Digital Art Zone

Here’s the thing.  I’m trying to simulate SSS in Bryce and what I need are two models that fit almost exactly inside one another without the mesh’s colliding and the inside one showing outside the other.

I can get light to scatter into the skin, but to avoid it making the complete transit across the body, another close fitting body inside the first body would act as a suitable absorber - since SSS is not a native function of the Bryce render engine, some work is required.

You can see the effect on this simpler model of the nice snake monster.

But I’m having problems with Vicky due to her more complex geometry (see other images)

So, is there any way in DS that I can take my model of Vicky and make her slightly smaller - I suppose “skinnier” would be closer to the truth - all around.  I need her to shrink in such a way that she will fit inside herself exactly, to a depth of about three to four mill, in real terms?  This would negate ears but not fingers.

Idea’s welcome.

Oh, please note, I am a total DS noob.  So if this is an obvious built in feature, I really don’t know anything about it!

I can’t recall - does Bryce do displacement? If it does a little negative displacement (-.4 would be 4mm) on the inner Vicky would move her in away from the outer Vicky.

Richard Haseltine - 25 November 2012 05:37 AM

I can’t recall - does Bryce do displacement? If it does a little negative displacement (-.4 would be 4mm) on the inner Vicky would move her in away from the outer Vicky.

Yes that would be great, but don’t get me on a displacement rant really!

Really don’t.

I need a solution from within DS to then bridge over to Bryce.

In DS4.5 and I think in DS4, “Create” (top Menu bar) a “Geometry Shell” of the posed figure. Select the Shell and in the Parameters Pane change the mesh offset to suit. You will have to copy and paste the textures on to the shell but that is easy, just select all of the figure’s surfaces in the Surfaces Pane and copy, select the shell and paste.

I don’t have Bryce installed at present but it did work as a OBJ export and when I reimported back in to Daz Stuio I had one figure inside the other with all the surfaces textures in tact for both meshes.

Szark - 25 November 2012 07:59 AM

In DS4.5 and I think in DS4, “Create” (top Menu bar) a “Geometry Shell” of the posed figure. Select the Shell and in the Parameters Pane change the mesh offset to suit. You will have to copy and paste the textures on to the shell but that is easy, just select all of the figure’s surfaces in the Surfaces Pane and copy, select the shell and paste.

I don’t have Bryce installed at present but it did work as a OBJ export and when I reimported back in to Daz Stuio I had one figure inside the other with all the surfaces textures in tact for both meshes.

Thanks Szark!  I will go look at that.  No problem about the textures, I don’t need the textures, the “absorber” only stands in for subcutaneous tissues so can be matt or zero depending on the light.

OK that’s close, very close to what’s needed but…

On shrinking the mesh using mesh offset the ears and toes turn inside out and get bigger than the original model.  What I need is for things once shrunk beyond overlapping to just vanish - is there any option to make things just stop once they pass the point where they get turned inside out?

Sorry David you got me there.

To be honest I think it is meant to be used with small values as the same happens with Geneisis….never using this with a high offset I didn’t know it did that, sorry. How far do you need the offset to be for what your trying to do in Bryce. I thought you wouldn’t need much, like -0.10

Szark - 25 November 2012 09:00 AM

Sorry David you got me there.

To be honest I think it is meant to be used with small values as the same happens with Geneisis….never using this with a high offset I didn’t know it did that, sorry. How far do you need the offset to be for what your trying to do in Bryce. I thought you wouldn’t need much, like -0.10

Ideally enough to make the ears “vanish”.  The light should be able to transit through the upper lays of flesh, in and out, but not make the journey right the way through the model.  A skeleton would do… sort of.  But I think that the bones would probably cast too obvious a shadows on the inside of the skin.  It’s a fiddly project because it seems viewers are exceedingly sensitive to minor changes in the way skin looks and so this leaves little room for error in simulation.  A glance at most renders of human figures is usually enough to determine that it is indeed a render and not a photo - even when photos make up part of the skin material.  Here are some luxrender renders http://browse.deviantart.com/?q=luxrender just focusing on the skin here.

A little bird told me that Luxrender does not have SSS.  Which got me thinking…

I don’t use Bryce but could you use a mask [either in DS or Bryce] on the inner Vicky to get rid of just the ears so the the secondary Vicky’s ears are then hollow, allowing the back lit SSS to work?

Do it the other way around…the outer Vicky being the geo-shell, with full textures applied.  That way the offset shouldn’t turn things inside out.

Another option that is often used when faking SSS, is to use a control map…not sure what the options in Bryce will be for this kind of map, though.

Interesting ideas… OK here’s one with just a couple of black spheres stuck inside her bonce.  Just to show that the absorber mesh doesn’t have to be terribly accurate, it just must be smaller.  Because SSS is not a native Bryce function I’m trying to control the effect I’ve got with geometry.  This is not idea, but better than no SSS.

There are ‘earless’ morph packs around…you may want to try one of them to get rid of Vicky’s ears, before creating the shell.  Also, if the feet aren’t in the shot, just hiding them should work, or a ‘sock toe’ morph/prop.

Better still…why not shrink/create a shell, & do a negative offset for a body suit?