#59: SHADOWS & LIGHT (Vue)
#58: ADVANCED DIRT MAPPING (Vue)
#57: SSS IN VUE 9, AND THE "SPECKLE" PROBLEM
#56: THE DEVIL IS IN THE DETAIL OF ART
#55: FIXING POSER CLOTHING
#54: MAKING "FOREST WAR - GOBLIN SHAMAN"
#53: MAKING A STUDIO RENDER FOR VUE
(and other apps)
#49: NEBULA MKIII (Vue)
#48: RENDER SETTINGS FOR VUE (Vue)
#47: POSTWORK - MAKING A RENDER INTENSE (Any)
#46: MAKING RIVERS THAT FOLLOW TERRAIN HEIGHTS (Vue or Bryce)

SSS IN VUE 9, & THE "SPECKLE" PROBLEM


Having just got back into Vue after a few months of hiatus, meh, atrocious weather and thus makes my health suck, lol, I started getting back into the swing of things with Vue :)

So, taking a previously built model into Vue9 to really get to work on this new version properly, I started messing around...and found some odd things with this character model after I had rendered it...and also tweaked around with settings to get SSS working nice to get good looking skin. SSS = Sub-Surface Scattering, the effect you get like with milk, marble jade and skin, when light bounces around inside the material itself.

To begin with, getting basic SSS, or as Vue calls SSS "Translucency", skin set up. Now these are MY settings for it, by all means try your own :)
Some sources using darker "Absorption" colours, for example


SETTINGS FOR SSS SKIN IN VUE 9


To see WHY you should consider using SSS for skin, please roll your mouse back and forth over the image below, to see the effect, with and without it!

Quite a difference, eh? :)

Where the problem came in was when I first started off, I noticed an annoying problem:

the skin of the model kept having this bloody annoying light coloured "speckling"!
Take a look at this picture to see what I mean:

SEE THE SPECKLES ON LEFT OF FACE?


I had seen this before, or similar issues, in other versions of Vue, but why it occured is simple: it's because I had used Sub Surface Scattering in the material

What caused the problem though? The answer's a bit complex but has a VERY simple remedy:

when you import a Poser character and add SSS to a skin material, to make it appear glow in that healthy way skin really does...you often have problems, caused typically by hair, eyebrows, eyelashes going all "Solid black" without any transparency, or other weird issues, and find you have to "split" those parts off the model which have SSS, entirely

You use EDIT on the model, and SPLIT, tearing it apart based on materials, then select the offending hair or other item, move it into it's own group, then select the model's body parts with SSS, bar the offending item, and "WELD" them together again.

And here's mostly where the "speckle" problem comes in! (though it can still show up in a model that has not been broken apart in this manner)

Subsurface scattering mimics how light bounces through an object that is not totally opaque, like, skin, marble etc. However, real objects are not made of mere cyber stuff, Poser and other 3D models are just illusions, imagine paper thin constructs that, as long as all the edges meet, are "solid" as far as your computer is concerned
and hey I'll avoid going all esoteric on you about "string theory", nuclear physics and why real world objects are 99.9999% empty, too, lol :P

But if there is the slightest gap in your 3D model...it is no longer solid, it is merely a "skin" (NURB modellers will understand this best I think), and that's where the problem comes in.

As SSS relies on light bouncing around in a SOLID object...it goes nuts! It's like instead of bouncing around inside say, a jade figurine, it's bouncing around inside an empty sack and goes all wonky, causing the speckles.

Fixing it though, couldn't be easier! ;) just turn on "Use infinitely thin surface model" as I noted in the image with the settings at top of the page! ;)

So, in general, if you use SSS on Psoer models, and maybe others, turn on "Use infinitely thin surface model" if you have any problems

this is how the figure looks when that setting is turned on, getting rid of the speckles

 

SPECKLES GONE BY USING "INFINITELY THIN MODEL" SETTING

I hope you find this of use! :)

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All original art, writing on this site, copyright of Steven James, "Silverblade the Enchanter" ©2012