Hey everyone! I recently finished my Michael Clark Duncan likeness project (The Green Mile) and I thought it would be a good idea to do a little post mortem. If you don’t know what I’m talking about you can see it here: https://www.artstation.com/artwork/Qr4mwd
This post mortem is meant for both myself and others benefit (do you trust me? ) :D Good! This project started out as I was taking the art heroes likeness program to push my ability to do stuff like this. That was an amazing experience and I can’t say enough how much I recommend people go check it out! http://artheroes.co/likeness-program
Anyway, ideally this would be an open forum and if anyone has better ideas please feel free to share. The stuff I am about to discuss is a combination of what I learned in the course and thru my own trial and error tests. It is by no means the only and best way, although I think its safe to say its in the right direction at least.
So I’m not gonna talk about everything involved in making a likeness, I thought I could focus mostly on texturing and materials in marmoset 4, as in my mind that was the most mysterious part about this whole process. Luckily marmoset 4 is a beast and anything you throw at it looks pretty good out of the box, but the goal is to really make stuff as good as possible not just passable. So here are my material settings for everything lets focus on the head tho as the rest is sorta obvious texture wise. The first image here with the red highlight titled "Head" is the Head material I ended up with. (I have included images of the other materials at the bottom for those interested).
So you will notice there really is just basic stuff in that head material. Probably the 2 things that are not super clear is what the “MCD_Head_DetailMap” is, and what specific Detail Normal Map am I using.
The detail normal map is what comes from the 3d scan store whenever you purchase something that comes with a marmoset scene. All you do is plug that in and set the tiling to something reasonable and its done. You don’t have something from the 3d scan store you say? Well think about purchasing something because its an invaluable resource if nothing else for reference with how pores and stuff should look. Its not too expensive either.
Now the “MCD_Head_DetailMap” is something we covered in the art hereos course. It pulls out all the stops in terms of using baked maps, but essentially all you need to think about here is where these tiny skin normal details might be found on a face. Are they in a deep pore? No?... so lets leverage the cavity map and multiply black on the pores. Are they not gonna be on bumpy parts of the skin like the neck? Cool, the ao bake darkens that area a bunch. If its not perfect its no big deal, these are tiny details end of the day. As long as you understand the theory behind it you can make a cool detail map. You probably don't even have to bother with hand painting stuff on this one.
Lets talk about the scatter map now. This one is pretty easy. Thinner areas will scatter more like the ears and nose while thicker areas will not. You could practically not even use a map here and leave it white cause marmoset is a bad ass and will work its magic anyway, but to push it more I used the thickness bake to make some areas slightly darker and jacked up the scattering a bit higher. You can get the gist of it looking at the tiny thumbnail in the material image posted.
Albedo: You can steal textures from faces like on texture xyz or 3d scan store or just the good old internetz. Project them however you want, there are tons of tutorials on that, I used zwrap and baked the maps out. Once baked I blended mostly texture xyz bake, leveled it a lot (comes super dark for some reason) and then I used a bit of 3d scan store to cover the holes. These maps will be a lot different, so I blended them in substance painter, but you can do this in photoshop its just harder to tell where you are going with it in 2d I feel. After lots of leveling and blending, I clone stamp stuff and even hand paint bits till I have a decent base. Did I mention I level and hue adjust? Yea, you’ll really need to do a lot of that to make it feel right. Some areas will come in way too dark like ears especially will have darkness baked in. The rule of thumb is albedo should NOT have light info baked in. So that stuff is straight up wrong if you don’t fix it. So again, clone stamp and painting will be the easiest method to correct this along with any baking errors you might have. “One cool trick doctors don’t want you to know about” is that you make a base with the albedo via steps mentioned above, and then leave it there till the end. You don’t want to call it quits with the albedo here, I just think its better to dial in the color zones by hand painting at the very very last moment of the whole process. It will be a lot easier to judge once the likeness is looking solid and the other textures in place. Hand painting color zones is pretty straight forward, use a scattering brush in your program of choice and paint mostly mid tones as you see them in your reference. In Michael Clark Duncan I notice a lot of darkness in the eye area, a lot of light yellows in his nose, his lips have strong red right in the crease but are lightish pink purple on the lower lip at its peak, darker near the edges and it has a light outline. I could talk more about him, but this is essentially the thought process you should have when painting the face. Analyze all this stuff from your ref and apply it. Dont go too heavy handed either, you want to retain detail from the baked maps. Oh and one last time, save this hand painting till the end, its not helpful before hand. You’ll likely go too heavy handed if you do it too soon and make him look like he’s wearing some crazy makeup or something.
Brads super secret trick: One thing I literally made up myself here that I thought made sense was integrating hairs better into the albedo. I did this as a final step after the hand painting. Once all hair fibers where in place I exported them filled with solid bright vertex colors (red for facial hair, green for peach fuzz, and blue for eyebrows). I also exported the head into marmoset. I then colored the head white and baked the hairs to the face with a tiny little push on the cage. The end result were little dots everywhere: exactly where the hair sits on the surface of the face. If you want to separate head hair from facial hair for instance just use the different colors for the vertex color bake and you can easily select based on id after the fact. But what I did is desaturate all the tiny dots and used it as a mask on a fill layer in painter, blured them slightly, gave them a mid range red color and multiplied those dots on top of the albedo. So now you have tiny color details where the hairs are on the face better integrating them. I also gave them a slight negative height as well which simulated a slight depression in the skin. Again, all super subtle stuff, but I think it helps on ultra closeup renders so it doesn’t look like you have floating hairs everywhere.
This leaves the two mysterious textures in my mind. Gloss and Specular. Do you add detail to gloss, do you add it to specular do you do it to both? Who knows! It’s a mystery!!! Haha. Well sort of, I can’t say the exact proper way to do it, again I landed on this based on my own tests. I would love someone to chime in here and tell me I’m wrong and this is the exact way to be physically accurate. But I am still waiting for this day to come so here it goes. :D
I noticed a lot of people using gloss very basic. So after lots of tests trying both, I decided the best method was to make the gloss more basic (WITHOUT MUCH CAVITY OR HEIGHT) and leave the cavity trickery to the specular map. Once I applied a cavity bake to the specular it was amazing how much better everything popped. 3d scan store does this as well I noticed, but it’s a bit more simplistic then my method. Below are my spec and gloss maps. I used 8k for everything but you should get the idea with lower res here. Note: The gloss map here is WITHOUT the sweat applied. That’s not something you probably want and will only confuse the matter if I show that one. If you saw the sweaty one there would be crazy white lines all over the place, haha.
Specular: Ok, so that’s the high level plan, lets dive deeper into the specular. PBR specular value for everything that is not metal or liquid should technically be dark grey 56x56x56 RGB always. The only exception I have found was skin. Again, I’m not a material programmer, but skin for some reason is different. So, wood, plastic, leather, cloth, paper etc. All things not metal, liquid or skin are 56x56x56 as a base (or .04 x .04 x .04) . This simplifies things because you establish a lot of the feel of your object by adjusting the gloss. In the case of skin its slightly darker then this 56x56x56 default. Its more like 42x42x42 (or .02 x .02 x.02). So use this as your starting point on the spec. Then leverage your height, cavity, and ao. Paint hairy areas darker like stubble and the top of the head. Using the height map is super cool, cause you can overlay it and add lightness to bumps and darkness to recesses. This is probably one of the things that makes your skin pop the most and look believable. Add some subtle cavity, and ao with multiply on both. And that’s pretty much it. The only hand painting on the spec that’s really necessary are in the hair areas mentioned above, the rest is blending and leveling bakes. You can look and see mine to get the idea of how to balance it all.
Gloss: Lastly is the gloss. A lot of people will tell you this is where you have the most artistry available. There is a pretty cool tutorial on it so I’ll point you to that. I like how he applied some wavy detail to his gloss, I did this very subtly on mine in the end to break stuff up slightly. https://marmoset.co/posts/creating-realistic-skin-toolbag-saurabh-jethani/
Please take that tutorial with a grain of salt, much of it still applies but its older now and is talking specifically about marmoset 3 not marmoset 4.
In that tutorial he makes a roughness map. I used gloss since I’m more familiar using gloss. But it’s the same thing really, roughness is just an inversion of gloss. So if you copy my map and invert it, there you go, its roughness now.
MOAR GLOSS: So more specifically, I applied a mid grey, then painted lighter oily zones of the face making the top of the head where the hair is especially oily along with the nose. Wetter areas around the eyes and nose get heavy white painted there as well. Subtle ao is applied and again leveraging the height map to overlay detail. This became my base gloss. Similarly to the Albedo I left it here and did a final pass on the gloss at the end. At that end stage, I just used my best judgment to paint larger areas brighter or darker depending how it was reading in marmoset, and I painted tiny details like moles and stuff more or less dark depending on how they appeared in my reference. And that’s it for the entire texture process! The skin for the body was rinse and repeat, then the other elements come down to basic pbr texturing. No surprises with that stuff.
Final Note: End of the day, texutures and materials are always going to be very important when creating realistic characters. There are base values you can use as a starting place to guide you and if you follow these steps you should get good results in marmoset 4 specifically (from what I gathered). However… the real trick is the high poly sculpt. That is most important of all by far. So if you have a really good sculpt as a starting point, and you follow some simple methods like I mention here you will be in a great spot. If you don’t have this, then you’re pretty much doomed. Lol. I don’t know how else to put it. So pour as much effort as you can into those high poly sculpts. Get scan references if possible so you have a delta to use as a reference and go from there. I hope this is helpful to someone out there. If not it’ll be helpful to my forgetful future self XD. Please leave comments or suggestion or anything else that comes to mind in the comments section below. I would love to start an open dialogue. Cheers!
