My Corona SSS playground

[plopalou]

Small update:



Looks like the volumetrics shader doesn't calculate normal maps properly. I'm getting weird black spots on the skin.

[maru]

Looks like the volumetrics shader doesn't calculate normal maps properly. I'm getting weird black spots on the skin.

Can you mark the places in the image?
Are you using "single bounce only" option?
Can you show your material setup where this happens?

[plopalou]

Thanks for the quick reply Maru. I'll try to some additional tests to pin point out where it happens so it isn't just wild guesses ex. disable the diffuse / gloss / spec layers. I'm not using single bounce. I first thought that it was because of a body hair layer that I previously did some tests on. On the image that posted it happens on the chest and arm pit areas. Normal map was my first guess, because its strongest on those areas.

[plopalou]

This is what I wanna try out next with Corona. I hope I can this viking crap project asap. I really wanna render more simple cartoony stuff :) These are just SShots / renders from Zbrush.





The penguin design is based on a sketch done by my friend Javier Burgos.

[plopalou]

I've been mostly spending my time in Zbrush and finishing up the accessories on the viking model. Actually everything is more or less done in the modeling / UV depart and next I have to take it substance painter for textures... in the meanwhile here are quick renders of the Eisko scan.





The SSS shader is great, but it's quite hard to control. The most annoying part is the white halo that comes from the translucency component. Everything that penetrates the head geometry creates this effect ex. a wetness geometry around the eyes. I've tried to mask it with an additional color correction layer, but you can still see it under the eyes. You can also try to copy the diffuse to the translucency color and it fixes the issue, but I'm not sure if it's the correct way of using the shader.

maru: There is a possible bug with the translucency + normal maps and CoronaLayeredMtl and it's probably causing the darkness in the skin. If you use a material with translucency fraction of 1,0 and some Absorption and Scattering + normal map and try to blend it with another material you will get dark artifacts from the normal map.

Create a CoronaLayeredMtl and copy the main material to a layered slot (0) and set the blending amount to 10% (doesn't matter how much the blend amount is). If you disable the normal map the artifacts disappear. I'm quite sure it's the normal map whats causing the effect. I can do a proper bug report if you want + screen shots. This thread is probably not the right place for it. :) It's quite annoying since I can't create a secondary spec for the skin material currently. :(

[plopalou]

Another test from yesterday. The data is from digital emily project.



The hair is... umm... yeah. :)

[romullus]

Man, your models and textures are great, but lighting is plain awful. And most of your pictures are way too underexposed. You should improve that and i'm pretty sure, your topic will draw a lot more attention then.

[selant]

yes i agree with romullus, your textures and models are perfect..
can you share the last skin general details of the texture ? did you use sss, etc.. i will be very happy to learn! Keep sharing them

[plopalou]

romullus: Agreed. I'll try to focus more on quality rather than quantity. :) Especially those last few renders I posted look terrible. I'm currently just chilling around and testing how the SSS shader works with HDR mapped environment. I'm not too serious with my rendering work.  :) I'm not having any luck getting good renders with corona lights... the scattering looks so weak, waxy. Hmpf.
selant: I'll happily help you with the SSS shader. I'll probably have time next to write you something.

[Juraj]

Are you using good HDRi ? Judging from the exposure difference between background and model, and overall lack of any ligh direction, it almost looks like you use LDR instead.

[plopalou]

Juraj_Talcik: I'm using HDRs from noevermotionhdrs.net. They should be ok right? I love your work. :) Thank you for visiting my thread. I really appreciate it!

Here are some better renders with better contrast + lighting from last week. The render times are about 30-60min. I added some chromatic aberration in photoshop + saturation. Other than that they only have some basic exposure tweaks. I've also tried to experiment rendering hair... I hope I can post those soonish. The shader now has only one specular layer (broad) since sometimes I'm getting weird errors with the normal maps and CoronaLayeredMtl.

[maru]

I'm using HDRs from noevermotionhdrs.net

Are you sure this is the right address? ;)

[Juraj]

They should be ok right?

They're ok...but they're not really "true" HDRi. They're pretty clamped, intentionally, they use them with additional key-lights. NoEmotion are the very best guys out there, but they're also old-school and have different methods :- )

If you want to use ONLY HDRi, and also have strong lighting from it, not only ambient, you need to use different. There are many cheap and high-end sources.

Here is one absolutely bomb, 10 euros for non-commercial, and it includes 60 different HDRis. All wide-range.

http://www.panocapture.com/product/general-hdri-collection/

I'm using HDRs from noevermotionhdrs.net

Are you sure this is the right address? ;)

:- D Sounds like a good rule to work by.

[plopalou]

maru: Heh... That typo was ehhm... a freudian slip i guess? Don't tell anyone :)

With mental ray I used HDRIs just to get reflections + indirect lighting. The main light source was always a photometric light(s) + skylight, rayswitchers, background blur, overrides etc... I hated doing it.

I've noticed that most of the HDRIs from ahem.. noemotion :) give very soft ambient light with little or no shadows. I'll try adding an additional corona key-light and see how it looks. Of course it takes time to set it up right so that light has correct light intensity, position so that it matches the HDRi. The other reason I haven't used them because they don't look that good with SSS. I can't clearly pin point what's wrong with them, but the scattering looks artificial, waxy always when I add them. Should I use the shadowcatcher illuminator option with them?

Thanks for the tip on the panocapture HDRi. I'll definately test out those.

I'll post some new tests from yesterday later today.

Here is a render of the glitch I'm getting with NormalMaps and CoronaLayeredMtl that I explained earlier.

[maru]

Could you provide me with a sample scene where this bug appears? It could be a teapot + some random normal map, or even empty normal map and I would load something myself.