How to Render Realistic Skin | ep#505

hey what's up everyone and welcome back to my channel in today's um today 505 I will be focusing about skin shading with the new AI standard shader lots of you guys have requested that I should show you guys how to do proper skin shading and how the new shader works lots of you also said it's a really bad shader and I want they want the old shaders back but honestly I don't agree with that I think the new AI standard shader is pretty awesome and I'm not getting paid to say that I honestly think it's good and it has the same functionality as the AL shader it might be a bit different design but you can achieve all the same results as you can see here in this Logan shot this is rendered in Arnold skin shader and then this character as well as done in the new Arnold 5 shader so there are lots of things you can create with that and it's super advanced shader where you can do lots of different things the only difference to the AL shader is that you don't have the distribution modes in this msss so you don't have directional and all that fancy stuff but you have the empiric mode which is pretty good and very well maintained by a solid angle and very efficient as well so before we start though I want to make you guys aware that I am on patreon and I would really appreciate if you would support me here just to keep me motivated to create content for you guys yeah so the link will be in the description below if you want to check it out become a patron of mine that would be really cool so let's jump into Maya and I will show you what I will be showing you today so this is my R D test which I did today kind of happy with the result obviously facial hair and hair in general is missing but this is about skin shading right so I just want to show you this is created with the a5 standard surface shader you can see all the nice detail in the skin pores you can see the subsurface scattering happening in behind the ear it is because I have a pretty strong worm light now and but you can also see the same effect on the bridge the nose around here and also in the corners of the lips so I'm pretty happy with the result honestly and if you want to follow along or if you want to test your shaders you can access these or download these materials on the USC webpage just be aware you cannot reset resell them and cannot use them commercially this is a research website where you can access those Alembic files and textures and create your shaders your lighting just to see how everything works and I'm pretty sure that all of you have access to a light stage and elate a light sage is a rig where you can create proper lighting setups and extract all the surface information like diffuse like raw diffuse and specular passes as you can see here so this is more based to show or this will be just to show you that it is possible obviously you need to go into re and paint these maps yourself and add as much detail as you can so back to Maya let's just save this image it's stored at the bottom I hope I won't crash but anyways so let's just actually export this quickly on unless you later so anyways okay closing this and I will assign let's just first clean this one up this is the Rd let's just rename this guy call Rainey on this anymore oh just on updating okay this is a training and this will be our D there we go so this is the setup for the current shader and I will just copy the displacement because this is not part of the tutorial I will just bring this to the training one over here there it is and I will select head or let's first create a new AI standard there we go and select the head and assign to selection and let's just rename this bad boy to AI Emily skin I just call this them head there we go so this is a training shader I like to rename everything to keep it in the night naming convention and I will just connect the displacement directly to the shading engine so let's just save this as our do one training or one just to keep everything nice and clean and I will bring over the raw textures these guys as well okay so and before we start I will just create I make strange I think it's called no I'm sorry I mean what I was it called actually layer oh man what is it damage sorry I just want to create a I'm the also not so familiar with those all those new names so let's just quickly find it in here Arnold shaders I think's which is what I wanted exactly switch so I just want to connect all these colors quickly into these out with just that I can use isolate selected to quickly see how all these inputs look like so connect this to the base oh that's not connected to here connected to just specular color subsurface color is good just for a test I will disconnect it in a minute okay let's start the render oh let's see I need to enable progressive I have pretty high subdivisions just to get this nice detail so it always takes a bit until Renner is starting I think I will just dial down the subdivision so this will be a faster process and this did not work let's try this again this needs to be on progressive there we go and let's change the resolution to be 50% for now okay well let's try 75 okay there we go right so and if I switch this to light and you can see how the lighting look like so I've got one strong key from the right which gives me nice shadows on the cheeks I've got a fill for the shadow side and I have a rim for the backlighting of the ear so you can see this is now kind of what the file will be and this is the base textures the base diffuse so let's head over to isolate mode and I just want to show you how the maps look like this basement map looks like this the fuse is this one it's pretty flat but I'm viewing this in srgb so the linear color would be looking like this so let's head back over to srgb and then we've got specular which will be just the intensity because we have a micro displacement map as well which breaks up the surface to give us this micro roughness so we don't need a pretty detailed roughness map then we have single scatter single scatter is used to mimic a single sss scattering event which is which introduces a tiny bit of diffuse and this is exactly what the directional or diffusion model in the AL surface does so it's a kind of yeah it's kind of similar to the al shader when you use this and this is the micro displacement it is very high detail and it's like a high frequency noise of nice detail I can actually show it to you in Nuuk how it looks looks like where are we so that's actually the nose you can see it's pretty high res let's just stop this up so you can see something so this would be the micro displacement so I will use this as well to break up the details based on map in general so this is the raw displacement and then I will just merge them together to get to combine these two maps and this gives us a super nice detail break up on the surface okay so what is the next step I showed you the lighting I showed you the diffuse of the raw textures and they are just takes converted so nothing special going on here everything is set up to raw because they are Excel files and my Arnold version is two point zero zero one one score five point zero zero one as well right okay the first step I guess would be to bring in the yeah let's try to bring in the diffuse color and the first step what you would do thing to do is just connect this to the base color and then you want a subsurface right so the next step would be then to connect the out color to the subsurface color as well and then you have the subsurface radius and you've got a subsurface so what is what are these values so this is the weight fully one means full subsurface scattering no diffuse components in here we will plug the single scattering event so we have a tiny bit of diffuse contribution as well the color would you can think of is the basic like the surface color of the skin or whatever and the radius is the color which is being scattered so for simple sss you would just have a floating point color which is a gray grayscale value right so red green and blue are the same value this this means that the light which travels through the surface we'll have the same color for red green blue so how would you mimic now these sub dermal layers of skin because you want to have like red is traveling the farthest then yellow whatever like you have these three layers in the al surface shader right this is kind of exactly the same so what this means is if you have your red green and blue channel and let's say you want to create skin the skin sss color is red because the red light travels the furthest into the material so you want to have a pretty high red contribution less green and even less blue so for a proper skin or like a realistic skin you have let's say a value about this and then green and blue so this is kind of the color you would get and obviously can map that and we will do that as well and this says that the Ray the red ray travels the farthest then the green and then the blue so this is the yeah the measurements kind of what it is and then you have a multiplier so if you crank this up you brake physicality or depending on scene scale this is a multiplier for the scattering effect and that's kind of all you need to do or need to have to get it to work okay so I have the same diffuse color for the fuse and SSS color so what I like to do I just in case I want to recolor it I just create a remap color in here and the out color connects to these two guys again so that's nothing special right and then we have a single scatter guy I won't connect this right away but in a minute as well and then I want to color grade the diffuse color to create like this radius color which will be the these the skin layers that say and I will use a multiply node AI multiply if you don't have a node you can just create multiple divide note it's the same thing just RGB and this would be as well RGB like this so that's kind of the same I'm not sure if you have this node anyway so connecting this guy to the input and the outcome goes to the radius and currently it's wide so that's the same color and I hope you follow along it should not be too crazy I will explain it when we start the renderer just now I did not change the subdivision I will do that now I will cancel the render quickly and just change subdivision amount to be not as high let's just wait for it to start there we go let's stop it again and go to the head and change the subdivision amount to let's just run out stay on to and start the render again and we should be a bit faster to start there we go click the play button and now you can see this is what we get out of the box by just connecting those Maps right looks kind of like waxy like Madame Tussauds kind of style so before we start I want to disable the reflections the specs so I just disabled them completely so we have a proper wax figure now let's go back to isolate magis that you can see what's going on so that's the diffuse and this is kind of now the same color for my skin tones right so what I want to do for the radius now I want to create like a flashy color so I want to multiply all the colors by a red value so let's just bring in some saturation and reduce the gain more saturation and you can actually change it should be somewhat red and obviously you can spend way more time on this to create a proper blood or flesh tone if you have more you want to see more fat like a chubby person whatever you can actually paint the radius color a bit more yellow in certain areas orbit dark on other areas again if you want to create a vein for instance you can paint them in here pretty black and then you want you will actually see them through the SSS so this is something where it can spend lots of time to create very detailed subsurface scattering maps but for this I will just show you this approach to multiply the diffuse by kind of dark red and then you get this flashy tones which will kind of be your depth right and then this is my skin base color my raw unlike unlit Road if you texture and I think it's a bit too white like - to desaturate it and I just wanted to bring in a bit more values into that so I use the wrong node there's a remap HSV to change saturation so I will just plug them in here as well I could have replaced a color node but I'm just not reconnecting this guy up hitting the Save button let's just bring in some saturation so this is the Sun let's try something of 0.3 maybe a bit too much I guess let's try 2 5 and this is trial narrow right so nothing is like fixed so I'm just testing out values and see how they look maybe a bit too bright as well and you need to remember the brighter the SSS like the yeah the brighter the lighter the texture the more light travels through it so and on the contrary the darker the less scattering effect you will see so just keep that in mind so let's see how the shade it looks like now and this looks way better than before it's not as yellow anymore you can actually see some some nice color bleeding of the ear here and even on the nose bridge you can see that there is actually a pretty cool effect going on already and now that's what I'm just doing like these simple changes right and I think honestly this looks already pretty cool obviously we are missing the specularity and we still did not connect the single scatter which I will do now so the single scatter is a map which indicates which part should show the fuse so no SSS and which part should show SSS the extracted texture is needs to be inverted so I will create a reverse node which is a invert connect these guys up and the out color red goes into the subsurface slot which is this should be the weight right this is just simply connected and let's just render and I will show you show you how the map looks like now it looks like it's wide but there's some minor values on it so you can see in the bottom here you have 0.5 0.9 5 4 ranging in this area so everything which is like this just means like there's a five thing it's 5% diffuse contribution on these parts sometimes more sometimes that's it's hard to see with this let's just see if we can change the gamma a bit to see something there we go so you can see what's going on here so these lip areas in the nose is fully sss and then of the years fully sss and then you have some diffuse contribution over all so this is kind of what it's doing it's a minor effect and it's hard to see in the render like if you compare a and b you can maybe see it but it just gives a general more realistic feeling to everything okay so that's connected up and now let's check the specularity so as I was saying the displacement map has this micro detail on it so typical shaders make those micro faceting on the surface using roughness right so for this shader for this character because we have this micro displace and we don't actually need a proper roughness map because the micro displacement is showing or telling the shadow hey this is pretty high frequency and it breaks up the specularity automatically okay so all I got to do is connect I call it spec r but it will go into the specularity weight into the slots of the red channel will connect into the specular map and now we have a sweaty character obviously this is not correct we just need to increase the roughness overall so we can actually check the specular dollar again we can see what's going on so let's try to bring this up to 100 point five and then you actually see some nice skin reflectance values and this is actually pretty close to the real reflections which you get on this character here let's just see if we can pull it up a bit bigger no we can't well here you can see it's actually a bit more shiny so but here it's working pretty good so what we can do is we can just bring down the roughness a bit just to create what did I do now did I break it today delete the skin no what did I do interesting think I change your roughness or something let's just double check when I what happened I think I actually deleted the shader let's just undo yeah oops sorry about that let's just start again I saved and restarted let's see if we can get it back there we go all right so isolate again sorry I meant specular again there we go and as I said I think it's a bit too rough comparing this to the reference images so let's just bring the roughest down to maybe four five and you can see we get something nicer here for skin the IOR it I think five two is not really physical I think it should be use kind of like water what effect so it might just go down a bit so it's overall not not as reflective what else so roughness is 0.45 and obviously if you want to have like wet lips em you would need to either paint a roughness map so obviously I did not do that now was just plugging in the textures directly just to show you how it's actually working so let's just render those the lip area you can see it is maybe it might be a bit too too rough but you can just as I just said in Mario you're painting a package just paint a little roughness map just to create more shiny lips also maybe around the eyes or on the forehead something more shiny but I think this looks actually pretty good we can maybe go down to 0.4 and check the nose how this looks now I think this is pretty good yeah so I will be checking this out let's compare this to the previous one I think they are actually pretty close yeah so I think this one is a bit more saturated and darker so it's not as Caucasian white it's a bit more tan I guess but in in general this is how to shade a skin trade a skin character with a subsurface scattering and for the ones who complain about the shader I think this is a good example to show you that you can create pretty realistic results just with this simple in quotation simple shader you get lots of detail and you have all the sss maps as well this is the sss albedo which is the raw sss input map then we've got the direct and then the indirect sss which is bounce stuff what else is interesting diffusal various i think you special yeah so let's see if we can check something more see what else is there to talk about talk about the scale rate is that all clear i guess and yeah i think what i forgot is the wage did i don't know why it is 0.8 on default it's a bit confusing not sure what the reasoning is the default value for the diffuse color is the weight is 0.8 so i tend tend to forget that so this should actually be b1 which will trigger on your render which i didn't want to do but anyways it is now re-rendering let's just see the diffuse direct you can see it's pretty low because this is this is being driven by this map and you can see that we've got a really small amount of diffuse contribution to the shader and mostly is driven by the SSS so these two get added together plus the specular indirect and direct and then you get the beauty pass yeah so this is that yeah I think this is pretty much it regarding the realistic skin shading obviously feel free to leave any comments below any questions I will try to answer them and for the people who are reading those comments and you guys know the answer ready Jen just feel free to comment on some questions or something because I cannot always reply so that would be a very help for me and I've also seen that lots of you guys are not subscribed yet because more or less assisted statistics say it's like 60% of all the viewers are not subscribed to my channel so I would really appreciate if you would subscribe to always keep be aware of new tutorials push online and especially for my live sessions which are very spontaneous and you will get a notification which is telling you hey I'm online and presenting something so thanks again for tuning in and yeah thanks for your requests for new tutorials I will be working on a new volume shader because that was requested as well and also some different metal types but they will be coming I'm not sure when there is no specific dates yeah so thanks again sorry for me going on and blabbing around so stay tuned keep question asking questions I'll try to help and thank you again Cheers

Channel: Arvid Schneider

Views: 160,037

Keywords: 3D, Tutorial, Maya, Learning, Arvid, Schneider, urs3d, training, mtoa, render, teacher, advanced, skin, shding, sss, scattering, subsurface, human, realistic, arnold 5, solidangle, beginner, autodesk, rendering, arnold

Id: ss13J1emsvw

Length: 27min 11sec (1631 seconds)

Published: Fri Jun 02 2017