Paul Debevec animates a photo-real digital face

86,234 views ・ 2009-10-20

TED


请双击下面的英文字幕来播放视频。

翻译人员: Yin`ai Sun 校对人员: Halei Liu
00:18
One of the biggest challenges in computer graphics
0
18330
3000
计算机图形制作面临的巨大挑战之一
00:21
has been being able to create a photo-real,
1
21330
2000
是如何制作一个真实的
00:23
digital human face.
2
23330
2000
人物面部表情。
00:25
And one of the reasons it is so difficult is that, unlike aliens and dinosaurs,
3
25330
3000
不像外星人和恐龙,它之所以如此困难的原因是
00:28
we look at human faces every day.
4
28330
3000
我们每天都会看到人的面部表情
00:31
They are very important to how we communicate with each other.
5
31330
2000
面部表情对我们非常重要,因为我们通过表情来彼此沟通
00:33
As a result, we're tuned in to the subtlest things
6
33330
3000
由此可见我们会注意那些非常微妙的东西
00:36
that could possibly be wrong with a computer rendering,
7
36330
2000
通过计算机直接渲染出来的很可能是不正确的
00:38
in order to believe whether these things are realistic.
8
38330
3000
更无法使人相信这些是真实的
00:41
And what I'm going to do in the next five minutes
9
41330
2000
在接下来的5分钟里面
00:43
is take you through a process
10
43330
2000
我将带领大家一起浏览一个流程
00:45
where we tried to create a reasonably photo-realistic computer-generated face,
11
45330
3000
来通过计算机创造一个写实的人物表情
00:48
using some computer graphics technology we've developed,
12
48330
3000
通过我们开发的一系列计算机图形技术
00:51
and also some collaborators at a company called Image Metrics.
13
51330
2000
同时和一些来自Image Metrics公司的伙伴
00:53
And we're going to try to do a photo-real face
14
53330
2000
我们将尝试制作一个写实的
00:55
of an actress named Emily O'Brien, who is right there.
15
55330
3000
名叫艾米丽(Emily O'Brien)的女演员的表情,她就在那儿。
00:58
And that's actually a completely computer-generated rendering of her face.
16
58330
3000
那实际上是一个完全由计算机渲染生成的她的面部头像。
01:01
By the end of the talk, we're going to see it move.
17
61330
2000
在讲座的结尾,我们将看到她动起来
01:03
The way that we did this is we tried to start with Emily herself,
18
63330
3000
我们尝试的方式是通过Emily她自己
01:06
who was gracious enough to come to our laboratory
19
66330
3000
她非常优雅高尚地进入我们的实验室
01:09
in Marina Del Rey, and sit for a session in Light Stage 5.
20
69330
3000
在玛丽安德尔湾,并坐到了我们的设备灯光舞台5当中
01:12
This is a face-scanning sphere, with 156 white LEDs all around
21
72330
4000
这是一个面部扫描球体,有156个白色的发光二极管分部在其中,
01:16
that allow us to photograph her
22
76330
2000
配合我们对她进行拍照
01:18
in a series of very controlled illumination conditions.
23
78330
3000
通过一系列严格控制的光照条件
01:21
And the lighting that we use these days looks something like this.
24
81330
3000
我们近期使用的光照方式看起来是这样的。
01:24
We shoot all of these photographs in about three seconds.
25
84330
2000
我们在三秒钟之内拍摄出全部这些照片。
01:26
And we basically capture enough information
26
86330
3000
我们主要地会采集足量的信息
01:29
with video projector patterns that drape over the contours of her face,
27
89330
4000
通过图像投影模拟出她的面部轮廓
01:33
and different principle directions of light from the light stage,
28
93330
2000
以及通过灯光舞台得到的不同角度光照条件下的数据
01:35
to figure out both the coarse-scale
29
95330
2000
来计算出粗略的骨骼模型
01:37
and the fine-scale detail of her face.
30
97330
2000
以及她的精细的面部细节模型数据
01:39
If we zoom in on this photograph right here,
31
99330
2000
如果我们看放大的这张照片
01:41
we can see it's a really nice photograph to have of her,
32
101330
2000
我们可以很清晰地看到她的面部细节
01:43
because she is lit from absolutely everywhere at the same time
33
103330
4000
因为她的面部被同时从每个角度完全地照亮了
01:47
to get a nice image of her facial texture.
34
107330
2000
来得到一份非常高质量的她的面部表情贴图
01:49
And in addition, we've actually used polarizers on all the lights --
35
109330
3000
并且,我们实际上在所有灯上面应用了偏振镜
01:52
just like polarized sunglasses can block
36
112330
2000
就如同偏振的太阳镜可以阻挡
01:54
the glare off of the road,
37
114330
2000
马路上的耀眼光斑
01:56
polarizers can block the shine off of the skin,
38
116330
2000
偏振镜可以组织皮肤上出现光芒
01:58
so we don't get all those specular reflections to take this map.
39
118330
3000
所以我们没有采集到这些贴图的高光反射部分
02:01
Now, if we turn the polarizers around just a little bit,
40
121330
2000
现在,如果我们稍微调整一下偏振镜
02:03
we can actually bring that specular reflection
41
123330
2000
我们就可以得到高光的反射
02:05
of the skin back in,
42
125330
2000
在皮肤上面
02:07
and you can see she looks kind of shiny and oily at this point.
43
127330
3000
并且,你会看到她的面部看起来有些闪耀和油光。
02:10
If you take the difference between these two images here,
44
130330
3000
如果你取一下两张图像的差
02:13
you can get an image lit from the entire sphere of light
45
133330
2000
你得到的合成图像就是360度的光照条件下
02:15
of just the shine off of Emily's skin.
46
135330
3000
艾米丽(Emily)皮肤的光照效果
02:18
I don't think any photograph like this had ever been taken
47
138330
2000
我认为没有任何图像会这样拍摄
02:20
before we had done this.
48
140330
2000
在我们这样做之前。
02:22
And this is very important light to capture,
49
142330
3000
采集光照信息是非常重要的,
02:25
because this is the light that reflects off the first surface of the skin.
50
145330
2000
因为光照会反射出皮肤表面的最上一层
02:27
It doesn't get underneath the translucent
51
147330
2000
它不会出现在下层半透明层,
02:29
layers of the skin and blur out.
52
149330
2000
它会模糊掉。
02:31
And, as a result, it's a very good cue
53
151330
2000
由此可见,它是一个很好的线索
02:33
to the detailed shape of the skin-pore structure
54
153330
3000
来获得皮肤细致的毛孔结构
02:36
and all of the fine wrinkles that all of us have,
55
156330
2000
以及我们都有的皮肤褶皱细节的全部,
02:38
the things that actually make us look like real humans.
56
158330
2000
实际上,这些都使得它看起来更接近人类的真实效果。
02:40
So, if we use information that comes off of this specular reflection,
57
160330
4000
如果,我们使用来自高光反射的信息
02:44
we can go from a traditional face scan
58
164330
2000
我们可以通过传统的面部扫描而
02:46
that might have the gross contours of the face and the basic shape,
59
166330
4000
得到面部的粗略的轮廓和基本的形状,
02:50
and augment it with information
60
170330
2000
同时输入大量的信息
02:52
that puts in all of that skin pore structure and fine wrinkles.
61
172330
3000
皮肤的毛孔结构和纹理特征
02:55
And, even more importantly,
62
175330
2000
更重要的是,
02:57
since this is a photometric process that only takes three seconds to capture,
63
177330
3000
因为这是基于照片建模的流程而我们只采集了3秒钟的照片数据
03:00
we can shoot Emily
64
180330
2000
我们可以用一下午的时间
03:02
in just part of an afternoon,
65
182330
2000
拍艾米丽(Emily),
03:04
in many different facial poses and facial expressions.
66
184330
3000
拍摄不同的面部姿态和表情变化。
03:07
So, here you can see her moving her eyes around, moving her mouth around.
67
187330
3000
这里,你可以看到她转动眼睛,嘴巴的开合。
03:10
And these we're actually going to use to create a photo-real digital character.
68
190330
3000
这些,实际上都会被我们用来创造数字虚拟的写实人物。
03:13
If you take a look at these scans that we have of Emily,
69
193330
4000
来看一下这些我们对艾米丽(Emily)进行的扫描
03:17
you can see that the human face does an enormous amount of amazing things
70
197330
3000
你会看到我们人类面部表情是千变万化的
03:20
as it goes into different facial expressions.
71
200330
3000
在不同的面部表情变换之中
03:23
You can see things. Not only the face shape changes,
72
203330
3000
你会看到,不仅仅是面部形态发生变化
03:26
but all sorts of different skin buckling and skin wrinkling occurs.
73
206330
4000
以及各种各样的皮肤的弧线和皮肤上的褶皱出现。
03:30
You can see that the skin pore structure changes enormously
74
210330
4000
你可以看到皮肤毛孔结构也有着巨大的变化
03:34
from stretched skin pores
75
214330
2000
从被拉伸的皮肤毛孔,
03:36
to the regular skin texture.
76
216330
2000
到普通的皮肤质地
03:38
You can see the furrows in the brow and how the microstructure changes there.
77
218330
3000
你可以看到前额眉骨那里细微的变化。
03:41
You can see muscles pulling down at flesh to bring her eyebrows down.
78
221330
4000
你可以看到肌肉的收缩在她皱眉的时候。
03:45
Her muscles bulging in her forehead when she winces like that.
79
225330
3000
她前额的肌肉会这样的膨胀,在她畏惧的时候。
03:48
In addition to this kind of high-resolution geometry,
80
228330
3000
对于这样高分辨率的几何体,
03:51
since it's all captured with cameras, we've got a great texture map to use for the face.
81
231330
4000
因为这些都通过照相机采集,我们有足够的她的面部表情贴图。
03:55
And by looking at how the different color channels of the illumination,
82
235330
2000
通过颜色和亮度不同的通道,
03:57
the red and the green and the blue,
83
237330
2000
红绿蓝色彩通道
03:59
diffuse the light differently,
84
239330
2000
受光照不同的漫反射
04:01
we can come up with a way of shading the skin on the computer.
85
241330
3000
我们可以通过计算机总结出为皮肤添加阴影的方式。
04:04
Then, instead of looking like a plaster mannequin,
86
244330
3000
那么,不同于看起来如同石膏像的假人,
04:07
it actually looks like it's made out of living human flesh.
87
247330
3000
她看起来如同人类一样鲜活。
04:10
And this is what we used
88
250330
2000
这就是我们使用的
04:12
to give to the company Image Metrics
89
252330
2000
为Image Metrics公司
04:14
to create a rigged, digital version of Emily.
90
254330
3000
制作的写实的数字虚拟人物Emily。
04:17
We're just seeing the coarse-scale geometry here.
91
257330
2000
这里,我们看看一下粗糙的几何模型
04:19
But they basically created a digital puppet of her,
92
259330
3000
但他们已经对她创建了一些基本的数据程式,
04:22
where you can pull on these various strings,
93
262330
2000
你可以拖拽这些不同的坐标,
04:24
and it actually moves her face in ways that are
94
264330
2000
它实际上运动的方式就会依照
04:26
completely consistent with the scans that we took.
95
266330
2000
我们扫描出的数据那样。
04:28
And, in addition to the coarse-scale geometry,
96
268330
2000
并且,对于这个基本模型,
04:30
they also used all of that detail
97
270330
2000
他们也使用了全部的细节
04:32
to create a set of what are called "displacement maps"
98
272330
3000
来创建一些列的置换贴图
04:35
that animate as well.
99
275330
3000
同样可以对其进行动画设置。
04:38
These are the displacement maps here.
100
278330
2000
这里是一些置换贴图
04:40
And you can see those different wrinkles actually show up as she animates.
101
280330
3000
同时你可以看到不同的褶皱出现在她的动画之中。
04:43
So the next process was then to animate her.
102
283330
2000
所以,接下来的步骤是对她进行动画设置。
04:45
We actually used one of her own performances to provide the source data.
103
285330
4000
我们实际上应用她自身的表演作为源数据。
04:49
So, by analyzing this video with computer vision techniques,
104
289330
3000
通过计算机视觉技术来分析这些视频,
04:52
they were able to drive the facial rig
105
292330
2000
他们可以驱动表情的变化
04:54
with the computer-generated performance.
106
294330
2000
通过计算机的预置效果生成。
04:56
So what you're going to see now, after this,
107
296330
2000
所以,我们将看到,通过这一切处理,
04:58
is a completely photo-real digital face.
108
298330
2000
是一个完全写实的数字话面部。
05:00
We can turn the volume up a little bit if that's available.
109
300330
2000
我们可以开大一点声音,如果可以的话。
05:02
Emily: Image Metrics is a markerless, performance-driven animation company.
110
302330
4000
Emily:Image Metrics是一家追求高效的动画公司
05:06
We specialize in high-quality facial animation
111
306330
3000
我们致力于制作高质量的面部表情动画
05:09
for video games and films.
112
309330
2000
为视频游戏和电影。
05:11
Image Metrics is a markerless, performance-driven animation company.
113
311330
4000
Image Metrics是一家追求高效动画的公司。
05:15
We specialize in high quality facial animation
114
315330
3000
我们致力于制作高质量的面部表情动画
05:18
for video games and films.
115
318330
3000
为视频游戏和电影。
05:21
Paul Debevec: So, if we break that down into layers, here's that diffuse component
116
321330
2000
保罗·德贝维奇:如果我们把它分解到各个层,这是漫反射部分
05:23
we saw in the first slide.
117
323330
2000
我们在第一张幻灯片里面看到的。
05:25
Here is the specular component animating.
118
325330
2000
这是高光部分的动画。
05:27
You can see all the wrinkles happening there.
119
327330
2000
你们可以看到各处皮肤褶皱的出现。
05:29
And there is the underlying wireframe mesh.
120
329330
5000
这是原始的线框结构层。
05:34
And that is Emily herself.
121
334330
2000
那是Emily她自己。
05:36
Now, where are we going with this here?
122
336330
2000
现在,我们接下来会做些什么?
05:38
We've gone a little bit beyond Light Stage 5. This is Light Stage 6,
123
338330
4000
我们已经有了高于灯光舞台5的装置设备。这是灯光舞台6.
05:42
and we're looking at taking this technology
124
342330
2000
我们期望将这一技术
05:44
and applying it to whole human bodies.
125
344330
2000
应用到人的全身。
05:46
This is Bruce Lawmen, one of our researchers in the group,
126
346330
2000
这是布鲁斯 劳曼,我们研发团队中的一位,
05:48
who graciously agreed to get captured running in the Light Stage.
127
348330
3000
非常乐意配合我们采集他在灯光舞台中跑步的数据。
05:51
And let's take a look at a computer-generated version
128
351330
2000
下面让我们看一下计算机生成的
05:53
of Bruce, running in a new environment.
129
353330
2000
布鲁斯的影像,在一个全新的环境中跑步。
06:01
And thank you very much.
130
361330
2000
非常感谢。
06:03
(Applause)
131
363330
1000
(掌声)
关于本网站

这个网站将向你介绍对学习英语有用的YouTube视频。你将看到来自世界各地的一流教师教授的英语课程。双击每个视频页面上显示的英文字幕,即可从那里播放视频。字幕会随着视频的播放而同步滚动。如果你有任何意见或要求,请使用此联系表与我们联系。

https://forms.gle/WvT1wiN1qDtmnspy7