Still looking for the right SKIN

[Mattoo]

I try not to think about it too much, I've wasted countless hours coming up with all kinds of schemes for getting skin to behave in various lighting conditions.

You're best off designing your shading based on the scene in which it'll be used - you can guarantee it won't look right in the next scene setup so don't expect it to. For this you don't need much, a lot of the time you don't even need anything more than simple incidence gradients to get it looking good, but as I said, it'll fall appart in the next lighting setup.

I would say this was true if you were trying to get very realistic skin but of course if your standards aren't quite as high or you don't have that kind of time I'm sure a happy medium could be found that would work in most situations with little fuss. That's what most people do... I'm just a little obsessive.

[Gollum]

I still haven't found a perfect way to get good SSS on my skin surfaces, not without exponentially blowing up rendering times. Some of the SSS shaders readily available for MAX and Maya start to get me drooling I must say! It's about time LW gets a similarly good solution.

Thrijs trick does wonders for wax-like surfaces, but I can't really make good, believable skin with it, just an approximation that is similar to, though not as good as, the look you get when rendering with HDRI. Chanlum doesn't do the trick for me either. I always postpone trying Ska, which seems the best, but slowest, solution.

TB_Fakeskin is probably one of the best tips I can give, its pretty decent, although it doesn't to any type of "proper" SSS. But in combination with gradients and a good lighting setup its neat...

[Gollum]

I must be wasting way too much time on this subject. Been reading through the various skin related threads and it's driving me nuts to be honest. :scream: I already had a decent enough surface for my last character, textures and all, but I can't let go.

Anyway, I stripped away all of the textures to concentrate on the way that light interacts with the surface. I used a simple procedural bump (and some minor weigthpainting) to get a better feedback on some of the effects of SSS I was after (the "smoothing" of the bumps and "colourbleeding" as seen in the BSSRDF papers). While experimenting with different shaders the past days, I came up with a hack involving OGO_Hikari:

http://www.gkane.de/temp/fakeSSS_01.jpg

It's the the same scene/surface (rendertime is that of the 800x720 original), one rendered with OGO_Hikari applied, one without. Significant difference and not too much of a boost in rendering time. Of course its not real SSS, but definitely an improvement.

Hikari, like Ska, is capable of pulling off "real" SSS, but it takes quite long to render and is a bit on the complicated side to set up IMO: seperate inside and outside surface; with SDS the inside needs an offset; need to add another layer of geometry to regulate the strength of the effect; etc. If this could be set up with textures instead, it'd be way more practical and just as powerfull IMO! Thanks to the folks who did the translation of the Hikari docs BTW, its still vague and cryptic, but that's not your fault. ;)

I wanted something that's easy to apply and fast - and fast this is, as none of Hikari's "real" reatures (like SSS, caustics, radiosity) are activated. I just use the diffuse and translucency controls, as well as some specular coloring. I wish Newtek would purchase and enhance this code, its really something that deserves further development! :deal:

Unfortunatelly this technique still has several limitations. For one, it doesn't work well with shadows (yet). Raytraced shadows act like crazy and shadowmaps look funky too. I'm working on it, but for now its a job for post. Also, since it isn't real SSS, it won't to any fancy red ear or shinethrough effects, those still have to be faked seperately.

If anybody else is currently working on getting nice realistic human skin, I'd love to hear about your latest methods/see your results! :)

[leigh]

Remember that you can do a lot of post-work to improve the effect. Of course, getting a good looking render is important to begin with, but there are lots of tricks to improve the effect in post.

Such as copying your layers and saturating blue and red versions (depending on the effect you want), blurring them and blending them with the original renders.

The following image shows the original render (not a LightWave render though) with a slight red adjustment, followed by the contrasted, blurry blue saturated one, which is then multiplied over the original render, and finally colour balanced (with some cyan) and adjusted up slightly with curves. See what a big difference the post adjustments make?

This particular render is using a Phong shader, however I am going to switch to a Blinn one because the Phong shading makes it look slightly metallic. There is a Blinn shader available for LightWave somewhere (an Oren-Nayar Blinn), but I can't recall who did it. Also, rendering an ambient occlusion pass (use the occlusion shader that ships with LightWave) will help to create some definition that will take away some of the slightly waxy look that it has.

http://leigh.cgcommunity.com/images/brute_strip.jpg

[twidup]

hey leigh,

I am curious now, what renderer were you using?

-todd

[leigh]

This was out of XSI :) So... mental ray.

But I have seen similar results coming from LightWave, so it's absolutely possible in that too.

Apart from the aforementioned tips for post adjustment, also be sure to keep in mind that your lighting is critical. Subsurface scattering isn't going to magically make your skin look real - SSS is a really subtle element of skin, and it's absolutely possible to create realistic skin without it (or using a cheat). It's the lighting setup that is going to weigh far more heavily in the realism equation. You can have the greatest, most accurate shader in the world but if your lighting sucks, it's going to look crap.

People just don't spend enough time on their lighting. Learning some decent lighting techniques is an essential step to creating good looking work.

And yes, I know I still have a lot to learn on the subject myself!

[Gollum]

The subtleties of SSS are just one of the aspects of skin I'm trying to get a grasp of. I'm trying to improve my shading skill in general, which is still a bit lacking, but its getting better. The thread starter asked about SSS in particular though, so I thought I'd post my hack in case someone might find it interesting.

You're absolutely right about lighting, its as vital for the shading as the surfacing. I thought I should mention that the lighting for the sample I posted was incredibly simple on purpose and nothing I'd light a final render with.

Phong is certainly not ideal for skin, but LW users don't have much choice, do they? :) I've tried the Oren-Nayar shader for LW, but have had problems with the skin ending up looking way too dry, as in "desert that hasn't seen rain in 20 years" dry. Probably just didn't spend enough time with it, I'll try it again sometime. I have a feeling my quest for good skin is gonna take a couple more years... :shrug:

Thanks for the tips on post, your images give a good overview, thanks! I have to say the composite still looks a bit waxy. Still neat though!

[leigh]

With regards to the Oren Nayar shader - you're right in that it makes things lose specular definition. But personally I prefer avoiding specularity altogether with skin (the reason my tests here look waxy is largely due to the specular component of the shader that I haven't disabled yet in addition to to the lack of any textural variation), and using tinted reflectivity instead, at low levels. When using LightWave, you may get better results by rendering out the reflection shading channel and applying it in post.

I am hoping to tweak my shader to perfection tonight and then dump some images into it. I'll try and put together a collection of tips when I am finished (just really crazy busy at the moment!).

[gerardo]

You have a really nice result there :)
Have you considered to try exporting the depth channel of that character and apply it as a mask for the blend in your composition? I think this way is possible to have much more control on the blend manner of colorations along the skin surface



Gerardo

[ThirdEye]

http://leigh.cgcommunity.com/images/brute_strip.jpg

Great results Leigh, really. The model looks really good too, congrats. :)

[leigh]

You have a really nice result there :)
Have you considered to try exporting the depth channel of that character and apply it as a mask for the blend in your composition? I think this way is possible to have much more control on the blend manner of colorations along the skin surface


I am not familiar with that technique. I can't quite figure out why and how Z depth would affect the diffusion of skin? Could you show an example? :) I am quite intrigued!

Hey Thirdeye! Glad you like it :) That means a lot!! Here is a small update:

http://leigh.cgcommunity.com/images/brute_003.jpg
(don't want to post any more non-LightWave images directly into this thread heh)

As for LightWave itself, I never did have much luck with the depth gradient thing (it always looked weird) and I could never get any interesting results with Chanlum either. I think my LightWave skills are cursed!! :P

You're best off designing your shading based on the scene in which it'll be used - you can guarantee it won't look right in the next scene setup so don't expect it to. For this you don't need much, a lot of the time you don't even need anything more than simple incidence gradients to get it looking good, but as I said, it'll fall appart in the next lighting setup.

Yeah this is so true. Your skin can look totally awesome in one scene and absolutely awful in another. The cool thing about this is that you can therefore have free reign to go wild with your lighting setup. Remember that lights are artistic tools. They do far more than simply illuminate a scene - they give definition to the models by scultping them with light. Use this to your advantage - lights can be used to give colour, form, and life to a scene.

[gerardo]

I am not familiar with that technique. I can't quite figure out why and how Z depth would affect the diffusion of skin? Could you show an example? :) I am quite intrigued!

Sure, in this thread I made a test with TB'sFakeSkin and a depth map in post:

http://www.cgtalk.com/showthread.php?t=184476&page=4&p=1727871

In the same thread, I also made a similar test with cartoon skin achieved starting from LW gradients:

http://www.cgtalk.com/showthread.php?t=184476&page=6&p=1894540

(although, this skin is not realistic, the effect is applicable)

I try to explain in that thread how I did it; but basically, the idea is to do a depth map (rendered without antialiasing and at doubled resolution) and use it as alpha channel to define the areas we want to show of our image version without processing; under the revealed areas we can show the zones that we want to process (warm or cold tones, blur, glow or different blending modes). This can be made in several layers to achieve a more complex effect. The advantage of making it with a depth map, is that these variations and color effects are made along our character's surface and are consistent if we move the character or lights, what causes an effect of coloration change according to the depth level of light that is scattered in surface. If we want color variations with more or less depth, we increase or decrease the contrast of our depth map. The Z-Buffer is used by several shaders to achieve this effect in the same 3d software; do it in post however provides us more versatility, I think.
About Chanlum, at least for me, can be a good starting point for realistic skin; this shader is really nice but the plug is nothing if it's not adapted well with lighting setup.
Btw, you've made a great job with the last image :thumbsup:



Gerardo

EDIT: I've just remembered we can also make some color variation according to Z-Buffer, directly in LW, with LocalAmbient Pixel Filter :)

[INFINITE]

:) Hey guys some interesting stuff. Shame LW cant produce even basic wax stuff like XSI and it would be cool too get great SSS/skin effects without post processing :)

One day, who knows. I have a feeling Worley has got some tricks up thier sleeve. Must. . . . . be. . . .patient. . . .

[leigh]

It is certainly possible to get good skin renders out of LightWave. The Ripper has done so many times, although I have no idea how and he's certainly not telling.

[leigh]

Sure, in this thread I made a test with TB'sFakeSkin and a depth map in post:

http://www.cgtalk.com/showthread.php?t=184476&page=4&p=1727871

In the same thread, I also made a similar test with cartoon skin achieved starting from LW gradients:

http://www.cgtalk.com/showthread.php?t=184476&page=6&p=1894540

(although, this skin is not realistic, the effect is applicable)

I try to explain in that thread how I did it; but basically, the idea is to do a depth map (rendered without antialiasing and at doubled resolution) and use it as alpha channel to define the areas we want to show of our image version without processing; under the revealed areas we can show the zones that we want to process (warm or cold tones, blur, glow or different blending modes). This can be made in several layers to achieve a more complex effect. The advantage of making it with a depth map, is that these variations and color effects are made along our character's surface and are consistent if we move the character or lights, what causes an effect of coloration change according to the depth level of light that is scattered in surface. If we want color variations with more or less depth, we increase or decrease the contrast of our depth map. The Z-Buffer is used by several shaders to achieve this effect in the same 3d software; do it in post however provides us more versatility, I think.
About Chanlum, at least for me, can be a good starting point for realistic skin; this shader is really nice but the plug is nothing if it's not adapted well with lighting setup.
Btw, you've made a great job with the last image :thumbsup:



Gerardo

EDIT: I've just remembered we can also make some color variation according to Z-Buffer, directly in LW, with LocalAmbient Pixel Filter :)

Interesting technique! And you've got some very nice results there too :) Thanks for sharing!! I will do some experiments with Z-Depth passes this weekend!

[INFINITE]

Hey Leigh,

Yeah I agree The Ripper has done some amazing work but I read some where in one of his old posts that he does post process stuff in photoshop, so still not an out of the bag render from LW.

Have you had any joy with Ska?

[leigh]

Ska took too long to render for my tastes heh. I have gotten some nice looking stuff out of G2 though. I did these renders about a year ago, they're quite outdated now but I was pretty happy with them at the time.

http://leigh.cgcommunity.com/images/taziyah_01.JPG

http://leigh.cgcommunity.com/images/henry_02.jpg

[INFINITE]

Good stuff Leigh, like the pics. I have used G2 as well. Found it a little buggy and hard too control really, hopefully a G2 update might appear at some point :)

[Gollum]

The Ripper has given a rough rundown as to what he's doing several times. First his skin relies on detailed texturemaps (and from the look of hsi renderings those ARE truly awesome), but also greatly on using Monte Carlo Radiosity with at least 2 bounces IIRC, something that's a bit of a killer for animation. He's also worked with Ska and G2 to get SSS, no idea how extensively though (some of his older work was definitely done without either one of them). At least with regards to Ska, he posted a quick guide on rendering out the SSS at a lower res, to save rendering time, and then composite the diffuse scattering effect in PS.

I've started experimenting with TB's shaders yet again (Fakeskin and 2nd surface), the additional gradient options make his shaders very powerfull.

[gerardo]

Leigh, I like a lot your Mental Ray example, but Wow! you have achieved fantastic results in LW too :applause:
For this image:
http://leigh.cgcommunity.com/images/brute_003.jpg
I would swear you used a depth map. How did you make it?

I N F I N I T E, I think we can obtain a basic wax effect in LW through gradients or with Chanlum shader without problem :)



Gerardo

[leigh]

Thanks for the compliment :)

For that particular render you mentioned, it's simply an update of the previous series of renders, except this time I used a very rough colour and bump map on it. So all it's using is the Blinn/diffusion combination. No depth at all.

[gerardo]

When you say blinn/diffusion combination, you refer to the options of the XSI shader, right?
I only know one shader for LW that makes this type of specular effect, I thought Blinn was a distribution method designed exclusively for specular attribute. Sorry, I haven't slept and don't understand well :blush: do you export the specular or diffuse buffer?



Gerardo

[leigh]

I have done a screengrab here so you can see my shader tree and the raw render in the viewport render region.
Blinn is just a different shading model to Phong. It is a virtually identical shading model to Phong except that yes, it has a small difference in the specular component of the model. It is more suitable for rough surfaces than Phong, from what I understand.

I did not create seperate specular or diffuse elements here at all - in my screengrab you can see in the render region exactly what the raw render without any colour adjustment in Photoshop.

As you can see from the node tree, the material consists of a blend between the diffusion and the Blinn shading models (I am still using Phong for the shadow shading though).

Hope this makes some sense.

http://leigh.cgcommunity.com/images/xsi_screeny.jpg

[INFINITE]

Maybe this is the wrong section of the forum's for an xsi screen grab etc? :wise:

[leigh]

You know, I really knew that someone was going to say that sooner or later. It's software, not a religion, so being offended by it is really a waste of energy.

He asked a question, I thought it best to show the shader flow. Excuse me for being helpful.

I'll refrain from trying to help in future then. Sorry.

[gerardo]

Maybe this is the wrong section of the forum's for an xsi screen grab etc? :wise:


I don't think so. The software has nothing to do here. This screengrab is really very useful for us (at least for me) since it can help us to understand the logical structure of the aspects in the light interaction with a surface that we should take into account to achieve a good result. For a variation of the technique to achieve this cartoon skin with Chanlum:

http://www.geocities.com/gerardstrada/Incsss.txt

That I explain here (without using Chanlum):

http://www.cgtalk.com/showthread.php?t=176195&p=1853072

I took it from a Messiah screengrab that Taron shared to explain his skin shading:

http://www.taron.de/Storage/tutorials/Neckling_shaderflow.jpg
http://www.taron.de/Storage/tutorials/Extended-section.jpg

From this interesting thread:
http://www.cgtalk.com/showthread.php?t=187770

What I made was to interpret those aspects and to adapt them to LW tools using the tricks and available shaders that we have by hand. At least, after that, was the first time that I could achieve a latex effect, so difficult of achieving with just Thrij's trick; since the phenomenon and factors to take into account are more complex as to only solve them with a gradient based on object distance. I discovered after that, that we can simulate Lambertian and OrenNayar's diffuse effects and Phong and Cook-Torrance's specular effects with spining lights rigs and spinning nulls in gradients.

So thank you Leigh! your screengrab has given me a lot more ideas to play :thumbsup:



Gerardo

[duke]

Looking at the plugin itself http://animus.brinkster.net/stuff/plg_diffusion/plg_diffusion.html, he has included the source code, and so it could probably be made into a LW plugin - or better yet, a node in TB_ShaderTree :D

[ThirdEye]

Blinn is just a different shading model to Phong. It is a virtually identical shading model to Phong except that yes, it has a small difference in the specular component of the model. It is more suitable for rough surfaces than Phong, from what I understand.

Blinn and Phong share the same illumination base, which is the Lambert shader, but offer different specular responses. Generally Blinn is capable of keeping a round shape even when viewed with extreeeeeeeme camera angles; for example let's consider a ball here, a phong specular becomes stretched along the edge, it follows the contour of the ball, a blinn one keeps its round shape. I usually use Oren Nayar for skin, paper and textiles, Blinn for metals, Anisotrophic for anisotrophic metals and Phong for anything else.

[inno8sky]

It's software, not a religion, so being offended by it is really a waste of energy.



You know even if it is a religion people should be far more open minded, obviously I don't understand why people get their panties in such a twist over this. Honestly it shouldn't matter which application is being used, especially when the screen grab was there not as an advertisement for another application but as a tool to better illuminate an approach or concept.

I for one really appreciate your willingness to share your experience and insight Leigh. Please don't let some goomba prone to knee jerk reactions prevent you from sharing in the future. There are thousands of visitors here that don't share that particular perspective.

By the way, in addition to your posts on this and other sites, I've thoroughly enjoyed your book LightWave 3D 8 Texturing and really like the approach you took in it to educating. I always thought following steps were less valuable than understanding why, it's a shame more books don't take this approach..

Cheers,

[INFINITE]

Please don't let some goomba prone to knee jerk reactions prevent you from sharing in the future.

No need to be rude pal :twisted: I was just stating a fact but I do apologise if I offended you Leigh:sad: , it just infuriates me when other applications are brought into the equation by people. I have seen other applications and know how good they can acheive skin, the topic was originally about how LW 8 can do the same thing. After all this is the Lightwave forum but I do agree sharing information from other programs is important, so I stand down. After all we are looking for the same thing. Never been called a Goomba before. Cheers :shrug:

[Gollum]

Very interesting observations gerardo, I really enjoy reading your posts, they're certainly among the most informative around. Taron's info on extension depth in Messiah is very interesting. You don't know how frustrating I currently find the fact that gradients and other shaidng options in LW are limited to the 0-90° range!

Hikari looked like a solution, as it offers diffuse angle settings beyond 90°, but setting higher values didn't make any difference during my tests unfortunately. TB's shaders offer a bit more shading power in that you can link your gradients to overall phong or diffuse values (not limited to a single incidence angle or lightsource), something which I've been gravely missing in plain LW. I've really enjoyed experimenting with these the past days.

Leigh, as far as I can see only one person in this thread seemed to havy a problem with you posting that XSI grab, please don't over-react because of that. I personally think its great that you're providing some background info on your current shading explorations, LW or not. Maybe we can't recreate your settings, but that doesn't mean we can't learn from them. :)

[ThirdEye]

I have done a screengrab here so you can see my shader tree and the raw render in the viewport render region

It'd be nice to see the settings of the dispersion shader by Daniel Rind if you don't mind. It's quite tricky to use i think, but very very good.

[Chewey]

Thanks for sharin the XSI screenshots Leigh. Always interesting to see how you do your texturing thang regardless of application.:)

[Breuer]

Hi there!

Vey interesting topic. I have done some tweaking i LW8 and come up with a few "decent" skin shaders. It is of course a very difficult thing to do, to make realistic skin, and as someone mentioned here, it has alot to do with lighting.

Here's an example of one I've made. It uses only native LW settings and shaders. If anyone's interested, I could post it here so people could have a look at it and maybe get some better results!



Breuerhttp://breuer-visuell.com/test/shadertest2.jpg

[INFINITE]

Still looking for the right SKIN. .

[duke]

Heh, I was playing around with TB_Shadertree yesterday too, trying to get that extension thing going. It doesn't want to! I tried using the Wrapped Diffuse node in various way which *should* do exactly what it says it does.

I didn't keep going because I wouldn't be able to come up with satisfactory result due to a few features in shadertree. Macro input (give the input a name, type (colour, percentage, value), more than 1 macro output thingy, and a seperate ambient channel that takes into account colour and intensity so it ignores LW's ambient (otherwise you have too much dependency and it can mess up the shader, although I'm sure it would be workable). If the macro stuff was in we could make macro shaders with easy controls for the user, as they'd just feed their skin textures into the macro, give it a few values, and off they go, without needing to hack away at the structure of the shader itself (although the option would still be there).

[gerardo]

Very interesting observations gerardo, I really enjoy reading your posts, they're certainly among the most informative around.

Hey! Gollum I appreciate it :)


Taron's info on extension depth in Messiah is very interesting. You don't know how frustrating I currently find the fact that gradients and other shaidng options in LW are limited to the 0-90° range!

Hikari looked like a solution, as it offers diffuse angle settings beyond 90°, but setting higher values didn't make any difference during my tests unfortunately. TB's shaders offer a bit more shading power in that you can link your gradients to overall phong or diffuse values (not limited to a single incidence angle or lightsource), something which I've been gravely missing in plain LW. I've really enjoyed experimenting with these the past days...

For this reason I use spinning lights, to extend the light scattering along the surface; together with gradients and spinning nulls (as object reference) we can simulate the degree and level of light penetration and color variation according to surface depth. For that reason I find the screengrab of Leigh very useful and I suppose some shaders developers too (hey Pipari! where are you?!) to reproduce the same effect in LW. Hope to have some time to make more tests and show some other examples :)




Gerardo

[INFINITE]

Without meaning too seem rude or piss anyone off. How is the XSI screen grab relevant to Lightwave 8's Texture settings. There is no real corelation from what I can see + the renderer is slightly different and IMHO I think Leigh slightly over reacted and all the fan boys jumped on board. I personaly dont do that, I myself am not a schmoozer.

So how is the screen grab relevant in a Lightwave forum. Im being honest and interested not wanting to step on anyone's toes. Does lightwave have a plugin to simulate the texture setup of XSI?

Maybe someone should post some Max settings?

[ThirdEye]

Does lightwave have a plugin to simulate the texture setup of XSI?

that should be your brain in theory... :shrug:

[INFINITE]

that should be your brain in theory... :shrug:

Of course that explains it all, lightwave and XSI are so similar ? :shrug:

[gerardo]

Without meaning too seem rude or piss anyone off. How is the XSI screen grab relevant to Lightwave 8's Texture settings. There is no real corelation from what I can see + the renderer is slightly different and IMHO I think Leigh slightly over reacted and all the fan boys jumped on board. I personaly dont do that, I myself am not a schmoozer.

So how is the screen grab relevant in a Lightwave forum. Im being honest and interested not wanting to step on anyone's toes. Does lightwave have a plugin to simulate the texture setup of XSI?

Maybe someone should post some Max settings?



:curious: Although her work and constant contribution is Remarkable, I'm not a fan. If you read my answer, you would realize that I've sustained why that is relevant:

"What I made was to interpret those aspects and to adapt them to LW tools using the tricks and available shaders that we have by hand. At least, after that, was the first time that I could achieve a latex effect, so difficult of achieving with just Thrij's trick; since the phenomenon and factors to take into account are more complex as to only solve them with a gradient based on object distance. I discovered after that, that we can simulate Lambertian and OrenNayar's diffuse effects and Phong and Cook-Torrance's specular effects with spining lights rigs and spinning nulls in gradients"

and here:

"For this reason I use spinning lights, to extend the light scattering along the surface; together with gradients and spinning nulls (as object reference) we can simulate the degree and level of light penetration and color variation according to surface depth. For that reason I find the screengrab of Leigh very useful and I suppose some shaders developers too (hey Pipari! where are you?!) to reproduce the same effect in LW"

In other words, is relevant for people who know techniques and shaders that can reproduce the same effect in LW. Is relevant for people who program shaders. Is relevant for people who want to understand how another software interprets the phenomenon of the light interaction with a skin surface; and how another software solves the elusive theme of realistic skin. An objective who all CG artists, even 2D CG artists, continue looking for.
Is relevant even for those that cannot understand all this, since is a healthy manner to provoking at Newtek, so that they develops tools like those, and allow people that don't understand anything of this, to achieve acceptable results.
You will continue looking for the right skin, as all 2D and 3D CG artist :)



Gerardo

[duke]

:curious:

What he said ^.

Like all art, observation is a huge part of archeiving results in our preferred medium. The whole issue of "what's an XSI screenshot doing here" was a silly notion in a first place, but to spell it out for you, just like looking at the end result, it's of interest to see how its done - no matter what program, medium, etc.

[ThirdEye]

Of course that explains it all, lightwave and XSI are so similar ? :shrug:

yes they are, all the 3D apps are based on the same concepts, up to you to interpret Leigh's work in XSI and understand what she did and maybe transfer it to Lw.

[INFINITE]

Thats a very reasonable response Gerardo. Makes much more sense.

I was just getting abit offended because people tend too jump on the band wagon of the forum leaders for some sort of Kudos and then start a witch hunt.

":curious: Although her work and constant contribution is Remarkable, I'm not a fan."

I agree also, Leigh does put in a tremendous amount of work and help for all, in the forums.

Your explanation is cool :)

Will keep working on the skin. . .

[gerardo]

If you found something interesting, don't doubt to share it :thumbsup:



Gerardo

[duke]

I took a 30 sec (retimed to 14secs) video involving a flashlight and my arm :| Theres the original plus one i've thrown a median filter on and filtered out everything but the lighter parts. Hopefully this is of some use.

(xvid codec)
http://www.dukecg.net/skinMov1.avi

http://www.dukecg.net/skinMov1_lightIsolate.avi

[sllink]

Hi there!

Vey interesting topic. I have done some tweaking i LW8 and come up with a few "decent" skin shaders. It is of course a very difficult thing to do, to make realistic skin, and as someone mentioned here, it has alot to do with lighting.

Here's an example of one I've made. It uses only native LW settings and shaders. If anyone's interested, I could post it here so people could have a look at it and maybe get some better results!


Breuer

I would be interested is seeing your settings Breuer. The work on your site is inspiring.

[Zarathustra]

... people tend too jump on the band wagon of the forum leaders for some sort of Kudos and then start a witch hunt.


It's some kind of character flaw epidemic online. People glom onto who or what's perceived to be important like moths to a flame and lash out at those who don't worship the flame, too. You feel the backlash if you point out a bug in LW, a plugin, someone's animation, book, dvd, etc. It's really annoying, actually.

Gerardo's explanation of why Leigh's XSI examples are relevant makes sense, but then if you follow that point it doesn't seem worth having this thread because you could just go and read through the Skin Thread that Leigh started on CGTalk awhile ago which is very good and has LOTS of pages of examples from various apps and users.

Infinite seems to want an all-purpose, LW specific skin setting and I don't think there is such a thing. Everything is tailored to the specific shot and has to be perpetually tweaked. That's not what anyone wants to hear, but that's the way it is.

It's just the same old deal of constantly observing life, experimenting and attempting to deconstruct and recreate the techniques of other artists whose works you feel are the best and where you want to be.

[inno8sky]

Without meaning too seem rude or piss anyone off. How is the XSI screen grab relevant to Lightwave 8's Texture settings. There is no real corelation from what I can see + the renderer is slightly different and IMHO I think Leigh slightly over reacted and all the fan boys jumped on board. I personaly dont do that, I myself am not a schmoozer.

So how is the screen grab relevant in a Lightwave forum. Im being honest and interested not wanting to step on anyone's toes. Does lightwave have a plugin to simulate the texture setup of XSI?

Maybe someone should post some Max settings?

You're the one that's consistently overreacting, both in the initial post where you suggested that Leigh somehow did something wrong by using a screen grab to better illuminate the concept behind her approach and now this gem.. Man give it a rest, you cannot mitigate your reaction by sloughing off the blame elsewhere. She did nothing wrong with in the context of the thread…

Here's a similar situation, although you'll likely miss the subtlety; Sergio Garcia takes the world press to task over the heavy press coverage that Tiger Woods receives day in day out. He's unhappy that they don't devote more time to players of his stature. The comment expressed to Sergio was, "once you've won as much and as often as Tiger you too will get the same attention". Once you’ve contributed to this community on par with Leigh, people will listen more intently to what you have to say, although, I suspect they’d still shoot you down for that dumb comment, it was just out of place.

The point is, most don't give a pinch of coon dung about your thoughts or feelings on this matter because it’s off base. If for instance Leigh would have added, “I use this application for this because LW blows!” Then maybe you’d have a better argument, but that didn’t happen did it?

You were over the top in making that comment, NO ONE CARES about the screen grab, because you'd have to be a total idiot not to recognize why it was there and how it was being used.

Leigh is a huge contributor here, and I’d hate to see some lame comment cause her to hesitate about sharing here. Is this schmoozing or just common sense?

Don’t answer this, the question is rhetorical.

[INFINITE]

"Don’t answer this, the question is rhetorical" Well I will because:

You are the only one in the thread who has insulted me, I can only guess you are a child or you are just a rude person. I didn't insult Leigh or anyone else I just stated a simple fact, she overreacted and you joined in. After all I have already bloody apologised.

Read what Zarathustra said, he stated it how it is.

Have a nice day and in future maybe show some respect to others :)

Now why not drop it and continue with the topic in hand XSI, Lightwave or what ever. . .

[inno8sky]

You are the only one in the thread who has insulted me.

How did you become a victim here? My first submission was directed specifically at Leigh, to show support for her, the second was in response to your sarcastic reply. I guess it makes perfect sense that anyone that disagrees with you must be doing so for some ulterior reason.

Schmooze: To converse casually, especially in order to gain an advantage or make a social connection.

This isn’t insulting?

Goomba, if this is what you're referring to is an Italian word meaning friend, an acquaintance. I carefully didn’t use a direct insult, by calling you a knob, a prick, or a**h***, I didn’t think what you did warranted that.

You state that Leigh overreacted; I say you overreacted; you’re the egg before the chicken. If you had not said what you said, she wouldn’t have been offended, I wouldn’t have chimed in.

Yes I’m a child, a 44 year old child with 3 twenty something children. I’ve run a successful business for over 15 years in a totally different sector so there’s no need for me to schmooze anyone. In fact, I’m usually the one being schmoozed.

Last comment from me, unless of course you say something that really pisses me off :)

[INFINITE]

Goomba : The Goomba is also the weakest enemy in Nintendo's Super Mario Bros. video game series.

:) Like I said that comment really hurts :D. Joke.

Anyway back on topic, I posted this model over at the Newtek forum a while back, I would be interested to see if other LW artists can play with the texture settings on this model and keep sharing their ideas through this file? Just an idea. Best viewed with FPRIME.

Gerardo: would love to see what you could do with this simple file? Maybe strip the scene and start a fresh?

[DotPainter]

In regards to the original post, it seems that there is not yet a truly versatile skin shader that comes in any 3d package and suits all tastes. Most applications contain shaders and options for sub surface scattering, which is based on algorithms developed for siggraph a few years ago. However, this approach is more like using a sledge hammer to hit a nail when tring to build realistic skin. A true skin shader should use SSS, layers, surface thickness and some sort of volumetric translucency to really be effective and somewhat easy to use IMO. The SSS effect of skin is based on light going throug the upper dermal surface of the skin, hitting layers of miniature blood vessels (that vary in color from red to blue to green), through layers of fat, gristle and bone and then back out again. This effect is normally most pronounced on areas of the body where the skin is thinnest, ie the ear and nose and then only under certain lighting conditions. Therefore a good skin shader also needs other light transport models to accurately sample incoming rays to accurately and properly calculate the effect on specular, ambient and luminosity both in the areas where light can come through the skin as well as areas where skin has more fat, bone and muscle.

Because of the complexity of true lighting and skin, most renders I have seen still look somewhat fake (no matter what package or shader), since the SSS effect is overly pronounced and often makes the skin look like a big lump of red wax (like those photos of infants in the womb, without much bone or cartilage). XSI doesn't really have a good skin shader and what Leigh posted points that out, in the sense that the diffusion shader she is using is a 3d party shader that seems to have better light transport properties (ambient/diffuse impact) than the default xsi light transport shaders. However, the thing that xsi does allow is more control over various surface channels like shadow and photon, which is a good way to simulate the way light bouncing effects the skin surface both at the extreme angles that produce the SSS effect and areas of shadow/ambient light. Either way, creating skin in XSI is not a simple affair at all.

3ds Max has a sss shader, and I am not as familiar with it as XSI, since I don't own it, but once again, you have to put a lot of effort into combining colors, shaders models(blinn etc), luminance channels and other things to get the proper impact.

There are a few issues that complicate skin shader creation in lightwave, namely lack of a native SSS shader, color maps only available in color channel and lack of different light transport shaders (blinn, oren nayer, phong), along with some others (gradient options). This greatly complicates the process of making a shader and combining the channels properly, since even without SSS you can pull off a nice skin effect with the creative use of color maps in the various channels (which is used most often in most other packages). However, since most skin shading is subtle anyway, you can create a fairly realistic skin shader in lw, but the key, IMO, is subtlety. In otherwords, only create the SSS effect when it is needed and focus more on basic things like lighting, color, illumination, specularity and bump. Proper use of those things will go a long way in creating an effective skin shader in most cases.

Here is a Cinema 4D skin setup for comparison:
http://www.cgtalk.com/showthread.php?t=142645

[Pancho]

What I don't get: There are so many threads in all the forums around trying to find the right settings for skin or abusing shaders which never were meant for skin shading to do exactly that. This story now goes on for several years. Newtek, Worley, Dynamic Realities, independent programers, everybody knows nowadays about this demand. Why the hell is nobody giving us what everybody is asking for? It can't be that hard to create a shader like this. Honestly, it becomes kind of wired. I bet we'd be able to fake it if gradients would cover 360° and not only 180°, but that is another issue.

The point is: Who is going to solve this problem? I'm sick and tired of going out to hunt a collection of shaders which give me - after several days of trial and error - something that looks a bit like skin, but isn't able to do this or that.

I want some feedback from someone who is or feels responsible to solve it. Reading complaints, nice ideas and tricks at this state of computer graphics development gets pretty boring as you know this thread won't solve it (Otherwise it would be called: My favourite settings for SKIN-NER).

It's all like collecting pieces of plastic and rubber to create a doll. But this doesn't get you closer in any way to a real human.

Cheers
Pancho

[Gollum]

Why the hell is nobody giving us what everybody is asking for?
Good question, either because there is no simple, single solution that fits all needs, or because it isn't currently possible in LW (the popular SDK limitations argument). There are plenty of tools, G2, Ska, Hikari, Chanlum, etc... none are perfect but they can all help. It'd be nice to have something like the misss shader for LW, but even that won't do any good on its own as you still need to know what you're doing. I've been reading up on skin for a while, yet I still feel I haven't really grasped the full complexity of the (t)issue... ;)

It can't be that hard to create a shader like this.
Apparently it isn't easy tho, or we'd be flooded with great skin shaders. You should read Pipari's skin shader thread. Unfortunatelly he seems to have disappeared (quite a shame, his plugins rock!), but when you read through his thread you can get lots of information on what goes into creating such a shader and why it currently isn't easy to write one for LW...

Honestly, it becomes kind of wired. I bet we'd be able to fake it if gradients would cover 360° and not only 180°, but that is another issue.
Agreed, that would help a lot, we'd also need new gradient input types though. For now I'm using TBs shaders to give me many gradient options plain LW doesn't offer. I'm hoping LW point releases will adress this issue, hopefully sooner than later...

The point is: Who is going to solve this problem?
We all need to find our own solutions, based on our individual requirements. One user might be looking for the perfect ultra realistic skin for a still, where its okay if a render takes 10 hours or longer. Another wants something that renders fast and can be used for animation. By exchanging our knowledge here, we can all learn and profit from each other's experience. That's what this place is for IMO! :)

[Gollum]

BTW, here's a WIP of something I've been working on the past few days.

http://www.gkane.de/temp/skin_02.jpg

I'm using texturemaps and gradients to tame TB_fakeskin and am finally getting to a point where I'm satisfied (at least temporarily). Basic post work in PS (level adjustment and an occlusion pass, nothing fancy). Lighting is spotlights with shadowmaps, so it renders pretty fast. I'm sure similar results could be achieved without the use of a shader, but it does offer some unique gradients that I find very usefull.

[monovich]

I just downloaded TB_fakeskin and it seems to be an amazing plugin. I've never tried skin before, and don't know what all the considerations are, but what do people consider the shortcomings of this plugin to be when trying to achieve a good skin, in a nutshell? (besides being a shader).
I've only played a bit, but it seems to be failry easy to get some decent skin out of it. I could post my only render, but it's a lot simpler than what's up here so far.



-s

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