IRAY Photorealism?

j cade

isidorekeeghan said:

Hi everyone, i wrote a guide on how to properly setup subsurface scattering in daz/iray, i tried to cover everything, i posted it here https://www.deviantart.com/dfggcxbbb You can also get it from the attached file Hope it helps you understand things better

 

 

giving it color will put blue lines where two surfacess join when rendering with spectral rendering ON,

 Have you figured a solution to the blue line bug? My skin is clear, my crops are watered, you can have my nonexistent firstborn etc.

 

... quickly tested it on a scene where I kn ew the blue line was. and there was no blue line with colorless transmitted color. this is pretty fornicating exciting

emoryahlberg

isidorekeeghan said:

emoryahlberg said:

isidorekeeghan said:

Hi everyone, i wrote a guide on how to properly setup subsurface scattering in daz/iray, i tried to cover everything, i posted it here https://www.deviantart.com/dfggcxbbb You can also get it from the attached file Hope it helps you understand things better

This is great work, isidorekeeghan!

Here's an example employing your technique. The first one is my own chromatic shader which I worked forever on, but ultimately grew frustrated because my character's skin color kept changing. I had NO IDEA you could change the base color values above 1.00, and that alters everything.

The second one is with your technique, and I think the SSS is beautiful. The only thing I noticed is now the inside of my character's mouth is glowing. Also, my SSS glow is yellowish when it should be red.

Any suggestion?

Old SSS

 

 

New SSS

 

 

Thanks, just change the sss color hue to more redish color like 28 or something ,sss color is different for every skin ,some people have red some orange some pink, and what do you mean by glow i dont understand, maybe send me a close up

 

I actually ended up changing the sss color hue AND increasing the SSS direction, and that seemed to make it perfect!

Thanks to you, I believe I may have rendered my most photoreal face ever:

 

The only snafu is the glowing mouth. Here's what I mean:

lilweep

isidorekeeghan said:

In the guide i also cover how to fix blue lines around seems so go check it out, final render example in attached file

thanks for guide; reading it now.

the first step might be a barrier to entry for people who dont know where to go (i.e., render settings) to adjust crush blacks and burn highlights.  Also "add zero in front of" should probably be "add zero after decimal".

i only mention this because i am very stupid and unironically got stuck for a moment on the "before we begin" stage.

RayDAnt

j cade said:

RayDAnt said:

j cade said:

RayDAnt said:

Masterstroke said:

Padone said:

@Leonides02 That's also my point exactly. A pbr skin shader must work in any light condition, otherwise it's a not a skin shader but just a "trick". Then the light setup has to be realistic itself of course. That is, forget about point lights for example that don't cast reflections and have no size.

Indeed it is hilarious that most acclaimed "realistic" method here is based on point lights.

might be true, but this means, that you can forget about "photorealism" with IRAY.

It's not possible. period!
Maybe ten IRAY versions later.

EDIT:
That said, Iray can produce nice renders for sure, but If you want photorealism, you're better off with VRAY, Octane or maybe Cycles.

See this article for 20 fine to extremely fine examples of what level of photorealism Iray itself was capable of more than ten versions ago (and a lot has changed for the better since then.) Keep in mind that when dealing with Iray in the context of Daz Studio, you are almost exclusively interacting with it from within the confines of Daz's own custom (oftentimes barebones) implementation of it. Specifically in the form of the Daz-authored UberShader and compatible 2nd/3rd party pre-packaged content.

 

 

While I agree with the sentiment, none of these renders seem to be Iray Most seem to be using Vray or Mental Ray

Nvidia bought Mental Ray from its original developer Mental Images in 2007, ported its core codebase to Nvidia proprietary Cuda code so as to make use of GPU acceleration, and then started offering it as an independent product called Iray starting in 2010.

 

Iray was shipped with mental ray for a while

Yes, because Iray started out as an experimental Cuda-based fork of Mental Ray that was made available to existing users of Mental Ray during early development stages since they were uniquely well placed to beta test it.

 

j cade said:

perhaps they share some code

They shared exactly the same core code as of 2007 or so. As already stated by me, much has changed under the hood for Iray since then. But not in a way that would make it less capable of giving photorealistic results than its predecessor (which is the context in which Mental Ray was presently brought up.)

 

j cade said:

mental ray also had a dedicated sss shader rather than using volumetrics

This sentence makes no sense. Volumetrics is a generic underlying render engine mechanism. Shaders are programmable bits of code that tell a rendering engine which of its supported generic underlying render engine mechanisms (like volumetrics) it should use in rendering specific aspects of a given image. You can have a "dedicated" SSS shader that tells the rendering engine to use only volumetrics. Or volumetrics plus other things. Or other things and no volumetrics at all. These aren't opposing factors.

 

j cade said:

To call  Mental ray an older version of Iray is very incorrect.

Yes, Iray is a fork of Mental Ray going on 10+ years now.

emoryahlberg

RayDAnt said:

 

 

j cade said:

To call  Mental ray an older version of Iray is very incorrect.

Yes, Iray is a fork of Mental Ray going on 10+ years now.

Why are you both arguing over this nonsense? Post some photoreal pictures or start a Mental Ray vs Iray thread. Sheesh.

RayDAnt

emoryahlberg said:

RayDAnt said:

 

 

j cade said:

To call  Mental ray an older version of Iray is very incorrect.

Yes, Iray is a fork of Mental Ray going on 10+ years now.

Why are you both arguing over this nonsense? Post some photoreal pictures or start a Mental Ray vs Iray thread. Sheesh.

Lol yeah, sorry. This is mostly semantics anyway. And not really very relevant in the here and now regardless.

j cade

RayDAnt said:

j cade said:

RayDAnt said:

j cade said:

RayDAnt said:

Masterstroke said:

Padone said:

@Leonides02 That's also my point exactly. A pbr skin shader must work in any light condition, otherwise it's a not a skin shader but just a "trick". Then the light setup has to be realistic itself of course. That is, forget about point lights for example that don't cast reflections and have no size.

Indeed it is hilarious that most acclaimed "realistic" method here is based on point lights.

might be true, but this means, that you can forget about "photorealism" with IRAY.

It's not possible. period!
Maybe ten IRAY versions later.

EDIT:
That said, Iray can produce nice renders for sure, but If you want photorealism, you're better off with VRAY, Octane or maybe Cycles.

See this article for 20 fine to extremely fine examples of what level of photorealism Iray itself was capable of more than ten versions ago (and a lot has changed for the better since then.) Keep in mind that when dealing with Iray in the context of Daz Studio, you are almost exclusively interacting with it from within the confines of Daz's own custom (oftentimes barebones) implementation of it. Specifically in the form of the Daz-authored UberShader and compatible 2nd/3rd party pre-packaged content.

 

 

While I agree with the sentiment, none of these renders seem to be Iray Most seem to be using Vray or Mental Ray

Nvidia bought Mental Ray from its original developer Mental Images in 2007, ported its core codebase to Nvidia proprietary Cuda code so as to make use of GPU acceleration, and then started offering it as an independent product called Iray starting in 2010.

 

Iray was shipped with mental ray for a while

Yes, because Iray started out as an experimental Cuda-based fork of Mental Ray that was made available to existing users of Mental Ray during early development stages since they were uniquely well placed to beta test it.

 

j cade said:

perhaps they share some code

They shared exactly the same core code as of 2007 or so. As already stated by me, much has changed under the hood for Iray since then. But not in a way that would make it less capable of giving photorealistic results than its predecessor (which is the context in which Mental Ray was presently brought up.)

 

j cade said:

mental ray also had a dedicated sss shader rather than using volumetrics

This sentence makes no sense. Volumetrics is a generic underlying render engine mechanism. Shaders are programmable bits of code that tell a rendering engine which of its supported generic underlying render engine mechanisms (like volumetrics) it should use in rendering specific aspects of a given image. You can have a "dedicated" SSS shader that tells the rendering engine to use only volumetrics. Or volumetrics plus other things. Or other things and no volumetrics at all. These aren't opposing factors.

 

j cade said:

To call  Mental ray an older version of Iray is very incorrect.

Yes, Iray is a fork of Mental Ray going on 10+ years now.

Okay I don't know how to phrase this in a way that doesn't sound kind of rude, but is there anyone besides you who has claimed Iray is a fork of mental ray? I ask, because I googled and I cannot did any reference to it as such,  but plenty of prople including some official nvidia stuff that seams to clearly refer to them as wholly different engines.

Maybe I phrased dedicated SSS vs volumes wrong, perhaps brute force volume vs dedicated shader, but the point is they are 2 pretty fundementally different methods there was no random walk back in 2010 so mental ray was using some form of diffusion to approximate SSS. I notice you skipped over the main part of that scentence where Mental Ray is a biased raytracer that uses photon mapping for GI That is an incredibly ground level difference. If its a fork that started out with the same cose why did it take til almost now to get some form of strand based hair, something Mental Ray had since well before 2007

 

Iray started out as an experimental Cuda-based fork of Mental Ray that was made available to existing users of Mental Ray during early development stages since they were uniquely well placed to beta test it.

A beta from 2010 to 2017? mental ray continued to have new features developed through 2016 at the least. 

 

Why are you both arguing over this nonsense? Post some photoreal pictures or start a Mental Ray vs Iray thread. Sheesh.

Hey now I can pointlessly argue and post photos

Some vellus hair expiriments that I forgot to save before a crash *tragedy*

after looking at a lot of reference I went for lots more strands but smaller and much thinner, still imperfect but it doesn't create noticable thick lines Trying to find the balance of "actually has noticable effect" and distracting is tough

 

Padone

@isidorekeeghan I don't feel your "proper" way is really "proper". These are just a couple of notes that you may want to consider. Not intended as criticism but rather as technical information that may be useful.

1) The reflectance tint is intended to be used with the mono sss where there is no other way to "adjust" the sss tint. With the chromatic sss there is no need for the reflectance tint and translucency should be set to scatter only.

2) Setting translucency greater than one may cause a break in the pbr chain, it is much better to adjust the texture to remain into pbr boundaries. This for example may cause "glowing" effects depending on the texture, the sss settings, and the environment light.

3) Setting a semi-white transmitted color means there is almost no absorption in the volume so you just have scattering effects. This sure makes sss more visible but the side effect is that the figure may appear "transparent" depending on the light conditions. I'd advice you to do some tests with scene lights only without a hdr map to see how the skin reacts to strong backlights.

4) The chromatic mode is buggy stay away from zero and one values in any color channel to avoid glitches. This is confirmed and reported to the daz support. Then 0.01 and 0.99 values are fine.

5) Turning off burn highlights and crash blacks has the effect of flat mapping the whole linear space to the output colorspace. This resembles human perception better. But it also flats overexposure and rim lights that may be required or not depending on the artist needs. To mimic real cameras it is not good to turn off those settings.

 

@jcade Your portraits are amazing. Sorry for the misunderstanding about point lights, as I'm used to cross platforms it comes natural to me referring to point vs area lights.

emoryahlberg

Padone said:

@isidorekeeghan I don't feel your "proper" way is really "proper".

What is with you people? His settings are gorgeous, they work, and he shared them with us for free. If you have better chromatic settings, I'm sure he'd love to see them. There's a lot of weird "this isn't proper PBR" and "this render engine is better" baloney in this thread. Isn't the point to make the most photoreal images as possible with iray?

 

 j cade that is a beautiful and, I daresay, photoreal render! Iray or Blender?

isidorekeeghan

j cade said:

isidorekeeghan said:

Hi everyone, i wrote a guide on how to properly setup subsurface scattering in daz/iray, i tried to cover everything, i posted it here https://www.deviantart.com/dfggcxbbb You can also get it from the attached file Hope it helps you understand things better

 

 

giving it color will put blue lines where two surfacess join when rendering with spectral rendering ON,

 Have you figured a solution to the blue line bug? My skin is clear, my crops are watered, you can have my nonexistent firstborn etc.

 

... quickly tested it on a scene where I kn ew the blue line was. and there was no blue line with colorless transmitted color. this is pretty fornicating exciting

Glad to hear that

emoryahlberg said:

isidorekeeghan said:

emoryahlberg said:

isidorekeeghan said:

Hi everyone, i wrote a guide on how to properly setup subsurface scattering in daz/iray, i tried to cover everything, i posted it here https://www.deviantart.com/dfggcxbbb You can also get it from the attached file Hope it helps you understand things better

This is great work, isidorekeeghan!

Here's an example employing your technique. The first one is my own chromatic shader which I worked forever on, but ultimately grew frustrated because my character's skin color kept changing. I had NO IDEA you could change the base color values above 1.00, and that alters everything.

The second one is with your technique, and I think the SSS is beautiful. The only thing I noticed is now the inside of my character's mouth is glowing. Also, my SSS glow is yellowish when it should be red.

Any suggestion?

Old SSS

 

 

New SSS

 

 

Thanks, just change the sss color hue to more redish color like 28 or something ,sss color is different for every skin ,some people have red some orange some pink, and what do you mean by glow i dont understand, maybe send me a close up

 

I actually ended up changing the sss color hue AND increasing the SSS direction, and that seemed to make it perfect!

Thanks to you, I believe I may have rendered my most photoreal face ever:

 

The only snafu is the glowing mouth. Here's what I mean:

I think your sss values are to high, thats why the mouth is glowing

Padone said:

@isidorekeeghan I don't feel your "proper" way is really "proper". These are just a couple of notes that you may want to consider. Not intended as criticism but rather as technical information that may be can be useful.

1) The reflectance tint is intended to be used with the mono sss where there is no other way to "adjust" the sss tint. With the chromatic sss there is no need for the reflectance tint and translucency should be set to scatter only.

2) Setting translucency greater than one may cause a break of the pbr chain, it is much better to adjust the texture to remain into pbr boundaries. This for example may cause "glowing" effects depending on the texture, the sss settings, and the environment light.

3) Setting a semi-white transmitted color means there is almost no absorption in the volume so you just have scattering effects. This sure makes sss more visible but the side effect is that the figure may appear "transparent" depending on the light conditions. I'd advice you to do some tests with scene lights only without a hdr map to see how the skin reacts to strong backlights.

4) The chromatic mode is buggy stay away from zero and one values in any color channel to avoid glitches. This is confirmed and reported to the daz support. Then 0.01 and 0.99 values are fine.

Thanks for the info, but i actully tested everything i said in the guid, i didnt want to clotter it with example of technical dessisions, the hdri map i used is this https://hdrihaven.com/hdri/?h=flower_road It has one of the strongest and btghtest suns, which makes it perfect for seting up subsurfacescattering, i reccommand getting it and testing it under that map, for reflectant tint i usually dont use it but its an option that comes with a scatter and transmitted which in my opinion is nececcery, scatter only doesnt let light pass through, which is not natural and if light comes from the sides the inside of the mouth wont get light , seting values over one is just an easy option i thought people should know its not the best option though,setting transmitted measurement distance to white is the olny way to get rid of blue lines, and for the transparent figure it means you didnt read the guid properly and put 1 or 255 in transmitted color, which i underlined and wrote in big font not to do, and whats buggy about chromatic mode? I didnt encounter any issus so far

isidorekeeghan

lilweep said:

isidorekeeghan said:

In the guide i also cover how to fix blue lines around seems so go check it out, final render example in attached file

thanks for guide; reading it now.

the first step might be a barrier to entry for people who dont know where to go (i.e., render settings) to adjust crush blacks and burn highlights.  Also "add zero in front of" should probably be "add zero after decimal".

i only mention this because i am very stupid and unironically got stuck for a moment on the "before we begin" stage.

I understant, i will update it with better instrctions, thanks

Masterstroke

One thing about Photo realism, I'm thinking about latley is: If we use HDRI maps for lighning environments, shouldn't we also use HDRI maps for props and rooms, for they bounce off lights as well and sometimes do have light sources themselfes.

Padone

@isidorekeeghan here

https://www.daz3d.com/forums/discussion/comment/5664261/#Comment_5664261

NylonGirl

So @sunnyjei posted this in Black is Beautiful and I think it also fits in here. At least I think I would have believed that was a real person if I hadn't been told it's Maddy HD.

isidorekeeghan

Padone said:

@isidorekeeghan here

https://www.daz3d.com/forums/discussion/comment/5664261/#Comment_5664261

Oh i see, but my sss setting doesnt violate any of that and in the guide you see that all of my color values are below 255 and they dont go near zero

isidorekeeghan

I updated the guid with clearer instructions and more examples, also you can use my setting on creatures and animals as well, also covered the glowing mouth problem and added an example with tattoos, please follow the instructions in the guide carefully for best results,thank you updated version attached

isidorekeeghan

Okey i said ,scatter only doesnt let light pass through, which is not natural and if light comes from the sides the inside of the mouth wont get light,ignore all that i misunderstood that with something else, scatter and transmit give us the option to change the tint that sss color transmits back or reflects back which is the opposite color of sss color, if you use my technic and set the sss for spectral rendering on then turn the spectral rendering off after were done you can see the skin looks green, that green is what sss color reflects back which is natural but we can change it with sss reflectance tint, therefor makes the scatter and transmitt neccecery , i sometimes confuse myself :) example attached. In the example you see the back of the head has greenish tint and the face has redish tint thats because i changed the sss reflectance tint of the face to a very saturated pink

emoryahlberg

Figured it out. Somehow my mouth was set to "thin walled."

Still working on the tongue, etc - but at least it's not glowing anymore!

 

isidorekeeghan

emoryahlberg said:

Figured it out. Somehow my mouth was set to "thin walled."

Still working on the tongue, etc - but at least it's not glowing anymore!

 

Remember to setup the eye sockets aswell, you can setup the mouth and the eye sockets the same way you setup the face, and thanks for the kind words earlier

Gordig

NylonGirl said:

So @sunnyjei posted this in Black is Beautiful and I think it also fits in here. At least I think I would have believed that was a real person if I hadn't been told it's Maddy HD.

It's a great render, but as so often happens, the hair really gives up the game. Also, the water is really low-res, and her left arm is clipping through the float.

Padone

@isidorekeeghan Black and white colors are special selectors that disable volume transmission (absorption) as well as scattering in the chromatic mode, that's why you get the "glowing" underbelly. Also with your settings you get an unnatural yellow translucency with strong backlights that I advised you to test. That's expected because of the yellow sss tint you choose.

Please note that the reflectance tint will have no effect on translucency from backlights since it is just a color multiplied with diffusion so it's most visible with low translucency. Indeed with 100% translucency the reflectance tint has no effect at all. Again reflectance tint is supposed to be used with the mono mode where we have no better alternatives.

Again this is just technical information that I hope may help you in your quest for a nice skin shader, it's not intended as criticism. Though I'd not call it the "proper" way to do things that is misleading, but just "my" way.

 

edit. Of course feel free to include any information I provided in your guide if you feel it may be useful to others. You don't need to mention me this is just stuff.

isidorekeeghan

Padone said:

@isidorekeeghan Black and white colors are special selectors that disable volume transmission (absorption) as well as scattering in the chromatic mode, that's why you get the "glowing" underbelly. Also with your settings you get an unnatural yellow translucency with strong backlights that I advised you to test. That's expected because of the yellow sss tint you choose.

Please note that the reflectance tint will have no effect on translucency from backlights since it is just a color multiplied with diffusion so it's most visible with low translucency. Indeed with 100% translucency the reflectance tint has no effect at all. Again reflectance tint is supposed to be used with the mono mode where we have no better alternatives.

Again this is just technical information that I hope may help you in your quest for a nice skin shader, it's not intended as criticism. Though I'd not call it the "proper" way to do things that is misleading, but just "my" way.

 

edit. Of course feel free to include any information I provided in your guide if you feel it may be useful to others. You don't need to mention me this is just stuff.

Thanks for the info, i appreciate it, i understand that my way is different and against some technical rules but it works and fixes alot of issues , and it also works in both spectral rendering on and off, for the color as i said in the guide its different for every skin and you can try any color to see what looks best, the underbelly glow test happens when we put 255 full value in the trasmitted color not because we put colorless value, as i said sss reflectance color as the name suggests only effcts what reflects back from sss color it has no effect on translucency or sss primary color, and for the proper part it is proper because we get the effect that ressembles real life human skin behavior which we didnt get from non of the characters that came with their default sss setting ,no offence to the people working on them

lilweep

So... any news on a script that puts Base Colour map into Translucency channel?

Both shaders (added to this thread) by Jcade and isidorekeeghan are using that approach.  I quite like the look of these shaders vs default shaders for most characters, but it can be tedious to move maps.

markusmatern

lilweep said:

So... any news on a script that puts Base Colour map into Translucency channel?

Both shaders (added to this thread) by Jcade and isidorekeeghan are using that approach.  I quite like the look of these shaders vs default shaders for most characters, but it can be tedious to move maps.

Take a look at Map Manager

It does all sorts of map management and has some specialized ones for skin management

From one figure to another:

One for the purpose you want: Copy from one slot to another on the same figure

t0mg_z

Thanks for the guide you put together  @isidorekeeghan , you helped me a lot on understanding the "why" for some settings. 

This is my attempt with a 3 point light setup, rendered with spectral = on. Not straight out from Daz Studio, as I rendered into canvas and did the tone mapping in PS. 

isidorekeeghan

.

t0mg said:

Thanks for the guide you put together  @isidorekeeghan , you helped me a lot on understanding the "why" for some settings. 

This is my attempt with a 3 point light setup, rendered with spectral = on. Not straight out from Daz Studio, as I rendered into canvas and did the tone mapping in PS. 

Im glad it was helpful, and nice render

emoryahlberg

Here's a test on darker skin with a G3 female. I think your settings are brilliant isidorekeeghan, AND you solved the infamous blue line problem!

First one is mono sss, second is chromatic w/ your settings. 

lilweep

^ looks a tad green.

 

What are good shader settings for vellus hair?

isidorekeeghan

emoryahlberg said:

Here's a test on darker skin with a G3 female. I think your settings are brilliant isidorekeeghan, AND you solved the infamous blue line problem!

First one is mono sss, second is chromatic w/ your settings. 

Thanks for the example, but the skin color is a little bit green , it could be the characters texture maps, i attached an example of my setting apllied to latonya 8

isidorekeeghan

Also here an example of my sss setting light absorbtion vs no subsurface scattering at all, as you can see it absorbs a good amount of light even though the transmitted color is set to 254. The figure is aureska hol head ridge