wigs?"

asked Donnie B.
(Sorry, haven't figured how to cut & paste more than that)

Oh yes they were. In later years, anoraks - sorry, Intense Fans - pondered exactly why women might wear such strange things. The best suggestion was that they were anti-migraine static-dispersing wigs.

None of which has anything to do with astronomy, so in "UFO", how exactly did SHADO manage to set up an enormous Moonbase in total secrecy? Don't forget, it was so large that telescopes on Earth would have been able to see it.
/phpBB/images/smiles/icon_wink.gif

GrapesOfWrath
2002-Apr-11, 10:46 AM
On 2002-04-11 06:27, Conrad wrote:
(Sorry, haven't figured how to cut & paste more than that)

Use the Quote button at the bottom of the post to which you are replying. It uses BBcode (http://www.badastronomy.com/phpBB/faq.php#bbcode) to set off quoted material.

Conrad
2002-Apr-11, 01:35 PM
On 2002-04-11 06:46, GrapesOfWrath wrote:


On 2002-04-11 06:27, Conrad wrote:
(Sorry, haven't figured how to cut & paste more than that)

Use the Quote button at the bottom of the post to which you are replying. It uses BBcode (http://www.badastronomy.com/phpBB/faq.php#bbcode) to set off quoted material.


Boffo!
Thanks very Much, Mr - er, Grapes?
Nothing will constrain me now!

ToSeek
2002-Apr-11, 01:38 PM
On 2002-04-11 06:27, Conrad wrote:
None of which has anything to do with astronomy, so in "UFO", how exactly did SHADO manage to set up an enormous Moonbase in total secrecy? Don't forget, it was so large that telescopes on Earth would have been able to see it.
/phpBB/images/smiles/icon_wink.gif


It must have been on the dark side of the Moon. /phpBB/images/smiles/icon_wink.gif

Mr. X
2002-Apr-12, 12:30 AM
Velcro? Shado? Wigs? Mousse?

Textured-mapped polygons and low poly-count is more like it... I told you already.

lpetrich might be more qualified for an accurate description, since I'm just a student.

lpetrich
2002-Apr-12, 02:38 AM
To get a completely-realistic simulation of hair means following the physics of 100,000 strands, the average number on a human head. So the producers of the Final Fantasy movie had taken some big shortcuts somewhere. Including making it seem as if Ms. Ross was using hairspray.

As to how the models were done, a likely way was to turn all the curved surfaces into collections of polygons and then render all those sets of polygons. The curved surfaces are likely specified as weighted averages of the positions of sets of control points, with the weighting being some quadratic or cubic function of a position parameter (two parameters in the case of surfaces).

The flat-surface vertices and curved-surface control points were then likely controlled with bones, which are points combined with rotations and shifts. Which are applied to the difference of a controlled point's position and the bone point's position. Furthermore, bone effects can be blended; a point can be controlled by more than one bone.

The actual rendering can be done by tracing a ray from a pixel position into the scene, and seeing where it hits. Ray-tracing is, however, computationally expensive, though various tricks can be used to work out what objects are likely to be nearby.

A computationally cheaper way of rendering is to raytrace to each polygon's vertices, ignoring anything in between and then paint that polygon in quasi-2D fashion, though with being careful to handle perspective (implicit raytracing). This requires that the polygons either be in back-to-front order or that they be rendered with a z-buffer. The z-buffer stores the depth of the last-rendered pixel; closer pixels are accepted and farther ones rejected.

Z-buffering does not quite make depth sorting obsolete; semitransparent pixels are not handled correctly, and polygons with them must still be depth-sorted.

Furthermore, when doing such direct rendering, it's helpful to do visibility calculations, to work out which objects are completely hidden, and thus not worth the effort of trying to render. Except in the trivial case of making a polygon one-sided, that's a complicated and hairy business.

I note that the makers of the FF movie had a big render farm of computers on hand, and plenty of time for rendering each frame, which is why the FF movie looks very fancy in comparison with even recent real-time-3D computer games, which are constrained by their much more limited computer horsepower.

lpetrich
2002-Apr-12, 04:07 AM
First, I'd like to point out that one computer game does do animated hair reasonably correctly, and that is the Tomb Raider series with Lara Croft's ponytail.

But one can easily cheat with a ponytail; in the game, it is modeled as a series of segments.

The history of real-time-3D computer games is an interesting story of technological evolution, including a long history of shortcuts and kludges designed for getting reasonable performance on the available hardware. Though the story of that evolution is probably off-topic.

Their ancestors are real-time-2D games, with the background and the foreground entities all being constant-size 2D artwork, or sprites.

The first real-time-3D game I know of was Atari's Battlezone from 1980; one drives a tank and tries to destroy enemy tanks. It had wireframe graphics -- which required a co-processor to do the perspective calculations for the line ends -- a division per vertex.

Fast forward to the early 1990's, when texture-mapped RT3D games started becoming feasible. The earlier ones still used sprites for their characters, but were able to render them in different sizes, but 3D models started appearing in the mid-1990's. However, these are all flat-polygon models, because that's what's easiest to render; many of the earlier ones tended to be rather blocky. However, good surface-texture (skin) painting and lighting effects can often hide much of the blockiness.

The world geometries were first only horizontal and vertical surfaces, because these could be rendered with the least setup cost (only one perspective calculation per scanline); as CPU power increased, world geometries started getting lots of intermediate slopes.

One recent trend has been 3D-accelerator video cards; they take a big load off of the CPU: the rasterization or painting step. This has the additional benefit of allowing textures to look smooth instead of pixelated, as is necessary with pure-CPU rendering in order to get reasonable performance.

Jigsaw
2002-Apr-13, 12:40 AM
Just out of curiosity, how much longer until they DO have the technology to animate 100,000 strands of human hair? I'm assuming that there's some kind of realistic estimate that can be made...

I can remember when George Lucas (or whoever it was--maybe it was Spielberg) was predicting a few years back that "someday we'll have entire movies made with nothing but CGI humans, no real humans at all, and the CGI humans will be so good that you won't be able to tell they aren't real", and that was when the first Toy Story had just come out and all the humans in it looked so *plastic*, and everybody went, "Yeah, right, George." (or Steve)

And so fast forward X number of years, to last week, when I was walking past the TV when The Kid was watching this flick the first time around (by himself), and I saw that it had real people in it, and I said, "Hey, I thought the whole idea was that these were CGI characters," and he said, "Mom, those ARE CGI characters," and I went, "Wow." You can see pores and everything. And you can see his TRICEPS flex, when he pushes himself up...

So what are we looking at, for the sequel to have realistic zero-gee hair? Two years? Five years?

Mr. X
2002-Apr-13, 01:14 PM
First, I'd like to point out that one computer game does do animated hair reasonably correctly, and that is the Tomb Raider series with Lara Croft's ponytail.


I'd tend to disagree with Lara's hair... it's not that nice. An excellent example of an object that behaves somewhat like hair is the tie (yep, tie, you know the thingy you wear?) of the Hitman (or 47 however you wish to call the unnamed character) from Hitman: Codename 47. Lara's ponytail had problems with clipping, at least in the second one, and it was (as you said) segments, whereas the tie of the Hitman is entirely smooth. By the way the physics of Hitman are otherwise unbelievable. However the game bogs down to an utterly unplayable mess after "hitting" around 75-100 people, I don't really know why.

A good example of good looking characters that are low-poly count but very high-res textured is Max Payne. The characters get an incredibly real feel in spite of their polygon count or that the movement of the clothes is "pre-animated".

Doom 3's engine (so far) could look like Final Fantasy on the computer and in Real-time. We'll have to see I guess.

GrapesOfWrath
2002-Apr-13, 08:07 PM
On 2002-04-11 09:35, Conrad wrote:
Thanks very Much, Mr - er, Grapes?


Mr. Wrath, but call me Grapes, everyone else does. Just don't call me Grapes-O, unless you wanna mix it up. Then, I'm there.

Hair animation is tricky. Remember the hair on the skin of the hobbits in Bakshi's animated version of the Lord of the Rings? It looked...alive. And that wasn't a good thing.

Conrad
2002-Apr-14, 09:13 PM
Actually I remember a quote from a computer animator at the time of "Toy Story", to the effect that things like HAIR, smoke and fire were very difficult to do as CGI effects. (ah, what the heck, I still remember my first computer, a Spectrum 128+2!).
As a science dilettante (yes, a peculiar creature!), my view is that the people who work at the cutting edge of this field use their imagination first, and only then begin to think if the hardware can keep up. In the same way as architects, I think.

ToSeek
2002-Apr-15, 11:20 AM
On 2002-04-14 17:13, Conrad wrote:
As a science dilettante (yes, a peculiar creature!), my view is that the people who work at the cutting edge of this field use their imagination first, and only then begin to think if the hardware can keep up.


I understand that's the main reason it took so long for this set of Star Wars movies to come out - George Lucase was waiting for the technology to catch up with what he had in mind.

Mr. X
2002-Apr-16, 01:16 AM
Imagination first? Well maybe, as the only limit in that field is your mental capacity to twist and turn logic around until you start bursting brain blood vessels. I'd tend to say that in that particular field things move faster than the thought that moves them. /phpBB/images/smiles/icon_razz.gif

And things catching up with what people had in mind? Hasn't it been the case with Stanley Kubrik's A.I.?

<font size=-1>[ This Message was edited by: Mr. X on 2002-04-15 21:18 ]</font>

DarthMooo
2002-May-05, 06:57 PM
Maybe she's using REEEEALY powerful hairgel.
/phpBB/images/smiles/icon_confused.gif /phpBB/images/smiles/icon_lol.gif /phpBB/images/smiles/icon_confused.gif

thkaufm
2002-Jun-16, 02:39 AM
CG hair is not actual modeled geometry. It is generated during rendering using a fewer number of modeled guides to control it's placement and movement.

There are several very good, off the shelf hair rendering programs available. Some studios also use their own in-house developed hair rendering technology.

The current state of art hair rendering solutions are able to produce very convincing cg hair.


Here are some examples.

http://www.joealter.com/shave/dynamics.htm
http://www.worley.com/sasquatch/sasquatch.html#top

Tom

ZaphodBeeblebrox
2002-Jun-16, 07:04 AM
On 2002-04-12 00:07, lpetrich wrote:
The history of real-time-3D computer games is an interesting story of technological evolution, including a long history of shortcuts and kludges designed for getting reasonable performance on the available hardware. Though the story of that evolution is probably off-topic.

Their ancestors are real-time-2D games, with the background and the foreground entities all being constant-size 2D artwork, or sprites.


Yeah, do you Remember Mario, of Donkey Kong Fame?

He had a Hat, because they had a very Hard Time, with Hair, and he had a Mustache, because they Couldn't do a Mouth, at All!

thkaufm
2002-Jun-18, 04:02 AM
Just out of curiosity, how much longer until they DO have the technology to animate 100,000 strands of human hair?{/QUOTE]

The technology exists right now, only the collision is not calculated for every hair, just for the guide hairs. the renderer fills in the rest of the hairs at render time.It's not uncommon to render millions of hairs.

I guess if you really wanted to you could calculate every hair. It would take a long time though, and you probably wouldn't be able to notice the difference in most situations.

[quote]Toy Story had just come out and all the humans in it looked so *plastic*,

Some of that was the technology of the time, but some of it was intentional. Movies such as Toy Story and Shrek are not meant to be photoreal, so sometimes they have to dial back on the realism because it doesn't fit the style of the movie.

Tom