misss tests

[Demark]

I’ve returned to this skin things now and I see no word about pass idea I’ve mentioned, that’s a pity.

Recently a friend of mine asked me to make a video for him about all these ctrl_misss_pass things and I’d recorder both techs for him - first one with misss_fast_skin_maya phenomena and then another - discussed above - through misss_fast_shaders and then I’ve composed them in Shake. I thought that it could be helpful to understand the idea, so I’ve decided to post it here… Maybe it’d be useful for someone, maybe someone would make tests, find bugs, tell ideas and so on. Here it is:

http://www.sigillarium.com/articles/ctrl_misss_hand.avi
(TSCC, 161 Mb)

P.S. That’s not about skin right now (so, don’t blame me for overall look :)) just the way to make passes, so I use just my old model for testing purposes (that’s what I fear - when I plug special maps in each layer there could be bugs with network - so I hope someone would test it, 'cause, I fear, I can’t really find time right now to dive into this).

[MasterZap]

Ok, forget about it, I’ve found it !
My mesh seems to have some problems :banghead: …

Well a higher mesh resolution would help, but it looks like you have a little bit too broad specular and a little hair too much bump.

BUT this is a general problem in rendering, not just mental ray, not just this shader… if you use extreme bump, you will get fairly much light on polygons that are very nearly glancing the incoming light BUT as soon as the polygon starts to face away from the light, it is inherently “in shadow of itself” and hence receives NO light from that lightsource. So what you see is kinda a normal side effect of strong bumpmapping on polygon geometry. It’s just that the edge-enhanced specularity of the skin shader tend to accentuate this inherent problem.

/Z

[MasterZap]

floze, I’ve already read about your monolith, but haven’t tried it yet. As well as I remember, misss is one of the passes there, but whole misss. I’m talking about separating layers in misss_fast_skin in different files - diffuse, epidermal, subdermal, back and specular (which for now holds also reflectivity). If I understood you correctly

This is fairly doable by dissecting the phenomena into parts, and feeding each to a framebuffer. You can just write

• diffuse shader
• one copy of misss_fast_shader for epidermal
• one copy of misss_fast_shader for subdermal
• third copy of misss_fast_shader for back (but it’s more efficient to put it in the same fb as subdermal)
• one framebuffer for misss_skin_specular

That should be fairly simple to create.

/Z

[MasterZap]

Hey Zap, or anyone else.
I took a look to this post:
Had a go with these pics to understand the process what goes on under the hood a bit better. But somehow I had hard time to put the whole thing together properly. Now, I am not certain if I did it correctly after all, I just tried to see what looks good. I can see that the fleshy look for example is gone, or it is not so strong anymore.

I think you did pretty well… admittedly, I never made a green guy that looked really “fleshy”, since the redness seems to be an integral part of looking “fleshy”.

Can you Zap or anyone else reccomend good links or can you give some tips more precisely about post process of it. I find it very intuitive to bring whole skin rendering to post since there you have way better feedback and more room for various experimentations.
True. Well it’s basically weighted addition (or compositing with “screen”) between the layers, which should get you a very similar-ish result.

EDIT: Hey Zap, I thought I thank you personaly for this, your sss tutorial rocks totally.
One tries!

But thank you!

And guys in this thread: VERY NICE PICTURES. I wish I had time to comment on everything but… the day only has 48 hours…

/Z

[Splin]

I think you did pretty well… admittedly, I never made a green guy that looked really “fleshy”, since the redness seems to be an integral part of looking “fleshy”.

And guys in this thread: VERY NICE PICTURES. I wish I had time to comment on everything but… the day only has 48 hours…

/Z

OK now I understand it, in that picture I turned the red subtermal layer to green. But that is good tip indeed. Red is right for human skin(of course if the poor little still lives). But if I do sss for banana example, I understand my subtermal should also be accordingly at the color of “inner” banana.

Zap, in which world or planet do you live…48 hours long day would be nice indeed! Mine is only 24 and half of that is night

[gpepper]

Well a higher mesh resolution would help, but it looks like you have a little bit too broad specular and a little hair too much bump.

BUT this is a general problem in rendering, not just mental ray, not just this shader… if you use extreme bump, you will get fairly much light on polygons that are very nearly glancing the incoming light BUT as soon as the polygon starts to face away from the light, it is inherently “in shadow of itself” and hence receives NO light from that lightsource. So what you see is kinda a normal side effect of strong bumpmapping on polygon geometry. It’s just that the edge-enhanced specularity of the skin shader tend to accentuate this inherent problem.

/Z

Thanks Master !

Here is my last test with this cool shader !

[MasterZap]

OK now I understand it, in that picture I turned the red subtermal layer to green. But that is good tip indeed. Red is right for human skin(of course if the poor little still lives). But if I do sss for banana example, I understand my subtermal should also be accordingly at the color of “inner” banana.

Not only that, it’s physics; short wavelengths (the blues) extinct faster than reds in a medium. Or something like that. Like how sunsets are red? I dunno I lost my particle accelerator.

Zap, in which world or planet do you live…48 hours long day would be nice indeed! Mine is only 24 and half of that is night
Someone had in their signature “the day has 24 hours, but if that isn’t enough, we’ll take the night”… forgot who.

/Z

[MasterZap]

Thanks Master !

Call me Zap, Master is just a title (In reality it’s a long story involving a CD I released many many years ago… too long a story… really…)

Here is my last test with this cool shader !

Very cool!

His dentist needs a new nurse, tho

/Z

[gpepper]

Call me Zap, Master is just a title (In reality it’s a long story involving a CD I released many many years ago… too long a story… really…)

I think that you are all the same a boss !

Very cool!

His dentist needs a new nurse, tho

/Z

Maybe, He is too young to have any teeth…

[floze]

Not only that, it’s physics; short wavelengths (the blues) extinct faster than reds in a medium. Or something like that. Like how sunsets are red? I dunno I lost my particle accelerator.

Hmm… the short (blue) wavelengthes get scattered and reflected back easier by the atmosphere’s particles - the longer (red) wavelenthes either travel further or get absorbed; that’s why the sky (and also the sea) appears blue, or actually violet at daytime. And it gets red at sunset, because the longer wavelengthes dont scatter as easy as the short ones and the light has to travel a longer distance through the atmosphere - therefore relatively more red light but less blue and green light reaches the observer, making a nice romantic sunset.
So shouldnt an ocean look red from ‘below’ then?

Rayleigh scattering

[Jozvex]

Hehe, I think mother nature realised that would look too scary, so she cheated a bit for the ocean.

There really are great images in this thread!!

[Ridaq]

Hi all,

Im having a few prodlems with sss I cank seem to get the translucency working. Here is what my skin looks like when rendered…

And here is what it SHOULD look like.

I don’t know why there is a difference as they are both renders of exactly the same file! I downloaded one of GPEPPERS examples and rendered it out and yet I don’t get any translucency?!? Any ideas?

[gpepper]

Hi all,

Im having a few prodlems with sss I cank seem to get the translucency working. Here is what my skin looks like when rendered…

And here is what it SHOULD look like.

I don’t know why there is a difference as they are both renders of exactly the same file! I downloaded one of GPEPPERS examples and rendered it out and yet I don’t get any translucency?!? Any ideas?

!!! You’ve download one of my example and it don’t work ? strange !
The only reason that I see is that the lightmap is not created, that’s all…
Follow my tutorial, and it would work…

[elvis75k]

Call me Zap, Master is just a title (In reality it’s a long story involving a CD I released many many years ago… too long a story… really…)

ohhh… i’ve some kind of visual memory [size=2]and hey… maybe this small circle atop your name. You’re sweden… Wow some cool amiga demo scene coder!! But i was on ST many years ago… Don’t have deluxe paint Or maybe you’ve been a c64 cracker!! scuick … nostalgia.
Great to have you on this misss thread…

Please zap can y explain why if i optimize a scene in maya (sss with lightmap and texture assigned) i loose the connection and the texture?

Anyway man… you’re kinda strange…

-elvis
[/size]

[Ridaq]

Hi Gpepper,

I have indeed followed your tutorial (in every detail)and I’m still having problems. I think the lightmap has been created because in the script editor it says “Result: misss_fast_lmap_maya1” on completion of the render. And also I would have thought that without a lightmap I wouldn’t be able to see anything?

As I said the file is one of yours as I couldn’t get my own to work so I thought I’d give yours a shot and was still getting the same problem. :sad:

It can’t be a scale issue as you seemed to get great result… could it be a plugin I need to switch on ?

BTW I’m using a mac if it makes any difference…:rolleyes:

[gpepper]

Hi Gpepper,

I have indeed followed your tutorial (in every detail)and I’m still having problems. I think the lightmap has been created because in the script editor it says “Result: misss_fast_lmap_maya1” on completion of the render. And also I would have thought that without a lightmap I wouldn’t be able to see anything?

As I said the file is one of yours as I couldn’t get my own to work so I thought I’d give yours a shot and was still getting the same problem. :sad:

It can’t be a scale issue as you seemed to get great result… could it be a plugin I need to switch on ?

BTW I’m using a mac if it makes any difference…:rolleyes:

I absolutely don’t know if there is any difference with Mac ! Good question !
But I tried to render it again with my file and it works…
I tested it with Maya 7.0 and it works too…

[Ridaq]

Hurrah!!!

Success at last! It’s always the way, the most difficult and annoying problems often have the simplest answers. My problem was my path to the lightmap. instead of writing “\mySuperSSS” as posted by Jozvex in his great tutorial, for the mac it’s “/” or backslash then the path to your lightmap file.

Example: “/Users/Shared/mySuperSSS/”

And this is the result…

:applause:

thanks to Jozvex and GPepper for the tutorials and Help!!

Hope this helps out somebody else using maya on a mac!!

[Splin]

Hurrah!!!

Success at last! It’s always the way, the most difficult and annoying problems often have the simplest answers. My problem was my path to the lightmap. instead of writing “\mySuperSSS” as posted by Jozvex in his great tutorial, for the mac it’s “/” or backslash then the path to your lightmap file.

Example: “/Users/Shared/mySuperSSS/”

And this is the result…

thanks to Jozvex and GPepper for the tutorials and Help!!

Hope this helps out somebody else using maya on a mac!!

Glad you got it sorted! But…that 6:15…are those minutes? Isn’t it bit too much for simple sphere like that? What kind of cpu you have?

[Ridaq]

Hey Splin,

my system is a er… G4 ahem 400 mhz…

yeah I know she’s old but she’s been good to me

Gonna upgrade at the end of the year, gonna stay with mac tho…

[Splin]

Well a higher mesh resolution would help, but it looks like you have a little bit too broad specular and a little hair too much bump.

BUT this is a general problem in rendering, not just mental ray, not just this shader… if you use extreme bump, you will get fairly much light on polygons that are very nearly glancing the incoming light BUT as soon as the polygon starts to face away from the light, it is inherently “in shadow of itself” and hence receives NO light from that lightsource. So what you see is kinda a normal side effect of strong bumpmapping on polygon geometry. It’s just that the edge-enhanced specularity of the skin shader tend to accentuate this inherent problem.

/Z

Zap, I am also running into these problems. General workflow for avoiding such things would be then just to make your mesh more dense? Or are there more things what need to be concidered?

Sagroth, thank you a lot for your video! It is great and explains many things…now I understand it much better! Your shake flow is also cool…very wisely built! Thank you!