My Corona SSS playground

[plopalou]

maru: Sure. Here you go.



Both materials have 2 material blends.

The left one has normal maps disabled and blend amount is 1,0
The right one has normal maps enabled and blend amount is 1,0

I also noticed that if you disable the normal map from the base material the bug disappears. It doesn't matter if you add more blend materials with normal maps if you do so.

edit. typos and clarification

[maru]

Thanks! I'm not sure if it's a bug or something expected, but it looks wrong, so I will log it.

[plopalou]

maru: Ok thanks!

Here are some new tests. Added a few props just to see how the SSS works with different materials. You can see some white haloing around the eyes that comes from the translucency color. You can fix this by creating an additional color map... but it looks a bit weird since it darkens the scattering around the eyes. Probably a dedicated skin shader would work better.

I tried some hair testing with Ornatrix demo version. The hair looks much better when you can control tip and root color, width, possibility to create curly hair etc. After that going back to the hair&fur modifier feels like it's traveling back to the stone age.

I also tried adding some additional fill lights that Juraj suggested, but I couldn't make my renders look any better. Most of the renders are done with noemotionHDRi.

[plopalou]

selant: Sorry I forgot to help you with the skin shader. Here you go.

Diffuse: Level should be around 0,6-0,8. A texture in the color slot. You can also try to desature the texture a bit.
Translucency: Level. 0,7-0,9. Don't go any higher than 0,9 or the skin will look like paper thin wax. You can also create an additional texture for the level value so that the scattering isn't uniform. I experimented with AO bake + diffuse for that, but I didn't find it that to be that useful. I didn't use it for the renders above. Also you could create a very high contrast image to simulate dry, dead skin particles in the cheek and forehead area if you aim for super realistic skin. I would use a CoronaBlendMtl + mask for that though.

IOR: Around 1,2-1,33. Higher values give you too metallic reflections. If you want to have a peach fuzz type shading you can go even lower values, but I'd just create a hair layer for that effect.
Glossiness: Optimally you should have 2 specular layers. Use CoronaMaterialBlend for that. The broad spec value should be around 0,4 and the narrow about 0,6. Use a texture map for the values. If you want exact values you can use a CoronaMix + CoronaColor and multiply / screen your texture on top of it.

Absorption: Color. A neutral value around 125,125,125. If you want a stronger deep back scattering on the ears use reddish color 73,13,13 Distance: 0,15cm~ make sure that your head is in real world scale.
Scattering: Color. Put your diffuse texture here.

I've used these values with the Emily head except I only have 1 specular layer, because I'm getting weird dark spots from the normal map. I'm not sure what's wrong, but I'm sure it will be sorted out.

Try to experiment and have fun. :)

edit. typos + updated absorption values

[plopalou]

Another batch of tests... maybe the final ones I guess. I'm still not that happy with the results. Especially with the hair max feels dated (hair and fur hasn't been updated in ages?) and I guess the only way to get decent renders is to switch to Yeti or Ornatrix, Hairfarm.

I feel like I really need a dedicated skin shader or use more color texture maps to get better, realistic results. Anyway 100% realism isn't my cup of tea and I have to move on to more interesting projects. :)

[ikercito]

Congrats on your work. Human characters are probably the toughest thing.. I've tried it many times and it's an enormous task that seems like never ends. I'd say you're halfway across the Uncanny Valley still, but nevertheless it's a great work and you've shared some interesting tips and findings. Thanks!

[plopalou]

ikercito: Thanks! I'm glad that you find my stuff helpful. :)

The SSS component works very good as it is and gets you reasonable close to a realistic skin, but there is one annoying feature that keeps me getting the results that I want. The translucency / absorption color is very prominent where the geometry turns ie. the sides of a box or in case of a head the eye sockets, ears the tip of the nose. Also everything that penetrates the geometry will bleed according to the translucency / absorption color.

Here is an example with a teapot. The white balls are supposed to be eyes.



The only way to fix this afaik is to copy the diffuse color to translucency color and tweak the output. You can't see the bleeding with white light skin, but with dark skin it is problematic.

edit.

Here is an example with a real head. More sampling helps with the bleeding.



Translucency color is white.
Absorption is about 125,125,125



Diffuse color copied to translucency with output tweaks

[machmirdenlukas]

wow
great thread.
Keep on ...coronargasmic.
nice!
cheerz rob

[plopalou]

machmirdenlukas: Thanks for visiting! I'm glad you like them. :)

Here are some new render tests... It's an old model which I didn't finish few years back and the quality isn't that great. These are just quick SSS tests so don't kill me! :( I wanted to see how the shader looks in different lighting environments. I could maybe release this model for free if anyone is interested to try it out. The original creature concept is done by Jordu Schell. The color grading is done with 3Dluts.

The mapping in the shirt is just a quick auto UV from zbrush and the pattern isn't aligned properly.

The lighting is done with portals, CoronaLightMtl with HDR mapped to them.

[romullus]

Woha, that one is really nice looking creature. Good job!

[maru]

Damn, this guy is scary!
How did you use portals here? I cannot imagine it. Is there some modeled environment involved?

[steyin]

Now you are thinking with portals

[Noah45]

I would have suspected that guy would have some piercings. To show how tough he is. Certainly, he would have been picked on; for wearing that plaid shirt.

Crazy nice studies!

[plopalou]

Thank you everyone for the nice comments!

romullus: Thanks! This model is about 3 years old and I think I could have pushed to quality even further, but I felt It would take too much time and I have so many things to sculpt. :)

maru: Actually I used only portal with the last render where the head is close to a window. Everything else is done with planes + CoronaLightMTL with a HDRi image applied to them. I've found that it gives very nice results with the SSS and the light looks more "natural". I don't know if this method is the right way to use the material? :)

Noah45: I've noticed that I have added a nose ring to almost every character I've modeled so I didn't wanna repeat myself too much. :)

Here are quick renders with the penguin model I'm working on. I want to try out something simple, stylistic with the materials. I'm not aiming 100% realistic stuff. I'm trying to find a good and fast way to get everything exported from Zbrush to 3dsmax + render them with Corona. Sorry about the crappy renders... still a lot things to do.

Currently rendering hair as geometry gets quite slow when you crank up the hair count. It isn't perfect, but it's better than using shadow maps + different render passes with MR.

[plopalou]

adobelk: Thanks man! I really appreciate it!

Sorry for the lack of updates, but I've been busy with regular 2d mobile stuff. Today I created a backdrop for the penguin model. Basically its just some random modular building assets work that I did few years ago. Since it's blurred the low game res textures work relatively well. :) Also I have already posed the penguin in Zbrush, but re-importing and assigning materials will require some work still. I'm planning to pose Harley (the sculpt below) with penguin.

The viking model isn't going anywhere *sigh* unfortunately... so many unfinished projects. I have so many cool things to render and sculpt, but so little time. :(



Also I've been sculpting more super heroes on my lunch breaks + weekends. I did some minor face lift for Harley. Everything is still WIP. I hope I will get some time to pose and render these aswell. Just some screen caps from Zbrush for now (sorry this is not Corona related).



The joker sculpt is based on my friend Javier Burgos' work. I hope you like them!