"Why it’s so hard to make CGI skin look real" - VOX

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Comments

  • DartanbeckDartanbeck Posts: 21,564

    Yeah, procedural also presets more problems than those mentioned. For example:

    Each pore or blemish really needs to have some sort of displacement involved with it, or it will just look like added color.

    The color needs to work with the displacement to radiate color differences as it comes from the deep to the bump and back to normal height.

     

    When artists take high resolution images of real skin, this really helps to solve much of this dilemma.

     

    I must say - Kudos to those who make really good map collections that work together well to make great skin. Basic and Okay skin are one thing, but to really get it right takes hard work. So I guess it's fitting that a really good procedural shader would take a lot of hard work too.

    I imagine that a good set of masking maps could really help the process along, because I'm sure that there are shader geniuses around that can solve those things I've mentioned above, along with the complexity of wrinkles and such - and then to have them remain with the figure as the shape changes during expressions and such. Like the way a texture map will automatically stretch - causing at least some form of variation in what the pores and wrinkles are doing as the shape underneath changes.

     

    ...and I get it. Where I live it would be highly unlikely to get a real person to pose for digital scanning. So if I wanted to 'make my own' textures, I'd either have to buy in the skin maps from someone else, or go procedural.

     

    evilproducer has a procedural shader that he likes and uses all the time. I think he even offers it up at ShareCG. While I totally applaud what he's done with it, and am glad that he enjoys it, I always recognize it from a mile away as being procedural. I don't want that even if I was going more Toon than I am.

    This is not a rip on my good friend evilproducer, just an observation in the tastes of two individual artists is all! He can get a Lot out of Carrara that I can only dream of!

  • DartanbeckDartanbeck Posts: 21,564
    edited August 2021

    Dartanbeck said:

    This is not a rip on my good friend evilproducer, just an observation in the tastes of two individual artists is all! He can get a Lot out of Carrara that I can only dream of!

    Just like my above opinions are absolutely not a rip on anyone else doing this stuff! I truly applaud the work... I really do!!!

    Post edited by Dartanbeck on
  • mschackmschack Posts: 337

    Well in the end if you are doing a close-up still image then texture maps are required.  If you are animating you can get away with a lot and with animation skin is the least of your problems.  

  • Steve KSteve K Posts: 3,234

    NY Times review of "Ladyhawke":  "What is remarkable about Mr. Broderick's work here is that he comes very close to transforming contemporary wisecracks - particularly, his asides to God - into a more ageless kind of comedy. Toward the end, when things are going very badly for Phillipe, Isabeau and Etienne, who is bent on sneaking back into Aquila to murder the evil bishop, Mr. Broderick makes something comically moving out of Phillipe's impatient but respectful, ''We've come full circle, Lord. I'd like to believe there's some higher purpose in all this. . . . It would certainly reflect well on You.'  ''

    I oredered a used DVD from Amazon, $7.  yes

  • MistaraMistara Posts: 38,675

    he was good in war games. too.

  • JonstarkJonstark Posts: 2,738
    edited August 2021

    Re: Ladyhawke: "I talk to God all the time, and... no offense, but He never mentioned you."  was one of my favorite lines, lol.  Also:  "She flew away." and when the Soldier begins to strike him: "God's truth!  She flew away!"  lol, so great.

    Post edited by Jonstark on
  • JonstarkJonstark Posts: 2,738
    edited August 2021

    Dartanbeck said:

    Yeah, procedural also presets more problems than those mentioned. For example:

    Each pore or blemish really needs to have some sort of displacement involved with it, or it will just look like added color.

    The color needs to work with the displacement to radiate color differences as it comes from the deep to the bump and back to normal height.

     

    When artists take high resolution images of real skin, this really helps to solve much of this dilemma.

     

    I must say - Kudos to those who make really good map collections that work together well to make great skin. Basic and Okay skin are one thing, but to really get it right takes hard work. So I guess it's fitting that a really good procedural shader would take a lot of hard work too.

    I imagine that a good set of masking maps could really help the process along, because I'm sure that there are shader geniuses around that can solve those things I've mentioned above, along with the complexity of wrinkles and such - and then to have them remain with the figure as the shape changes during expressions and such. Like the way a texture map will automatically stretch - causing at least some form of variation in what the pores and wrinkles are doing as the shape underneath changes.

     

    ...and I get it. Where I live it would be highly unlikely to get a real person to pose for digital scanning. So if I wanted to 'make my own' textures, I'd either have to buy in the skin maps from someone else, or go procedural.

     

    evilproducer has a procedural shader that he likes and uses all the time. I think he even offers it up at ShareCG. While I totally applaud what he's done with it, and am glad that he enjoys it, I always recognize it from a mile away as being procedural. I don't want that even if I was going more Toon than I am.

    This is not a rip on my good friend evilproducer, just an observation in the tastes of two individual artists is all! He can get a Lot out of Carrara that I can only dream of!

     

    Evil did incredible work, actually.  I'm not ashamed to admit I'm building on his platform (ripping him off, in other words).  I also found a pretty good Blender tutorial on youtube for procedural skin, which taught me how to actually use  the color gradient (I never really understood it before, to be honest).

    Although I was going for  'porcelein' pale look for this particular shader (the other 2 I'm tweaking are Tan and Dark), I realized after you posted the 2 pics beside each other that it still doesn't have enough skin imperfections.  As part of my shader includes part of what Evilproducer pioneered, and since his shader has a great little noise shader specifically for subdermal skin imperfections, I jumped into the color gradient to darken one end of the gradient, therefore drawing a tiny bit more contrast to see if I could introduce more skin imperfection.  It was already there, but I definitely had it too light, so that it blended in with the base skin color to the point of invisibility.  I want it to be just barely noticeable, or rather something that the viewer doesn't notice, but unconsciously helps sell the realism an itty bitty bit more.  The face was the only shader I altered here, you can see the contrast of the original shader on the neck and on the little bit right on the edges of the lip (I used Anything Goos on the lips to help blend from lip shader to face shader so it isn't so stark, but since I didn't alter it here there's a little ring of brighter color around the lips).

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  • JonstarkJonstark Posts: 2,738

    By the way, the Iris is irritating to me.  Sparrowhawke has a perfectly excellent Iris shader that I can't figure out a good way to use.  I use it on the lips for the bump channel actually.  But because Genesis1 has both eyes on the same shader, I can put Sparrowhawke's Iris on one side or the other, but not both (that I've been able to figure out).  This isn't to insult the Genesis1 developers, it makes perfect sense to put both eyes using the same shader.  But it is a bit frustrating to not be able to use Sparrowhawke's excellent shader.  

    Of course, I could simply remap one of the eyes, but then that would alter the shader so if I gave it away on sharecg no one would be able to use unless they took the time to remap one of the eyes into it's own shader too.

  • DartanbeckDartanbeck Posts: 21,564

    Wow. What a difference that made! Cool!

    I'm still a sucker for using EYEdeas 3+, but recently bought PhilW's Genesis Eye Surface, which comes with his Bright Eyes products bundled in. The Irides really weren't my big issue - mine was with the lack of the added eye surface. Genesis 1 is the only Daz figure to not include one.

    And, yes. evilproducer and I have met on several occasions and he really is quite a genius about a good many things. I love his art too!

  • DartanbeckDartanbeck Posts: 21,564

    mschack said:

    Well in the end if you are doing a close-up still image then texture maps are required.  If you are animating you can get away with a lot and with animation skin is the least of your problems.  

    I disagree.

  • JonstarkJonstark Posts: 2,738

    Dartanbeck said:

    Wow. What a difference that made! Cool!

    I'm still a sucker for using EYEdeas 3+, but recently bought PhilW's Genesis Eye Surface, which comes with his Bright Eyes products bundled in. The Irides really weren't my big issue - mine was with the lack of the added eye surface. Genesis 1 is the only Daz figure to not include one.

    And, yes. evilproducer and I have met on several occasions and he really is quite a genius about a good many things. I love his art too!

     

    Ever since you suggested it, EYEdeas 3+ was something I picked up immediately, and I do think it's a terrific solution.  There are some morphsets you can get that will allow much more realistic Cornea bulge and Iris correction for Gen1, I think I got them when I bought AoA's subsurface toon set (it came with it).  I could be misremembering though... but Gen1's eyes by default don't have realistic defaults and unfortunately not a lot of morphs to get them looking right.

    PhilW's eye surface is a terrific addition, especially Carrara lights let us light only specific objects in the scene.  So we can make it so that our regular light rig illuminates everything except for the eye surface, then add a duplicate light in the same place, much brighter, which only illuminates the eyesurface object, giving great eye highlights.  So it's kind of a hidden blessing that Gen1 didn't come with an eyesurface, since we can (thanks to Phil) add it in as a separate object.

    For my shader though, it had to be something that would go on a regular Gen1 essentially 'naked'.  I still prefer using the eyesurface myself though :)

  • mindsongmindsong Posts: 1,701

    Dartanbeck said:

    mschack said:

    Well in the end if you are doing a close-up still image then texture maps are required.  If you are animating you can get away with a lot and with animation skin is the least of your problems.  

    I disagree.

    it'll be interesting to see more about the 'lenses' being used in the discussion here.

    to wit - which would be more bothersome or distracting to a viewer - blocky animation movement - unconvicing blinks, etc., or waxy skin in a close-up? Subjective, of course, but one doesn't discount the other - it just forces the animator to pick their battles based on their time, skills, OCD, and taste.

    LOD on skin/textures makes that problem more managable, as do billboards and skydomes for backgrounds - if done well enough (not distracting).

    Chunky motions can wreck a scene's magic, but can become a 'style' if they suck consistently :) - willful suspension, etc.

    To my approach, I think when on the edge of the uncanny valley, if one is consistently on one side it works, but if one bounces back and forth, it *really* becomes a distraction. This is to say that I'll probably (personally) pick the plasticy skin (hidden in toon?) and rough motion side enough to not be posing like a badly-done realistic (but fail) approach. I don't think I can pull off the realistic approach consistently enough. My few magic frames aren't enough to carry the rough edges - at least not yet. Dart, I think you're right there and are consistent enough to pull it off with your chosen styling, but consistency is the key, I believe.

    I've also seen some pretty good stick-figure stories that carry the story, sometimes better than the cgi-epics that fail to impress - a function of the story more than the tech, etc.

    curious where this goes.

    best,

    --ms

     

     

  • JonstarkJonstark Posts: 2,738
    edited August 2021

    mindsong said:

    Dartanbeck said:

    mschack said:

    Well in the end if you are doing a close-up still image then texture maps are required.  If you are animating you can get away with a lot and with animation skin is the least of your problems.  

    I disagree.

    it'll be interesting to see more about the 'lenses' being used in the discussion here.

    to wit - which would be more bothersome or distracting to a viewer - blocky animation movement - unconvicing blinks, etc., or waxy skin in a close-up? Subjective, of course, but one doesn't discount the other - it just forces the animator to pick their battles based on their time, skills, OCD, and taste.

    LOD on skin/textures makes that problem more managable, as do billboards and skydomes for backgrounds - if done well enough (not distracting).

    Chunky motions can wreck a scene's magic, but can become a 'style' if they suck consistently :) - willful suspension, etc.

    To my approach, I think when on the edge of the uncanny valley, if one is consistently on one side it works, but if one bounces back and forth, it *really* becomes a distraction. This is to say that I'll probably (personally) pick the plasticy skin (hidden in toon?) and rough motion side enough to not be posing like a badly-done realistic (but fail) approach. I don't think I can pull off the realistic approach consistently enough. My few magic frames aren't enough to carry the rough edges - at least not yet. Dart, I think you're right there and are consistent enough to pull it off with your chosen styling, but consistency is the key, I believe.

    I've also seen some pretty good stick-figure stories that carry the story, sometimes better than the cgi-epics that fail to impress - a function of the story more than the tech, etc.

    curious where this goes.

    best,

    --ms

     

     

     

    Stick figure fighting!  

    Actually though I think there's some controversy on this one, it seems it was a direct copy of a Naruko/Sasuke fight, where the artist simply traced stick figures over the original animation.  But if no one know, it wouldn't lessen the impact and storytelling at all.  :)

     

    Dart's got Rosie, which although he does damn fine realism rendering in his animations, the facial shape (though cute and appealing) is distant enough from human that I don't think there's any worry of crossing the uncanny valley.

    Actually the Dart figure is pretty realistic though.  Dart just curious, but where did the decision come from to go with sorta different styles, I'm guessing you easily could have used a bit of Hiro morphs to make the Dart figure less human real, so I'm assuming it's intentional, maybe part of the story?

    Post edited by Jonstark on
  • DartanbeckDartanbeck Posts: 21,564

    Oh, right. I think I may be getting misinterpreted here.

     

    While I think that one has flexible options on choosing what sort of skin the characters have, I just disagree that such a choice is not important.

     

    But then again, my characters are what will be carrying my stories, so they have to count. Their skin choice is very important.

  • DartanbeckDartanbeck Posts: 21,564
    edited August 2021

    Yes, jonstark!

    Getting realistic eyes can be a task. I used to buy character packs (for V4) simply to add their textures to my map arsenal. (Still do, actually)

    There's also Indigone's awesome  Endless Eye Kit for V4, which I don't use, but like the approach very much. That's a combination of procedural and map mask.

    For that matter, V4 Skin Shader Kit and Lights is a procedural set for "Basic" shaders for all of V4, but since they're procedural, they'll work for any surface.

     

    My skin shaders originated from that kit, but have since been massively altered. The awesome manual that comes with that kit (I haven't read it in too long - time to revisit) is fantastic, and taught me a lot about shaders in general.

    But I use the Cornea shaders from that kit on my EYEdeas 3+

     

    Also for EYEdeas 3+, I keep the Iris to its own shader, rather than using the same one as the eye whites, etc.,

     

    Using the suggestion from Digital Lighting and Rendering from Jeremy Birn, I recess the Iris into a concave cone, put a color map in the highlight channel and set that to somewhere around 7 to 9 so that light shines across it pretty well, but then stops before filling the opposite side of the cone. This gives me a fairly decent iris gleam that I've been fairly satisfied with for the most part.

     

    I can't remember which collection it is that I've been using for the maps. I use the remapped EYEdeas 3+ so that I can use V4/M4 maps, and the ones I use are from a Surreality folder in my V4 texture maps called SG something or other. There's a huge selection in there, so I combine one shade in the color channel with another for the highlight, and then I used Materialize to create a Normal map using the bump map that corresponds with those maps.

     

    This all results in the irises almost glowing, but without putting anything in the glow channel. They need to be lit. But with that cornea shader with that Iris shader and then putting Glass or a water shader on the reflection layer, I don't even use light linking for them anymore. They just work.

     

    For Dart's initial tests in Carrara (and in Studio, for that matter), I've just been using the Genesis Eye Surface with Bright Eyes shaders. I love it and am embarrassed that I didn't buy it when it first came out, like Headwax said I should! :)

    Post edited by Dartanbeck on
  • DartanbeckDartanbeck Posts: 21,564

    Like she instructs in V4 Skin Shader Kit and Lights, I often begin with her shader kit and then replace the color with a texture map.

  • JonstarkJonstark Posts: 2,738

    I had forgotten about both of those excellent freebie kits, even though I've learned from both approaches.  Unfortunately the Iris shader from the endless eyes kit is not entirely procedural, actually had has 3 different maps to guide the effect.  And the V4 skin shader and lights kit has placeholders where texture maps are meant to replace the color she has set there.  Sadly neither will give me the procedural Iris I've been hoping to figure out.  I've mimicked Evilproducer's approach so far, and it's good enough from a distance.  I just wish I could figure out a way to use Sparrowhawke's shader on both eyes without having to remap one.

  • JonstarkJonstark Posts: 2,738
    edited August 2021

    Muhahaha!  (cue Charlton Hesten crying out "You maniacs!" and Dr. Frankenstein: "It's Alive!")   

    Finally cracked it tonight (staying up past my bedtime), figured out a way to put the Sparrowhawke Iris shader on both eyes.  Had to switch to flat view, drew 2 oval layers, put an Iris shader in both.  It works!  lol, time for maniacal laughter.  Now I don't claim that I'm very good at coloring the shader, so this looks a little bit more electric blue/green than a natural eye iris probably would, but hey... proof of concept.  :)

     

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  • DartanbeckDartanbeck Posts: 21,564

    Oh very freaking Cool, Jonstark!!!

  • Steve KSteve K Posts: 3,234

    Jonstark said:

    Finally cracked it tonight

    Pretty convincing, nicely done.

  • JonstarkJonstark Posts: 2,738
    edited August 2021

    After a few days where life interrupted, got back to my testing/refining.  Added and oval layer on the upper chest, and on each shoulder.  Seemed like natural places for freckles to occur.

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  • DartanbeckDartanbeck Posts: 21,564

    Very nice work! A couple notes, just from personal preferences:

    1. It looks like the shoulder oval to our (viewer) left might be too large for the domian - unless that's some other clipping causing that little seam look
    2. It also looks a little too grey for human skin

     

    But those are very minor. Overall I really like what you've got here!

  • DartanbeckDartanbeck Posts: 21,564

    Also, a big requirement for 'realistic skin' is lighting.

     

    It's difficult without a bunch of practice, using skills learned from photography and so forth, because I notice that (myself included, when I was first starting out - and for years) we want our people to be seen!

     

    Cinematographers and photographers understand the importance of shadow and highlight. I never did. The three-point lighting examples in the Carrara browser are an excellent example of how to begin, but we still need to practice and perfect this - not that I'm anyone to talk. I'm still working hard at trying to design better lighting.

     

    I just saw this in the Gallery - an entry to the Swords and Sorcery contest by Saidge42 

  • DartanbeckDartanbeck Posts: 21,564

    The reason I went looking in the Gallery is that, when I took my stint into learning Daz Studio better, one thing I noticed with from the start is that modern Daz 3d base figures and their Iray PBR textures look fantastic right out of the box in Iray.

     

    I'm not trying to drive folks to learning Iray. I just wanted to show that the gallery is filled with great examples of how good CG skin can actually look.

     

    Good Iray renders are often achieved by using a combination of HDRI global lighting along with practical lighting added to the scene - much the way a cinematographer or photographer would work professionally.

     

    Combine great lighting with great shaders and I bet you've got winning CG skin!

     

    As seen in my Character Design method, I use a standardized light rig for all of my character design. I do this so that when I optimize my characters for the browser, they're all using compatible lighting. 

     

    Even if I completely change how I light them, their shaders are designed to work with the same situation (lighting and background) so they're all consistent with one another.

    Of course, the shader examples used are very basic - but still look pretty good, I think.

  • JonstarkJonstark Posts: 2,738

    Good eye Dart, the seam on the shoulder is alas my fault for hiking up the highlights on both the torso and face, but forgetting to also amp it up on the arms.  The arms shader is about 10% less bright in specularity, due to a slip-up on my part (previously I was testing how much specularity I could hike, til it was obviously 'too much' and since I was zoomed on on the face and neck I didn't bother to change the arms). 

    And I also agree that it's slightly too gray.  It's a trade-off when trying to make the skin actually kind of gray and let the SSS do the work; I had read somewhere that that was the best/most scientific approach, but I'm finding it doesn't work well in rendering, so I added a bit more color to it instead.  Not quite enough though, needs a bit more to avoid the gray effect I think.

  • Steve KSteve K Posts: 3,234

    I'm watching a lecture series on Leonardo da Vinci, the professor spent a lot of time on this painting.  A young apprentice Leoanrdo likely painted the angel at the lower left but not the other figures, a common practice in the workshops of the time.  This was said to be an advance in rendering the human form, using subtle light and natural settings/poses.  It was also an early example of painting with oil rather than egg tempera.  The rest, as they say, is history.  Actually this is history, too.  cool

    https://en.wikipedia.org/wiki/The_Baptism_of_Christ_(Verrocchio_and_Leonardo)#/media/File:Verrocchio,_Leonardo_da_Vinci_-_Battesimo_di_Cristo.jpg

  • Steve KSteve K Posts: 3,234
    edited August 2021

    A contemporary of Leonardo's was Antonello da Messina, considered the best portrait artist of the time in Italy.  He brough the oil portrait techniques to Italy from Northern Europe, techniques that allowed more realistic images than were possible with the traditional tempera paints.  I'm pretty sure Pixar would have hired him.

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  • DartanbeckDartanbeck Posts: 21,564
    edited August 2021

    Just something that kinda freaked me out when I first started my hand at learning Daz Studio not long ago, is how nicely the newer Daz 3d figures render right out of the box using default Iray settings.

     

    It's always been on my mind to try creating a similar shader/lighting setup within Carrara, even though in reality I actually operate in an entirely different way when I'm in Carrara.

     

    But just to show what I meant earlier about all of this, here's an example - just loading in Sol and giving her one of her eye color presets, some Bronwyn Hair and opening her mouth and lips a little, this is Iray about 50% through the render.

    If you click on it you can see how the normal mapped bump isn't exactly perfect, but I think that for a simple load and go situation, this skin looks pretty darned great.

     

    So I'd like to make some PBR shaders in Daz Studio and try them out in Carrara using Philemo's awesome plugin. See how it turns out.

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  • DartanbeckDartanbeck Posts: 21,564
    edited August 2021

    Using my usual shaders and default scene for Rosie 5.2, I bumped up some remder settings in Carrara to still be fairly mediocre as far as Carrara render settings go - but high enough as to where it took three times longer to render that Sol in DS/Iray

    Oh... and the hair is still set at the 'distance' appearance, as I was only thinking about the skin shaders.

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  • VyusurVyusur Posts: 2,235
    edited August 2021

    I don't know about other figures, but my figures are best rendered in Iray. Carrara is good enough for decorative purposes.

    As for skin realism, Carrara doesn't have many of required features such as correct SSS system. From my practice, the best result is a mummy-like skin, and non of the efforts (even with octane) can give desired oilish skin look.

    Here is a couple of examples of my recent figure rendered with Iray.

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