slimy tentacles / SSS Research and Materials

[smileman]

Oops, take a look and try !

[WingedOne]

But, as i can imagine, Zbrush cannot dirstort refractions..

ZBrush can distort refractions if you turn down the RGB level of your tool and use the "refract" slider in the draw menu. A refract of 0.33 is equivalent to an ior of 1.33 (water) and 0.5 is equivalent to an ior of 1.5 (glass).

Of course you'll need a background to draw over or else you won't have anything to refract.

You can then use the blur brush to blur your refractions.

Maybe someone can try that as a starting point?

I don't have ZBrush with me at the moment.

[slocik]

Oops, take a look and try ! [/ATT]

smileman, i think the point was to make fake sss, not a cool glowing material :|

[smileman]

Better ?

[smileman]

little question, how to do transparency between two layers in Zbrush ? I'm stupid !!!!!

[TVeyes]

That looks very good Thomaskl. I tried to replicate some of the render effects but it is simply not possible to match a physically accurate render engine using the ZBrush renderer, at least not without some tricks and some 2D editing. But on the bright side the following picture was completed in ZBrush in just under an hour, including a slight color and levels adjustment in Photoshop. What was your render time again Obviously I do not have quite the same quality, but still.

The key to the following render is not the material, although it of course has an effect, but the use of baking the material/render generated colors multiple times with tweaking of the material and lights in between. It is a bit difficult to explain but I hope the step by step below is clear enough.

Jantim: It is possible to have an in focus section at the middle using ZBrush's Depth Cue. Take a look at the curve below.

[Thomaskl]

It`s so damn cool to see, how you guys are are trying to approach the perfect SSS feel in Zbrush.
As i started thinking about doing an SSS Setup, i was unsure about the way, vray handles SSS, because it is based upon blurred refractions, internal fog and the IOR of the material. Im not sure, if this is the correct physical way of simulatiing a real light distribution under a surface, because i don`t own the brain, which is really needed to understand the complex theorie behind this special surface effect. My intrest resultet out of a little anciety of SSS, because the whole CG Community is talking about that for a couple of years, and i, for myself, wasn`t able to get the plot in depth. So, i always was a little afraid of that phenomenon.
The ways, the postet materials are working have one thing in common. They are all workarounding that "voodoo"-CG SSS Thing. I do like Jantims approach, because it does not need so much post work, as the approach TVEyes uses for his final result. At the end, you could render the image with any kind of linear material and do the whole SSS Effects in PS by painting. But respect and thx for the work you invested in this version. It`s a cool result, man !

I had a hard day animating, and i am quite tired now (had some drinks, too..:-D )

Have fun !

Thx a lot !
Regards,
Thomaskl

[TVeyes]

Don't get me wrong. I am also praying that Jaintim can come up with a material that can do it in 1 or 2 passes ( pretty please Jantim, you don't need to sleep this weekend ). But having said that, the multiple baking method is not so difficult, except if you have had a couple of drinks Thomaskl

I think "drinks" was the magic word. I am off now. Have a nice weekend everybody and I hope you come up with some cool materials/workarounds to the SSS effect.

Ron Harris: Cool picture. I really like the effect of both versions. As you can see from my picture I would prefer some more contrast but the general color range looks great.

[smileman]

TV eyes thank you!

[WingedOne]

Here's an experiment I just tried using the technique that I mentioned up above (if you set your RGB to less then 100 in the draw menu, a slider for refraction becomes available).

I duplicated the background layer and rendered it and baked it before placing the object on it. Then I went back to the original layer for rendering after the object was placed on the duplicate layer. Otherwise, my object wouldn't be casting a shadow onto the ground.

Preliminary picture with refraction only (all ambient, no diffuse, some specular):



Here I blurred the refraction with the blur brush and then fogged it in a little (mostly in the middle) with the simple brush. I decreased the ambient and raised the diffuse levels a little bit:



Here's the final render. For the main ingredients of this material I raised the anistropic diffuse up to 0.6 and the occluded ambient up to 0.5. I used a light blue color for colorize ambient plus a tiny amount of cavity shading to bring out the details a little bit.



My material is enclosed in the Zip file attached to this post.

[stalsby]

nice work!!! its quite confusing! wish i new how to do stuff like that!!!!

[jantim]

Well Thomaskl..see what you did !..now everyone's weekend will be spend tweaking materials and rendersettings

DarthWayne : you need a backlight and/or a radial light to get the best effect of SSS..but remember the material-settings "mimic" the SSS-effect, that is also its limitation !

Wingedone : "Cool'...your material looks like transparent wax.

marcus_civis : I never used glow in my materials-good idea-i have to think about it !

smileman : i infected you wit the material-bug -or worm, in this case-as well

TVeyes : Man , you seem to know every technical aspect of this program
I tried to get the effect of the focus in the middle by doing a two layer render and baking the first one..but then the "depht of field setting" of the second layer just ignored the "baked"pixols of the first render and blurred the whole scene..
I someone can create a SSS-material it must be done by writing a new code for such a material..i'm just a button pusher and a setting adjuster
and i don't think it can be done with the setting of the materials to this point!



Oh yes ,stalsby..it is confusing..in the beginning..and even after a while !

jantim

[slocik]

Cool, i didnt know you could do refractions in zbrush Think i will find this usefull one day this thread roks

[jantim]

marcus_civis...using glow in your material was a nice idea...



and in this render i pasted a "glow" channel and a....can u guess ?



jantim

if u want to try...here's the material

[marcus_civis]

jantim,
Looks great! Environment reflection?