How to render realistic human faces?

[991060]

Hi all:
I'm currently working on a human face simulation project. The boss wants me to render very realistic human faces. Since the schedule is very tight, I decide to initiate a thread here, hoping some of you have related experience on the subject.
Generally, any kind of information is appreciated, but easy-to-implement methods come with priority since I don't have much time before the deadline.
Thank you all again.

 

[assen]

First, you need good modelling as a start. You should probably check some of the modellers' specialized forums and ask there. Maybe even subcontract somebody.

As for the actual rendering - I'm assuming you mean realtime, using e.g. DX9-class hardware - there were several good papers recently. Google for things like "subsurface scattering", "human skin modelling", "translucent", "blood vessels".

There was a couple of neat paper from ATI about hair and skin - namely, the hair of Ruby, and the skin of bad-guy-with-huge-diamond-wossname. They should be good starting points, from there look in their bibliographies.

 

[[maven]]

Paul Debevec (sp?) did light-probes of faces and they look quite nice. Have a look at his papers.

 

[Wunderchu]

Hi all:
I'm currently working on a human face simulation project. The boss wants me to render very realistic human faces. Since the schedule is very tight, I decide to initiate a thread here, hoping some of you have related experience on the subject.
Generally, any kind of information is appreciated, but easy-to-implement methods come with priority since I don't have much time before the deadline.
Thank you all again.

perhaps ask someone here:

http://www.cgtalk.com

 

[jpeter]

http://graphics.ucsd.edu/~henrik/papers/face_cloning/

may help you

 

[KimB]

Here's an nVidia paper on translucency that gives a nice overview of what can be done with realtime hardware, with links to some more in-depth stuff.

http://developer.nvidia.com/object/real_time_translucency_gdc2004.html

 

[Jodi]

Don't forget the eyes!

Doom3 looked really pretty, except the eyes looked dead.

Eyes have a film of water over them, so are shiney, they also are not a pure sphere (lens bulge), and don't forget the iris detail, and blood vessles in the eye.

And all this, just for the eye!

 

[KimB]

Doom3 looked really pretty, except the eyes looked dead.

Apparently this is because the specular function that is used in Doom 3 is global and is approximately that of a dull plastic. Later uses of the game engine that drop support for pre-DX9 cards should improve specular quality dramatically.

 

[991060]

Thanks dudes, some of the methods you mentioned looks too complex to me, I only have very limited time and resources on the project, don't know how much I can put in the program. Anyway, thanks for the info.

 

[Goragoth]

I only have very limited time and resources on the project, don't know how much I can put in the program

Rendering realistic faces is not really a simple topic, in fact its probably the single hardest problem in redering that exists today. Of course I can see what you are saying, you want the best possible within the constraints that you have to work with, best of luck with that

As far as rendering techniques go subsurface scattering is definatively the biggy you will want to look at and implement if you have the time, other than that there's not a huge amount you can do from a programming perspective when you are working realtime, I would say most of the work is really up to the artist doing the modelling. Note that when I say there isn't much you can do I mean stuff that's specific to faces, of course implementing normal mapping, per pixel lighting and optimizing for high poly counts/texture sizes, etc all helps

human face simulation project

I assume that this means that there will also be animation going on? If so you probably want to use morphs/blend shapes for the facial animation. Sorry if I'm being Captain Obvious or completely shooting past the mark since I don't really know what you have done so far or exactly what it is you want to do. Might be helpful if you went into some more detail (obviously only if you can without violating any NDAs). My main question would be how you are going to get the models (and animations if you will have them), i.e. are you going to make them, do you already have somebody who will make them or are you going to outsource the work or are you working with pre-existing models/animations?

 

[991060]

Thanks Goragoth, I'll be more specific this time.
What I'm doing now is a demonstration of human head based on skeleton animation system. It has a lip-sync system which enables it to animate according the users' input. Now the animation and lipsync system is nearly done, and I can say the effect is quite good, considering the very little time I've spent on it.(I can send a copy to anyone interested, but it only supports Chinese now )
Now the problem is that the model lacks good lighting effect, I only used multi-texturing for now. I have an artist do the art work, and I'm responsible for the shader stuff. My boss wants the demo for a private presentation about 10 days later, hence I need sth cool and EASY to implement so that I won't screw the schedule. I've done some google work, finding a lot of pdfs describing many cool techniques which are simply too complex for a 10 days' schedule. Yeah, I know rendering realistic human faces is quite hard, it's not like rendering metal or glass or other stuff for which you just use some per-pixel lightings and the boss is happy. I'll read those ATi papers now, hope I can find an easy way to achieve similar effect, wish me luck. 8)

 

[KimB]

Well, I think you should be able to do a tranlucency effect for the skin, and a shiny effect for the eyes pretty quickly.

 

[PC-Engine]

Skin elasticity and facial muscle movement.

 

[no_way]

Thanks Goragoth, I'll be more specific this time.
What I'm doing now is a demonstration of human head based on skeleton animation system.

If you are doing animation and looking for realism, definitely check out Perlins procedural animation too
http://mrl.nyu.edu/~perlin/experiments/facedemo/
http://www.google.com/search?&q=perlin+animation+noise