Digital Art Zone

 
   
4 of 9
4
SSS shaders
Posted: 03 April 2013 01:35 PM   [ Ignore ]   [ # 46 ]
Addict
Avatar
RankRankRankRank
Total Posts:  8123
Joined  2009-05-14

This will only happen if SSS is turned on so if a surface doesn’t have SSS ON then it doesn’t need a Group. Yes this only happens for this one channel. It is an economy measure

 Signature 

Pete

Somethings to Consider when starting to learn CG

My Gallery

My Render Thread and Tutorials

Proud member of the Bald Wizards Club and Co-operative

Profile
 
 
Posted: 03 April 2013 01:55 PM   [ Ignore ]   [ # 47 ]
Active Member
Avatar
RankRank
Total Posts:  670
Joined  2013-01-27
Szark - 03 April 2013 01:35 PM

This will only happen if SSS is turned on so if a surface doesn’t have SSS ON then it doesn’t need a Group. Yes this only happens for this one channel. It is an economy measure

when you say a surface, are you meaning like a single tab (eg skin hip)?

I don’t think I turned SSS on for her eyes anyway, but I’ll check

Profile
 
 
Posted: 03 April 2013 01:57 PM   [ Ignore ]   [ # 48 ]
Addict
Avatar
RankRankRankRank
Total Posts:  8123
Joined  2009-05-14

Yes sorry that is correct.

If SSS isn’t turned for the Eyes then it will be something else casuing the freakiness. smile

 Signature 

Pete

Somethings to Consider when starting to learn CG

My Gallery

My Render Thread and Tutorials

Proud member of the Bald Wizards Club and Co-operative

Profile
 
 
Posted: 03 April 2013 03:37 PM   [ Ignore ]   [ # 49 ]
Addict
Avatar
RankRankRankRank
Total Posts:  2947
Joined  2009-02-24

If that’s true, then how does 3DL handle conflicting values? For example, if I have three surfaces each with different SSS values but sharing the same group, which of the three values will be used? I’d always assumed that grouping didn’t change the values used but merely changed what it considered as a single surface, so that light could effectively pass into one material zone and exit via another as long as it’s part of the same SSS grouping.

 Signature 

Find me on DeviantArt
Download my free IBL presets for Luxus
Re-upload of Cresent’s awesome pwToon shaders
Create your own Smart Content

Profile
 
 
Posted: 03 April 2013 03:41 PM   [ Ignore ]   [ # 50 ]
Administrator
Avatar
RankRankRankRank
Total Posts:  14739
Joined  2003-10-09

The Group setting is sued to separate materials that shouldn’t interact - the teeth are separate from the skin and no matter how strong the light it shouldn’t scatter through the skin and out of the teeth, or vice versa, so they have separate groups. If you have contiguous materials, such as most of the skin surfaces, then they should belong to the same group so that scattering can cross the material boundaries. Generally all materials in a single group will have the same settings, other than maps, but it isn’t necessary.

 Signature 

DAZ Studio Frequently Asked Questions

Index of free DAZ Studio scripts and plugins list

Profile
 
 
Posted: 03 April 2013 04:14 PM   [ Ignore ]   [ # 51 ]
Addict
Avatar
RankRankRankRank
Total Posts:  8123
Joined  2009-05-14

Thanks Richard you put it so much better than what was in my head. smile

This really does come in to play when setting up the ears (Head texture not the face) with more SSS (to simulate light shining through the ears) than the other parts of the same skin texture group. Same with Teeth being the Mouth group which includes Gums, Innermouth and Tongue which would have a different SSS Grouping than the Teeth. (But i only do this if the mouth is open. smile

 Signature 

Pete

Somethings to Consider when starting to learn CG

My Gallery

My Render Thread and Tutorials

Proud member of the Bald Wizards Club and Co-operative

Profile
 
 
Posted: 03 April 2013 04:42 PM   [ Ignore ]   [ # 52 ]
Addict
Avatar
RankRankRankRank
Total Posts:  2947
Joined  2009-02-24

So, I was on the right track then? I guess I must have picked up something from all that playing around after all :D

 Signature 

Find me on DeviantArt
Download my free IBL presets for Luxus
Re-upload of Cresent’s awesome pwToon shaders
Create your own Smart Content

Profile
 
 
Posted: 03 April 2013 05:22 PM   [ Ignore ]   [ # 53 ]
Active Member
Avatar
RankRank
Total Posts:  670
Joined  2013-01-27
Richard Haseltine - 03 April 2013 03:41 PM

The Group setting is sued to separate materials that shouldn’t interact - the teeth are separate from the skin and no matter how strong the light it shouldn’t scatter through the skin and out of the teeth, or vice versa, so they have separate groups. If you have contiguous materials, such as most of the skin surfaces, then they should belong to the same group so that scattering can cross the material boundaries. Generally all materials in a single group will have the same settings, other than maps, but it isn’t necessary.

but why would you need the group thing? I don’t understand. You can set the SSS properties at different values just by highlighting that particular surface, surely? Just like you can highlight the arm and give it a different, say, glossiness from the leg? When you select a particular body part it goes orange in the shader window, then you dial up what you want. You can then select a different body part and select a different value?

Am I missing something here?

Profile
 
 
Posted: 04 April 2013 03:15 AM   [ Ignore ]   [ # 54 ]
Addict
Avatar
RankRankRankRank
Total Posts:  8123
Joined  2009-05-14

As I said earlier it is the way 3Delight calculates SSS when rendering. Sorry but if you need more understanding then I can’t help as we are getting into Geekiness and I don’t much Geekiness. LOL But i will go and have a look and see if I can find something that better explains it.

 Signature 

Pete

Somethings to Consider when starting to learn CG

My Gallery

My Render Thread and Tutorials

Proud member of the Bald Wizards Club and Co-operative

Profile
 
 
Posted: 04 April 2013 05:54 AM   [ Ignore ]   [ # 55 ]
Administrator
Avatar
RankRankRankRank
Total Posts:  14739
Joined  2003-10-09
Sertorial - 03 April 2013 05:22 PM
Richard Haseltine - 03 April 2013 03:41 PM

The Group setting is sued to separate materials that shouldn’t interact - the teeth are separate from the skin and no matter how strong the light it shouldn’t scatter through the skin and out of the teeth, or vice versa, so they have separate groups. If you have contiguous materials, such as most of the skin surfaces, then they should belong to the same group so that scattering can cross the material boundaries. Generally all materials in a single group will have the same settings, other than maps, but it isn’t necessary.

but why would you need the group thing? I don’t understand. You can set the SSS properties at different values just by highlighting that particular surface, surely? Just like you can highlight the arm and give it a different, say, glossiness from the leg? When you select a particular body part it goes orange in the shader window, then you dial up what you want. You can then select a different body part and select a different value?

Am I missing something here?

It’s not for different properties - it’s for declaring things to be separate, so that light that is scattered by one surface (say the skin of the face) doesn’t come out of another (say the teeth or the eyes).

 Signature 

DAZ Studio Frequently Asked Questions

Index of free DAZ Studio scripts and plugins list

Profile
 
 
Posted: 04 April 2013 11:03 AM   [ Ignore ]   [ # 56 ]
Active Member
Avatar
RankRank
Total Posts:  670
Joined  2013-01-27
Richard Haseltine - 04 April 2013 05:54 AM
Sertorial - 03 April 2013 05:22 PM
Richard Haseltine - 03 April 2013 03:41 PM

The Group setting is sued to separate materials that shouldn’t interact - the teeth are separate from the skin and no matter how strong the light it shouldn’t scatter through the skin and out of the teeth, or vice versa, so they have separate groups. If you have contiguous materials, such as most of the skin surfaces, then they should belong to the same group so that scattering can cross the material boundaries. Generally all materials in a single group will have the same settings, other than maps, but it isn’t necessary.

but why would you need the group thing? I don’t understand. You can set the SSS properties at different values just by highlighting that particular surface, surely? Just like you can highlight the arm and give it a different, say, glossiness from the leg? When you select a particular body part it goes orange in the shader window, then you dial up what you want. You can then select a different body part and select a different value?

Am I missing something here?

It’s not for different properties - it’s for declaring things to be separate, so that light that is scattered by one surface (say the skin of the face) doesn’t come out of another (say the teeth or the eyes).

umm… err… I half understand that. The bit about it not being for different properties at least makes sense (otherwise it would be redundant). But I am not sure I understand your second part (but maybe that’s because I dont really understand was SSS is).

Profile
 
 
Posted: 04 April 2013 11:09 AM   [ Ignore ]   [ # 57 ]
Addict
Avatar
RankRankRankRank
Total Posts:  8123
Joined  2009-05-14

SubSurfaceScattering is when light penetrates the skin and scatters back out, giving us Caucasians a pink appearance. Some light is scattered and some light is absorbed. UberSurface 2 as an added Absorption colour and strength settings included with the SSS channel which Uber Surface and HSS don’t have.

 Signature 

Pete

Somethings to Consider when starting to learn CG

My Gallery

My Render Thread and Tutorials

Proud member of the Bald Wizards Club and Co-operative

Profile
 
 
Posted: 04 April 2013 03:54 PM   [ Ignore ]   [ # 58 ]
Active Member
Avatar
RankRank
Total Posts:  670
Joined  2013-01-27
Szark - 04 April 2013 11:09 AM

SubSurfaceScattering is when light penetrates the skin and scatters back out, giving us Caucasians a pink appearance. Some light is scattered and some light is absorbed. UberSurface 2 as an added Absorption colour and strength settings included with the SSS channel which Uber Surface and HSS don’t have.

right. I think I get it now. So the grouping means light will only be scattered into similar type bits of flesh

Profile
 
 
Posted: 01 May 2013 04:22 PM   [ Ignore ]   [ # 59 ]
Active Member
Avatar
RankRank
Total Posts:  670
Joined  2013-01-27
Szark - 03 April 2013 08:19 AM

Diffuse Colour: Leave that for now we can change it later.

Diffuse Strength drop to 90 – 80%

Specular: In reality spec colour is always white; it is the surfaces properties that can give the spec colour so I generally use White. Well that is how I understand things. Some vendors use a light blue colour. It is up to you what colour to use.

Glossiness: About 30 – 40% should make a nice start

Spec Strength: 8 – 10%

Spec 2. I still don’t know what or why there is a Spec 2. But this is one of those setting that can only be set up right when you turn off Spec 1 and test the spec 2 only. When you have the desired effects then reengage Spec 1 and test.

Anisotropic: Not for skin. Metals and Glass etc.

Ambient: I never use Ambient on Skin…ever.

Reflection: Some folks use a Reflection with an Environment Map (HDRI) but I have never had much success with this. Given you skin is generally oily having reflection does make realistic sense. If you want to have real (raytraced) reflections at a very low setting expect a longer render.

Fresnel: Not on Skin but good for Eyes mainly the pupil.

Velvet: Colour well this is a personal choice but after some testing I found a colour similar to the skin colour best like a peach/brown, 20% strength and about 15% falloff

SSS

Colour I always start with a 128, 0, 0 red and adjust up or down if needed. Want more red SSS increase the red and vice versa. However if there is too much red burnt in the skin texture maps then injecting red here will make the skin appear more red. To counteract this drop the red channel in the diffuse colour.

Strength depends on a few things, like are you using SSS maps then 100% should do it. No SSS maps then 20 – 50 % might do it.

Refraction: This is a good one as most scientists can’t agree what the IOR of skin is as there are so many variables but a value of 1.39 – 1.41 should do.

Scale: is how thick the surface is before the SSS takes place. This is something else I need to test and we don’t really know what value this is. If it is the Daz Studio default then 1 = 1CM and our skin is so much thinner than that. I have been trying to find out. IMHO 4 is why too high if this is the case. But with anything like this I say just go with what works. LOL I generally use a value of 1 to 1.70 before someone got me thinking what the value is.

Group: Is for grouping any surface that has the same SSS properties this is so the render engine knows what SSS properties applies to which surfaces. I use SSS on Teeth and Eye whites which have different SSS settings so I make all the Skin group 0, Teeth group 1, Whites group 2 and so on. If you don’t do this the render engine will lump all SSS together and render the whites and teeth with the same SSS settings as the Skin.

Translucency: I never use for skin. The SSS should give use what we need.

Just got around to trying our your great guidelines, above. Here’s an example. But I have only applied UberSurface to the skin surfaces. Wasn’t sure what to do about her eyes and they look a bit ‘flat’ by comparison. Do I apply US to those too? If so, what settings should I use? (presumably not the same ones as for skin?)

 

Image Attachments
test.JPG
Profile
 
 
Posted: 02 May 2013 09:31 AM   [ Ignore ]   [ # 60 ]
Addict
Avatar
RankRankRankRank
Total Posts:  8123
Joined  2009-05-14

Sorry I did get a notification of a reply and forgot about it, my bad. I am a tad buyt at the moment…visitors due soon, well there are here now.

I will try to reply later.

 Signature 

Pete

Somethings to Consider when starting to learn CG

My Gallery

My Render Thread and Tutorials

Proud member of the Bald Wizards Club and Co-operative

Profile
 
 
   
4 of 9
4