Why do some CG people look dead?

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

THREAD CLOSED
 
Thread Tools Search this Thread Display Modes
Old 05 May 2013   #31
>Why do some CG people look dead?

They work too many hours :P
 
Old 05 May 2013   #32
Originally Posted by NorthernDoubt: >Why do some CG people look dead?

They work too many hours :P

Post of the month.
__________________
Come, Join the Cult http://www.cultofrig.com - Rigging from First Principles
 
Old 05 May 2013   #33
Originally Posted by CGIPadawan: It's the Eyes.


You could be right. Any of my college friends studying CG say the big deal now is getting realism in the eyes and the immediate area around them.
__________________
I like to learn.
 
Old 05 May 2013   #34
Eyes are tough. Convincing deformation in the face its pretty darn hard too.
I find hyper-real stills 'interesting'. But hyper-real animated is very difficult
not to look 'uncanny'.
I also tend to 'buy it' more when its not exactly human.
Golem and Davy Jones were an easier sell to my eyes than Benjamin Button
which sometimes fell-over for me in certain shots even though I can hugely appreciate the work involved.
 
Old 05 May 2013   #35
They gave a great lecture on eyes at a big studio I worked at a few years back. They said that they were dissappointed with how some of their cg humanoid characters turned out in their latest big blockbuster. They had done extensive research and testing of modeling, texturing, animation, and lighting to make sure they looked realistic but they fell apart when rendered for the big screen. Afterwards they realized that the whole way cg eyes are traditionally textured, modeled and lit is wrong. They showed an example of the cg characters in playblast form and their eyes were looking exactly into the eyes of the real-life actor. They then showed the same shot lit and rendered and the eyelines no longer matched at all. Its something about the way the light bounces and refracts around in the cg cornea that makes the rendered eyelines look totally different than how they were animated. At the time they were trying to figure out if there was a way to animate them differently to compensate or write a shader that would more actually reflect the intended eyeline. I don't know if they ever completely figured it out.
__________________
"Have you ever just stared at it.......Marveled at its bee yooty?"
 
Old 05 May 2013   #36
Originally Posted by Dillster: You could be right. Any of my college friends studying CG say the big deal now is getting realism in the eyes and the immediate area around them.


A friend of mine who worked on both AVATAR and The Adventures of Tintin, and some of our own experience, leads me to say that's actually a misconception.

You don't go for Realism... you go for "Realism" (note double quotes).

It's about what people see in photos or images of REAL people... and you try and nail that instead of going after some kind of Biology lesson.

Worked a treat for them.. especially on AVATAR.

P.S.: Issue mentioned by Zac above also happened on our film. It's true... the light and shadows in rendering really appear to change the orientation and geometry of characters and eyelines... It's something you always have to look out for.

Align that with Leigh's earlier advice that final image is all that counts and you already know there is (probably) NEVER going to be a "blanket solution".
__________________
"Your most creative work is pre-production, once the film is in production, demands on time force you to produce rather than create."
My ArtStation

Last edited by CGIPadawan : 05 May 2013 at 12:39 AM.
 
Old 05 May 2013   #37
Eyes have all sorts of micro refractive light going on.

All eyes are pigmented dark brown. The only reason they're colored different is because of micro refractive light scattering within the iris.



Maybe it's off topic, but the vision researchers I work with have done a lot of studies with eye tracking to understand what people actually look at when presented with different images or video. They've also put a lot of time into understanding the science behind magic tricks with why people automatically focus on certain motions and ignore others.

Part of what's been discovered is how vision neurons fire when they focus. It's like an unsharp mask. To strengthen the signal of a single neuron, the surrounding neuron signals are simultaneously suppressed. This creates a blur within the brain's perception even though all the eye's receptors are still picking up sharp input signals.

This impacts how we think we see color as well.
 
Old 05 May 2013   #38
Originally Posted by sentry66: Eyes have all sorts of micro refractive light going on.

All eyes are pigmented dark brown. The only reason they're colored different is because of micro refractive light scattering within the iris.



Maybe it's off topic, but the vision researchers I work with have done a lot of studies with eye tracking to understand what people actually look at when presented with different images or video. They've also put a lot of time into understanding the science behind magic tricks with why people automatically focus on certain motions and ignore others.

Part of what's been discovered is how vision neurons fire when they focus. It's like an unsharp mask. To strengthen the signal of a single neuron, the surrounding neuron signals are simultaneously suppressed. This creates a blur within the brain's perception even though all the eye's receptors are still picking up sharp input signals.

This impacts how we think we see color as well.


Yes you can study all that...

Or you can just do step-render testing for yourselves... and then later have someone sit down and "cold watch" rendered footage. I find this approach easier than trying to look for white papers on "Micro-Refractions".
__________________
"Your most creative work is pre-production, once the film is in production, demands on time force you to produce rather than create."
My ArtStation
 
Old 05 May 2013   #39
It's ok, there is no such thing as micro refractions in first place (as it's always at a discrete unit photonic scale anyway), and it's incorrect to say it's due to refractive scattering as it's actually Rayleigh scattering, which is not refraction dependent, but rather polarization dependent, and generates refraction afterwards.

The irony of it is that, because it's a Rayleigh Phenomena, it's absolutely unnecessary to simulate it the way physics would have it. It's a colour change based on the polarization of a susceptible particle changing wavelength and therefore perceived colour.

In layman terms, simulating the complex model would be utterly pointless, as it would produce no different result whatsoever than colouring things directly the way a particle would when affected at that point (IE: painting a bloody texture and emitting some minor energy from it).

Unless we're now proposing we need to simulate in a forward fashion the molecular level wavelength of something to produce believable results, which would be, frankly speaking, absolutely ridiculous.

A model simplified through the elimination of reciprocal parts, and/or by replacing long parts of it that always produce the same pattern with a simplification, produces results, once sampled discretely, exactly as good as the full model would.

I think Lagrange proved this enough times over, and the discussion about such details, at least in the context of reproducing reality, is largely masturbation and e-peening.
Going into these details as if they mattered is akin to saying we should simulate at a galactic level to render a blue sky (Hi again, Mr Rayleigh), when painting or shading the right colours produces the same results with an added degree of control and at a vastly inferior cost.

The assumption we're just mucking around in the VFX industry, as if we didn't read the medical papers and get consultations from universities and professors at the top of their fields before spending mills on developing models, not to mention the large amount of competent physicists employed in various RnD departments, is also a bit offensive
__________________
Come, Join the Cult http://www.cultofrig.com - Rigging from First Principles

Last edited by ThE_JacO : 05 May 2013 at 11:15 AM.
 
Old 05 May 2013   #40
Originally Posted by ThE_JacO: It's ok, there is no such thing as micro refractions in first place (as it's always at a discrete unit photonic scale anyway), and it's incorrect to say it's due to refractive scattering as it's actually Rayleigh scattering, which is not refraction dependent, but rather polarization dependent, and generates refraction afterwards.

The irony of it is that, because it's a Rayleigh Phenomena, it's absolutely unnecessary to simulate it the way physics would have it. It's a colour change based on the polarization of a susceptible particle changing wavelength and therefore perceived colour.

In layman terms, simulating the complex model would be utterly pointless, as it would produce no different result whatsoever than colouring things directly the way a particle would when affected at that point (IE: painting a bloody texture and emitting some minor energy from it).

Unless we're now proposing we need to simulate in a forward fashion the molecular level wavelength of something to produce believable results, which would be, frankly speaking, absolutely ridiculous.

A model simplified through the elimination of reciprocal parts, and/or by replacing long parts of it that always produce the same pattern with a simplification, produces results, once sampled discretely, exactly as good as the full model would.

I think Lagrange proved this enough times over, and the discussion about such details, at least in the context of reproducing reality, is largely masturbation and e-peening.
Going into these details as if they mattered is akin to saying we should simulate at a galactic level to render a blue sky (Hi again, Mr Rayleigh), when painting or shading the right colours produces the same results with an added degree of control and at a vastly inferior cost.


I know Rayleigh scattering is tiny, but isn't that exactly what modern skin shaders are now attempting to simulate because that's how skin's perceived color actually works? Take MR's SSS2 shader and existing vray sss shaders for instance. I've seen people incorrectly call it "color bleed".

And just like like tiny photons in real life, even though the light wavelength differences are small, when they happen everywhere across a surface, they add up they turn into something we actually do see on a macro level - hence things like seeing a blurry red color bleed around the corner of the nose or how skin in general having a blue "diffuse" color where light hits.


Take that eye close up shot posted earlier for instance:
http://www.youtube.com/watch?v=16HD0QHCT9g

If you watch it in HD, you can see as plain as day that most of the skin on the very left is starting to tint blue, then the skin above and below the eye is tinted green/yellow, while the eye lid is tinted blue where it's bright, but is red where it's darker since the light is coming from the left has to travel through the skin to that area.

If you pay special attention to the skin in the lower right of the screen, you'll notice that each skin bulge isn't simply blue or pink, it's both depending on where the light hits when it moves. It's a dynamic property. Less photons hit each skin bulge than the entire face and thus the light hitting the bulges travels less than the total light across the whole face.

Now if you took a normal SSS shader, you'd probably set the SSS radius to work on a macro scale for the whole face, but not those individual skin bumps. For this shot though, you'd ideally need both because you're able to see those skin bulges fairly well. For most shots, painting them a static color is probably good enough if there's not a lot of subtle movement. The more the skin wrinkles and stretches though, the more you'll need to see the effect of smaller scale rayleigh scattering.

The problem with modern skin shaders is they all assume light intensity is the same for both macro and micro details and therefore assume light scatters the same amount for both which is incorrect.


Originally Posted by ThE_JacO: The assumption we're just mucking around in the VFX industry, as if we didn't read the medical papers and get consultations from universities and professors at the top of their fields before spending mills on developing models, not to mention the large amount of competent physicists employed in various RnD departments, is also a bit offensive


It's only offensive if you're taking it way too personal

Everything we simulate with a computer is a fake. It's a given Like you said, computers are not mini physical universes.

Anyone who can create a successful shot, is good at their job.
Creating good shots is what the the CG field ultimately is about right?







Originally Posted by CGIPadawan: Yes you can study all that...

Or you can just do step-render testing for yourselves... and then later have someone sit down and "cold watch" rendered footage. I find this approach easier than trying to look for white papers on "Micro-Refractions".


Of course it's easier, but at the same time we have to be willing to learn things in order to write new shaders and software

We take energy conserving shaders for granted now after a lot of research was made.

Anisotropy is an attribute that might drive someone mad if they didn't have it built into their shader. What other choice would they have other than setting up a really high res fine bump map or faking it with an image sequence of the highlight elongating and changing in sync with the camera?

We automatically dial in things like fresnel and refractive index settings because we've had to learn about them and saw a table of settings at some point (based on scientific measurements). We're not born knowing the refractive index for glycerol. I for one at least would have to look it up.

We can always observe things and just wing it until it looks good enough for our shots, but if we don't have a good and reliable method to represent it in CG, it won't reliably shade correctly for every shot and could be a pain to replicate from shot to shot.

Last edited by sentry66 : 05 May 2013 at 01:07 AM.
 
Old 05 May 2013   #41
Originally Posted by sentry66: Of course it's easier, but at the same time we have to be willing to learn things in order to write new shaders and software

We take energy conserving shaders for granted now after a lot of research was made.

We automatically dial in things like fresnel and refractive index settings because we've had to learn about them and saw a table of settings at some point (based on scientific measurements). We're not born knowing the refractive index for glycerol. I for one at least would have to look it up.

We can always observe it and wing it until it looks good enough for our shots, but if we don't have a good and reliable method to represent it in CG, it won't reliably shade correctly for every shot.


I understand what you're saying and what you're saying is true.

But I guess you're more a "shader technician" than a Director, Producer, Artist-on-deadline, or what you might term as "Shader users".

We shader users do not assume we will automatically use certain effects. Because we have to check for render times, and check it against shot intent and style. We also assume we are probably going to change shades every few shots, or between the first and second act for example.

Because all that matters to us is that it "looks correct" for the audience experience.

So I understand we are quite far in terms of point-of-view on this.

It's like if you're a flight engineer and you start proposing that you want to make fighter jets with a new wing shape - pilots will probably think "Why go through all the trouble? I kill baddies with the current wing shape just fine."

That's not to say you shouldn't study these things if you are in fact going to achieve higher shader performance - which shader users will in turn use to produce better pictures.

But you also understand this unsentimental view towards just focusing on the final image and not really caring all the time about underlying molecular principles is at the heart of artists who use shaders on a definite (and usually severe) deadline.

That said.. if you could choose "Eye Shader" the way you choose a diffuse color? That would make life easier I bet.
__________________
"Your most creative work is pre-production, once the film is in production, demands on time force you to produce rather than create."
My ArtStation
 
Old 05 May 2013   #42
I'm under deadlines just like anyone else. I'm a generalist, so I have to do a little of everything. Like a lot of people, I've had to come up with my own band-aid solutions and workflows when I've had time.

Mainly it's that over the years I've always neen working with the same anatomy subjects with the same (but evolving) models and shaders . I don't ever really get to shelve my work and move onto something entirely different since human anatomy doesn't really change.

So over time I've just noticed a lot of the shortcomings of modern shaders and techniques that I haven't always been able to simulate with textures or lighting/distance rigs alone. There are some tricks you can do with really complex shader setups (see my avatar), but I swear it could probably all be condensed into a single new attribute slider on a shader instead of shoe-horned into an existing attribute.

Last edited by sentry66 : 05 May 2013 at 12:37 AM.
 
Old 05 May 2013   #43
Originally Posted by sentry66: I'm under deadlines just like anyone else. I'm a generalist, so I have to do a little of everything. Like a lot of people, I've had to come up with my own band-aid solutions and workflows when I've had time.

Mainly it's that over the years I've always neen working with the same anatomy subjects with the same (but evolving) models and shaders . I don't ever really get to shelve my work and move onto something entirely different since human anatomy doesn't really change.

So over time I've just noticed a lot of the shortcomings of modern shaders and techniques that I haven't always been able to simulate with textures or lighting/distance rigs alone. There are some tricks you can do with really complex shader setups (see my avatar), but I swear it could probably all be condensed into a single new attribute slider on a shader instead of shoe-horned into an existing attribute.


Ah... well psychologically I revel in "band-aid" solutions... It's a strange quirk. I'm very old school - so I laugh in glee when people look at a flat matte painting backdrop we did and they say "That's a fantastic and deep landscape!"

I love things like that because I feel like I've engaged people's imaginations - with something really "low-rent".

So in a strange way, I'm happy to "band-aid" eyeball shaders and things like that.

That said, of course someone like you coding new shaders for the eyes would be great... we can't all have "Trickster Mentality".

But that's probably what I'd be interested in.. NEW SHADERS... but their use wouldn't be guaranteed for the likes of me.
__________________
"Your most creative work is pre-production, once the film is in production, demands on time force you to produce rather than create."
My ArtStation
 
Old 05 May 2013   #44
just read the entire thread
really quite interesting

except for sentry 6666

ban pls
 
Old 05 May 2013   #45
Originally Posted by cookepuss: Skin. Eyes. Mouth. Proportioning. Symmetry. Rendering. Quality. Delivery.

When looking to make a character less obviously CG, those are my top 8 things to look out for.

1. Skin. Real skin is complex and layered. Unless somebody has abnormally oily skin or sweats a lot, real people aren't that glossy either. Too much or too little can make a character seem plastic or wooden. Skin also isn't 100% opaque. Skin has this slightly translucent quality that can be mimicked through careful and measured use of subsurface scattering. Skin that's too CG often looks like that of an actor who's wearing too much makeup or foundation. Real skin is also flawed. Little nicks, bruises, burns, or blemishes give our skin character.

2. Eyes. Those can be a dead giveaway. If a character appears too alert, that can look fake. If the eye material looks too glassy , that can look fake. If the character blinks too much or in an identifiable pattern... fake.

3. Mouth. Facial posing/animation is tricky. The lips don't just move up & down or side to side. There's forward & back movement too. There's also some tongue action, which lots of animators ignore. Real people aren't cartoons so don't over exaggerate. Real people tend to be more subtle. Also, when posing the mouth, break that symmetry a bit.

4. Proportioning. Sadly, most people aren't the heroic 8 heads tall our art teachers taught us to draw. Unless you're built like a supermodel, athlete, or movie star, there's a good chance that you're probably just a mere 6-6.5 heads tall. Nothing wrong with that. It's just that real world proportions are kinda boring. Real people, even generally attractive ones, are less than ideal.

5. Symmetry. We're used to modeling with it. However, nobody is 100% symmetrical. It's like the old saying, "If something looks too good to be true then it probably is." Real people are kinda asymmetrical and imperfect.

6. Rendering. This encompasses a lot including: Lighting. Camera settings/setup. Staging. Shadowing. ETC. Those things aren't easy to balance, even with real world photography. I've seen a number of real world scenes look like CG because somebody went crazy and overproduced a shoot. Don't rush the results. A good render takes time and patience. Not just at render time, but also at post.

7. Quality. Similar to the issue of symmetry, you have to keep in mind how imperfect the real world is. It's dirty. It's all scratched up. Colors fade. Materials wear down. Things dent, bend, or break. All of this stuff kinda applies to humans. We're imperfect. Understand the difference between believable and realistic. Something that is realistic is also believable. However, something that is believable isn't necessarily realistic. If you're going to make something realistic, you have to sit down and embrace all of those flaws and complexities. The more you do, the more people will buy into it.

8. Delivery. Ever watch WWE wrestling before? Notice how the guys never get hit hard, yet always seem to scream in agony? That's what you have to do sometimes when it comes to CG. Sell the scene. Even the best character will look fake and boring if you have him on a plain backdrop and doing nothing at all. Even in stills, a character can appear to be animated. I'm not necessarily talking about big actions. Sometimes, pose and nuanced expressions can sell the character. A slight raising of an eyebrow. A slight shift in weight. How the character "communicates" with the chair he's on. We all live in context. We interact with our world. Our expressions reflect our thoughts. Those "dead" characters sometimes seem dead because they're not thinking about much of anything. Get your character to act, even if it's subtle. Get him to think.

Lots of things can go into making a character more alive VS wooden. Photograph and video yourself or others. Try to break the scene or still down. Observation is a very powerful tool. Use it.


I agree 100% with all of this. Good expanation cookepuss.
 
Thread Closed share thread



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
CGSociety
Society of Digital Artists
www.cgsociety.org

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump
Miscellaneous

All times are GMT. The time now is 03:01 AM.


Powered by vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.