SSS shaders

135

Comments

  • SertorialSertorial Posts: 743
    edited December 1969

    Szark said:
    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.

    Thank you! :)

  • GeddGedd Posts: 2,444
    edited December 1969

    Thank you Szark and Richard for the information about groups, I hadn't understood this yet either :)

  • wancowwancow Posts: 2,708
    edited December 1969

    Developing my SSS Settings... this one has 100%SSS with 40% Diffuse... I know that does not add up to 100%... I'm working on developing the shaders I want to use for all my figures. I had to jack up the light intensity back to 100% for the Key and UE2, 50% fill and 200% Back and I added a Speclamp above and to the left of the camera. I'm going to have to do something about the hair. I was conversing with Jim-Zombie on DA and it occurred to me, that when we're talking about Specular and Reflection, you have to consider the surface before you add it into the mix. My thought is this: with skin, specular and reflection should go together, but NOT with Diffuse and SSS, as it's most often a function of moisture and/or oil on the surface of the skin, therefore it is not the same surface. The same would be true of Varnished wood. Metal, Opaque Plastic etc would, however, require that you have DIffuse, Spec and Reflection all be part of the same surface formula since those are hard surfaces with no subsurface. Cloth would be the same, with SSS added into the mix...

    Anyway, still trying...

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  • GeddGedd Posts: 2,444
    edited May 2013

    There's a simple answer to this. Bring it into a photo editing program and check out the histogram. If it's not getting blown out and it looks the way you want, it's fine. If trying to make a setup that works for a range of applications, set up test cases of the extremes and some random and run them through, checking visual and histo.

    I try to avoid shortcuts that are just off base whenever possible, such as adding ambient to things that wouldn't have ambient, but there is a point where we are working with approximations to start with, so fudging it almost comes with the territory to some extent. This goes for unbiased render engines also. HDRI is one big fudge for the fact that we don't have all of the light sources and bounce light we would irl.

    Post edited by Gedd on
  • wancowwancow Posts: 2,708
    edited December 1969

    We do have GI :) I have not the first clue how to read a histogram :)

  • GeddGedd Posts: 2,444
    edited December 1969

    Yes, but GI is a fudge for rl aspects that is impossible to take into account in a realistic manner.. all the surfaces, light sources... irl.

    As for histograms, they are easy.. if it's maxed out anywhere along the line, it's blown out. You could get a better explanation from doing a youtube search probably where they would demonstrate it.

  • TofusanTofusan Posts: 17
    edited December 1969

    With gamma correction on 4.5.2.40 beta, SSS seems to be beautifully rendered.

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  • mark128mark128 Posts: 880
    edited December 1969

    I recently purchased the Brialen character (http://www.daz3d.com/briallen). She comes with both std mats and mats using the UberSurface shader including settings for SSS. The comparison image below is the same character render in exactly the same lighting with the two different sets of material. The lighting was a custom arrangement of InaneGlory lights and was exactly the same for both renders.

    Now I did find and correct what I believe is a bug in the USS material settings for the face. The Subsurface color is white with a texture. On most body regions the mat is using a texture that looks like the diffusion texture with a lot of pink or red added to it. In the face the subsurface color texture is the specular strength texture, which is black and white. This seems to be true for the default skin as well as the makeup options. I corrected the subsurface color texture for the comparison below. It only makes a small difference. It makes the face look a little more pink.

    The first thing I noticed is the skin looks darker with the USS shader. I compared how the two shaders were set up.

    Diffusion: both seem to use the same texture. The std mats have diffuse strength at 100% and the diffuse color set to 232, 244, 248, just slightly bluish. The USS material has the diffuse strength at 90%, diffuse color at white and diffuse roughness at 1.00.

    Specular: The std mat has no specular texture, spec color at 211, 237, 239 (blueish), strength at 9.7% and glossiness of 68.3%. The USS material has a specular texture, a color of 203, 219, 255, strength of 15%, glossiness of 10%. The specular texture is pretty dark, so specular is confined to a few regions on the face.The USS mat has specular2 with same texture as specular, color 203, 219, 255, strength of 15%.

    Ambient: the std mat has ambient color of 255, 240, 239 (pinkish) and Ambient strength of 31.7%. The USS material has Ambient turned off.

    USS mat has Fresnel Strenght at 80%, Fallof 2.6, sharpness 83%.

    Velvet color 203, 219, 255, strength 25%, fallof 20

    Subsurface is Active: color uses a texture that looks like the diffusion texture with a lot of pink/reds added (this is after fixing bug in face material) and has color white, strength is 10% with a texture map that puts the subsurface effects mainly in the cheeks, refraction 1.3, Scale 1.7.

    Translucency is Active: color is white with a custom texture. It look kind of like a washed out version of diffusion texture. The strength is 25% with a different texture that looks very similar to the Subsurface strength texture, putting most of the effect in the cheeks.

    I really don't understand why all these settings are the way they are. The ambient is high in the Std shader, and I guess the bluish color in the diffusion is to correct for the pink color of the ambient.

    This skin uses strength maps that confine the subsurface and translucency effects to the cheeks.

    compare.jpg
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  • GeddGedd Posts: 2,444
    edited May 2013

    If you watch Omnifreaker's videos you will see where he talks about this in US2. I'm sure some of the same type of issues existed in US1 in that because the way the shader works with light, it will get darker and will need to be adjusted and is not a bug. Understand, when switching shaders just like switching render engines, things change and we have to adapt our item to that change. It isn't a free, slap it on and it works kind of thing. I think this thinking comes from the idea of people doing the ctl click thing, that it doesn't 'replace' materials. But that's just it, it's just 'not replacing materials'... it's not automatically adjusting settings that are there that weren't in the previous shader. It still needs to be tweaked. Some people are fine with what the get without going to the trouble of tweaking it, some tweak it without thinking about it...

    Post edited by Gedd on
  • GeddGedd Posts: 2,444
    edited May 2013

    On the question of Specularity and UE. I just saw a video posted earlier in one of these thread that covered this and unfortunately hadn't processed what he was saying fully. Basically he was showing, with examples, how UE does not provide specularity, or at least not near the level of specularity one would get from a directional lighting source, so that was exactly why one would want to add a specular only camera. That is, UE is basically an omnidirectional light source. It provides AO but not very strong directional lighting. With any omnidirectional lighting one would want to add back the specular lighting at times one doesn't see from the omnidirectional lighting. Now, if using omnidirectional lighting to mimic rl type settings, one wouldn't be getting specular anyways from that type of lighting so ... it comes down to artistic enhancing of that aspect in the end anyways (which we do in photography through various means.)

    The whole point of a specular only camera is to enhance specular in a particular way we want that the lighting doesn't provide. It's that simple, no math need apply. The thing to keep in mind is, any time we are doing this type of enhancement we want to err on the side of subtle usually. If someone sees our picture and says 'there's too much specular,' I can assure you, they didn't do any math, they just saw it was too much.

    Post edited by Gedd on
  • SzarkSzark Posts: 8,759
    edited December 1969

    Sertorial I haven't forgotten just not had the time to sit down and dig out my eyes settings. I will try today.

    Mark128
    Why are you using Fresnel on Skin?
    Ambient is a cheep way of lighting up shadows etc, I and many people I know that use these shaders do not use any Ambient of surfaces prefering to let the light do that job.
    Transluceny is a fake too and as Omnifreaker said himself for skin you don't need to use it.

    Diffuse colour. Putting the diffuse to White will increase the red that is in the skin texture, hence way it was blusih origianally and why it is more pink. The red we try to inject with SSS so my advice is drop the red in the diffuse colour channel.
    IOR for skin is 1.39 - 1.14
    SSS scale try 0.50

    There is not right or wrong way to set all this up just good and bad results.

    For anyone that really wants to learn this stuff then learn about the real thing. It is all out there. All IOR values are out there too for all body parts. This setting up these shaders is a balance between each channel, many subtle but the trick is not to over do colours, keep them staturated as much as you can. Always set up you skin in white light.

    And have you noticed the ON/OFF toggle for each channel. Good way to test things is to remove the skin maps and then turn off all the channel barring one and test render, turn that off, turn another on and test render. This way you will see the effect without the other effects getting in the way. Also when testing each channel change the colour to a very extreme bright colour this will make the effect more visable.

  • GeddGedd Posts: 2,444
    edited May 2013

    Just watched Omnifreaker's video on UE2 yesterday, he mentioned using Fresnel instead of something like translucency, to get the ear type thing. That is, if one wants translucency type of effect on something thick like skin they would use Fresnel is what I gathered from it. Translucency being for thin items 'like paper or leaves' was his quote iirc.

    Post edited by Gedd on
  • SzarkSzark Posts: 8,759
    edited December 1969

    Gedd said:
    On the question of Specularity and UE. I just saw a video posted earlier in one of these thread that covered this and unfortunately hadn't processed what he was saying fully. Basically he was showing, with examples, how UE does not provide specularity, or at least not near the level of specularity one would get from a directional lighting source, so that was exactly why one would want to add a specular only camera. That is, UE is basically an omnidirectional light source. It provides AO but not very strong directional lighting. With any omnidirectional lighting one would want to add back the specular lighting at times one doesn't see from the omnidirectional lighting. Now, if using omnidirectional lighting to mimic rl type settings, one wouldn't be getting specular anyways from that type of lighting so ... it comes down to artistic enhancing of that aspect in the end anyways (which we do in photography through various means.)

    The whole point of a specular only camera is to enhance specular in a particular way we want that the lighting doesn't provide. It's that simple, no math need apply. The thing to keep in mind is, any time we are doing this type of enhancement we want to err on the side of subtle usually. If someone sees our picture and says 'there's too much specular,' I can assure you, they didn't do any math, they just saw it was too much.

    Yes that is true UE2 does not give good spec or directional shadows. I have never seen a HDRI that will produce directional shadows light the sun does hence why all the HDRI set in the store have distant lights included. But UE2 does and can blow out specualar highlights that the additional light makes this is why I also agree using all the lighting set to Diffuse light only and use one Specular only light can give more control over specular highlights.

  • SzarkSzark Posts: 8,759
    edited December 1969

    Gedd said:
    Just watched Omnifreaker's video on UE2 yesterday, he mentioned using Fresnel instead of something like translucency, to get the ear type thing. That is, if one wants translucency type of effect on something thick like skin they would use Fresnel is what I gathered from it. Translucency being for thin items 'like paper or leaves' was his quote iirc.
    I haven't seen the vid Gedd, throw us the link please. :)

  • GeddGedd Posts: 2,444
    edited December 1969

    Actually just put up a post here which has a few links in it, that one included.

  • GeddGedd Posts: 2,444
    edited May 2013

    Szark said:
    using all the lighting set to Diffuse light only and use one Specular only light can give more control over specular highlights.

    For me, I'd set up my basic lights, UE, directional, point etc.. whatever I'm using in the scene, then add spec only as needed. If spec was getting blown out I would then start turning spec off in the other lights. Not that this is a better work flow, just one that works for me. Whether you start at the right and go left, or start at the left and go right.. you reach the same point ;)

    Post edited by Gedd on
  • mark128mark128 Posts: 880
    edited December 1969

    Szark said:
    Sertorial I haven't forgotten just not had the time to sit down and dig out my eyes settings. I will try today.

    Mark128
    Why are you using Fresnel on Skin?
    Ambient is a cheep way of lighting up shadows etc, I and many people I know that use these shaders do not use any Ambient of surfaces prefering to let the light do that job.
    Transluceny is a fake too and as Omnifreaker said himself for skin you don't need to use it.

    Diffuse colour. Putting the diffuse to White will increase the red that is in the skin texture, hence way it was blusih origianally and why it is more pink. The red we try to inject with SSS so my advice is drop the red in the diffuse colour channel.
    IOR for skin is 1.39 - 1.14
    SSS scale try 0.50

    There is not right or wrong way to set all this up just good and bad results.

    For anyone that really wants to learn this stuff then learn about the real thing. It is all out there. All IOR values are out there too for all body parts. This setting up these shaders is a balance between each channel, many subtle but the trick is not to over do colours, keep them staturated as much as you can. Always set up you skin in white light.

    And have you noticed the ON/OFF toggle for each channel. Good way to test things is to remove the skin maps and then turn off all the channel barring one and test render, turn that off, turn another on and test render. This way you will see the effect without the other effects getting in the way. Also when testing each channel change the colour to a very extreme bright colour this will make the effect more visable.

    The Std and USS settings were all vendor supplied. The Briallen character comes with two sets of skin materials. One using the Std shader and one using the USS shader (although it is labeled HSS material). The only change I made was to correct what I thought was a mistake in the USS shader for the face. The subsurface color for the face used a black and white 'S' texture that was also used as the specular strength texture. All the other skin regions other than the face used a 'SD' texture that looked like the diffuse texture with more red or pink in it. There was a 'SD' texture for the face too, so I changed it.

    From reading the UberSurface doc I think Fresnel only effects reflection in UberSurface and reflection was turned off. I think leaving Fresnel on should have no effect. This is not true in UberSurface2, where Fresnel also effects specular.

    I was really surprised at the amount of ambient being used in the std mat. I have seen small amounts used on lots of skin mats, but I don't think I have seen this much before (color of 255, 240, 239, strength of 31.7%) There is no ambient in the USS mats. I think this is a big reason the USS skin looks darker.

    I think this vendor has set the subsurface to be weak. The strength is 10% and they have a black and white texture in the subsurface strength that only has white or grey areas on the nose, cheeks and a strip between lips and chin.

    The vendor seems to have chosen to use translucency more than subsurface. There is a texture in the Translucency color which is a pale version of the diffusion texture. The translucency strength is 25% but with the same control texture as the subsurface (nose, cheeks, between lips and chin).

    What is the rational for only using subsurface/translucency on some parts of the skin and not others?

  • GeddGedd Posts: 2,444
    edited May 2013

    Deleted, was a repeat.

    Post edited by Gedd on
  • mark128mark128 Posts: 880
    edited December 1969

    mark128 said:

    The first thing I noticed is the skin looks darker with the USS shader.

    I have confirmed that the USS skin looks darker because it does not use ambient like the std shader does.

    In this image I am using a single UberArea light plane which is camera left. This shows renders with the Std material, the Std material with all skin ambient set to zero and the diffuse color changed to white, the USS material. In the render with the Std material you can clearly see on the side of the head which is in the shadows, how much the ambient light is contributing. There are some differences in the specular hightlights between the Std No Ambient and the USS renders, but this is not surprising since the specular sections of the shaders are setup quite different.

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  • GeddGedd Posts: 2,444
    edited May 2013

    While they are not settings I would think of off the top, the results don't look bad.

    Post edited by Gedd on
  • mark128mark128 Posts: 880
    edited May 2013

    I spent a lot of time playing around with this texture using UberSurface and UberSurface2.

    The render below is with UberSurface2:

    Diffuse: strength 80%, color white.

    Specular: strength 8%, color white, glossiness 15%, sharpness 0%.

    Fresnel: off

    Ambient: off

    Reflection: off

    Velvet: off

    Subsurface: on, color white, strength 20%, refraction 1.3, scale 1, back scatter boost 2, Scatter Color 139, 10, 0, Scatter strength 1.98, Absorption Color 244, 128, 0, Absorption Strength 0.70 (this is skin3 preset for uberSurface2).

    Translucency: off

    Specular2: off

    Edit: replaced the pic, better lighting.

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    Post edited by mark128 on
  • SertorialSertorial Posts: 743
    edited May 2013

    mark128 said:
    The Briallen character comes with two sets of skin materials. One using the Std shader and one using the USS shader (although it is labeled HSS material).
    What's the difference between the HSS shader and the USS shader? (both by Omnifreaker). BTW I really wish he'd make more videos. He's only made like three and he's got loads of complicated products that need explaining!

    Sertorial I haven't forgotten just not had the time to sit down and dig out my eyes settings. I will try today.

    Thanks :)

    Post edited by Sertorial on
  • mark128mark128 Posts: 880
    edited December 1969

    Sertorial said:
    mark128 said:
    The Briallen character comes with two sets of skin materials. One using the Std shader and one using the USS shader (although it is labeled HSS material).

    What's the difference between the HSS shader and the USS shader? (both by Omnifreaker). BTW I really wish he'd make more videos. He's only made like three and he's got loads of complicated products that need explaining!

    UberSurface is an enhancement of the HumanSurface shader. Both are included free now with DAZ Studio. This link outlines the enhancements: http://www.omnifreaker.com/index.php?title=UberSurface

  • SzarkSzark Posts: 8,759
    edited December 1969

    Sertorial said:

    Szark said:
    Sertorial I haven't forgotten just not had the time to sit down and dig out my eyes settings. I will try today.

    Thanks :)

    I must apologise Sertorial for not getting the info. The problem is I set a render off on Firday evening and it is only 25% done..yep 4 whole days and counting. well 5 really and I can't get to my Uber Surface 2 testing scene with the settings in until the render finsihes. I am hoping once it gets past the transmapped area the render should get faster. As soon as it does finish the first thing i will do is to dig out the info for you. I am really sorry about this.

  • SzarkSzark Posts: 8,759
    edited December 1969

    Ok Eyes.

    Here are my Cornea settings http://www.daz3d.com/forums/discussion/10835/P105/#270994

    As for the other parts like Lacrimal and Sclera there have the same IOR and skin, 1.39 and for Genesis I would use the same Specular setting as the Cornea as unlike the Gen 4 figure Geneisis doesn't have a EyeSurface materail zone which we used to use for Reflections.

    Iris and Pupil need no SSS just Specular 1 will do, try the Cornea Spec settings.

    BUT Spec settings are dependent on your lighting so you do need to test and adjust as need.

    In fact that goes with all surafces no matter what shader or textures you use for any material. There is no avoiding testing if you wnat good results.

    Also there have been a few threads lately about SSS Scale and Shading Rates and I have tested them and they do work.

    SSS Scale 0.10
    SSS Shading rate 1 or 2. Higher SSS shading rates or for Translucent materials like thin things like paper etc.

    Also when setting up Spec 2 you will need to turn off SPec 1 and test render Spec 2 settings, then once you are happy turn spec 1 back on and test again.

  • SertorialSertorial Posts: 743
    edited December 1969

    Szark said:
    Ok Eyes.

    Here are my Cornea settings http://www.daz3d.com/forums/discussion/10835/P105/#270994

    As for the other parts like Lacrimal and Sclera there have the same IOR and skin, 1.39 and for Genesis I would use the same Specular setting as the Cornea as unlike the Gen 4 figure Geneisis doesn't have a EyeSurface materail zone which we used to use for Reflections.

    Iris and Pupil need no SSS just Specular 1 will do, try the Cornea Spec settings.

    BUT Spec settings are dependent on your lighting so you do need to test and adjust as need.

    In fact that goes with all surafces no matter what shader or textures you use for any material. There is no avoiding testing if you wnat good results.

    Also there have been a few threads lately about SSS Scale and Shading Rates and I have tested them and they do work.

    SSS Scale 0.10
    SSS Shading rate 1 or 2. Higher SSS shading rates or for Translucent materials like thin things like paper etc.

    Also when setting up Spec 2 you will need to turn off SPec 1 and test render Spec 2 settings, then once you are happy turn spec 1 back on and test again.

    Thanks so much for this. And please don't worry about the delay. Really not a problem. I just appreciate all the help I can get (and that's loads on this fine forum :) )

    I think what i plan to do is set up all my US settings on one figure then just copy and ctrl-paste them to any other figures I want. Unless there is some way to save a surface as a preset ?? Don't know. Would be handy if there were.

  • SzarkSzark Posts: 8,759
    edited December 1969

    You can remove all the maps and save a material preset and use CTRL when applying and choose to Ignore replacing maps.

    BUT there won't be one set of settings for different Skin textures...you have to treat each skin set separately. Though things like SSS settings will be the same and will give you a starting point.

  • SertorialSertorial Posts: 743
    edited May 2013

    Szark said:
    You can remove all the maps and save a material preset and use CTRL when applying and choose to Ignore replacing maps.

    BUT there won't be one set of settings for different Skin textures...you have to treat each skin set separately. Though things like SSS settings will be the same and will give you a starting point.

    So here is my image with the corneas done (not exactly sure which bit of the eye the cornea is, but...). First render is just with a UE2 and KH Park HDR map and the second render is with the ART_Andrea GYT light set (AOIBL)

    Why does it have those funny looking reflections tho? There's nothing else in the scene.. (unless maybe it's the HDR image I stuck on the UE2 light (KH Park)? Is that possible? Does that work like a background that could reflect in the eyes?)

    Dana_head_SSS_with_AOIBL_light_set.jpg
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    Post edited by Sertorial on
  • SzarkSzark Posts: 8,759
    edited May 2013

    It is a good start Sertorial. Keep at it.:)

    No the UE2 sphere won't reflect in the cornea and without any thing to reflect you will get some weird results.

    This is fixed either by using a reflection map or placing a plane with an image on behind the camera to one side so there is something to reflect. Or you could load a new Sphere and apply a map to that.

    I like doing both type of reflections, real and fake, it just depends on what the image is.

    Also I have found that reflection strength depends on the lighting. I have found using Distant lights etc you need to drop the reflection strength down more and if using Area lights then those settings should work fine.

    If you don't know what a cornea is Google it and on Wikipedia there is a break down of the eye showing which part is which. I must admit learning all this has taught me a lot about anatomy and latin names of muscles and various body parts.

    The Scalea (eye whites) are on the blue side in your image, I like to go for a very light grey to white.

    You maybe interested in this product http://www.daz3d.com/actual-eyes-3 for Genesis eyes. It has great textures, settings and reflection maps as shown below in a WIP I am doing at the moment, testing some Uber Surface 2 settings I have recently learnt. Here I am using fake reflections on the cornea using a reflection map. I need to adjust the positioning of the area lights too, to avoid the dark shadow line going down the the face.

    The skin texture set is http://www.daz3d.com/v5-elite-skin-texture-valerie with SSS strength maps from http://www.daz3d.com/interjection-surface-injections-for-daz-studio. Just the maps not the settings. I dont like the coloured SSS strength maps that come with the texture set as they won't work in Uber Surface 2 as the SSS scatter colour doesn't accept maps.

    I had to lower the red channel of the Diffuse colour a little to compensate for the red coming from the SSS.

    What I did to set this up was to remove all the maps and set the diffuse colour to a mid gray then turned all the other channels off baring one, say Spec 1 and did a test render, adjust and test again. The I would turn that off and test Spec 2, adjust and render. Once I was happy I turned my attention to Fresnel, Bump then SSS all the time turning off the previous channel. Once I was happy I manually loaded the texture maps back inand turned on the channels and test rendered.

    This was lit with two Area lights and UE2 (sotfbox HDRI preset) set to Indirect Lighting with Soft shadows on High preset but changied the UE2 Shading Rate down to 1 from 8. This is needed when using IDL, sometimes you may need to go as low as 0.10 but it does depend on what you are rendering. It took me 3 hours to render at a little larger (I had to crop the bare breasts off to post here). I don't have a very good machine either.

    I have still got a lot more adjusting to do like on the ears, like increasing back scatter boost or increasing the IDL strength in UE2 as I had it on 75% which is ok for Distant and spots but not for Area lighting.

    I also removed the spec maps completely.

    When I am done I can save the settings and send them to anyone who wants them to look over. Obviously I can't send the maps with them as that would be breaking the EULA. ;) But at least you can see what settings I used.

    Anymore in the scene and it will crash so I am glad I could get this done without DS4.5 crashing.

    Advanced render settings at default apart from Shading Rate at 0.10.

    Hope this helps.

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    Post edited by Szark on
  • SzarkSzark Posts: 8,759
    edited December 1969

    PS that second image is so much better, nice. :)

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