Sub surface scattering again...

[j meyer]

  Cool,maybe you don't need a map at all for animations then.
And for stills,too.
Will have to try with a head with and without UVs.

[Hannes]

I guess for the Ten24 Head we'll need at least additionally some kind of a simplified head mesh for light blocking with almost no ears or nose to let the light through there.
Or a simpler version: Adding just an oval sphere inside that roughly fills the detailed head mesh PLUS the depth map. Thus there wouldn't be glowing ears without light shining from the back side.

[j meyer]

Good idea,definitely worth a try or two!

[Hannes]

I created a simplified and slightly smaller version of the detailed scan head, cut off his ears and nose (guess I cut off way too much of the nose as you can see in the second image: Rudolph the red nosed reindeer! ), and placed it inside the original mesh. No depth map used. The appearance of the translucency is controlled by the amount of light that hits the head from behind and the side.
No constantly glowing ears anymore.

[Oshyan]

Damn you guys, this is pretty cool.

- Oshyan

[TheBadger]

Damn you guys, this is pretty cool.

- Oshyan

I think you mean, "Damn (period)", then, "you guys this is pretty cool."



@hannes, PMed you. Send me your email
J, send me your email too.

I have something from a ways back DandelO worked with me on that may be fun for you to toy with.

[bobbystahr]

I created a simplified and slightly smaller version of the detailed scan head, cut off his ears and nose (guess I cut off way too much of the nose as you can see in the second image: Rudolph the red nosed reindeer! ), and placed it inside the original mesh. No depth map used. The appearance of the translucency is controlled by the amount of light that hits the head from behind and the side.
No constantly glowing ears anymore.

Does kinda jump out at ya don't it...but great discovery work on this...you impressed Oshyan...that's sayin sumpin....

[Matt]

Keep pushing the limits! What are your GI cache settings Hannes?

Matt

[TheBadger]

Perhaps this is a pointless question, but is there a word that describes the effect that we are after here in the real world? I mean, the fact that you can hold a flash light against your hand and see light through your skin, what is this called in non CG real world terms?.. I was thinking that people who study jelly fish would have a word..?

The reason I am asking is, How do you determine what is a "real" amount of light, that should pass through, what thickness of skin?

Because, this seems to work more or less. So how do you decide when it look real? Other than saying it looks real, or real enough.

Basically, how can we say in any sort of verifiable way, that it is visually correct?

[Dune]

Super guys! I mean; Super guys and super, guys! But I don't think you should cut the nose off, ears are very thin, so yes, but the nose is very translucent in your example, Hannes. Doesn't a map work easier than another object? Just map the thinnest parts white,  the rest grey-black.

[Hannes]

1.) Thank you Oshyan!

2.) Done, Michael

3.) Yes, I'm proud, Bobby 

4.) Glad you like it, Matt. The GI settings are quite high to produce a clean image (depending on the size - the smaller the image, the higher the settings have to be). For my Rudolph I used 5 for each GI cache detail and GI sample quality. Takes a bit longer to render, but it's worth it.

5.) Michael, I guess you have to ask a native english speaking guy what the right expression would be. I don't even know a german word for this (Jochen? What would you say? Lichtdurchlässigkeit? Unterhautlichtstreuung? That sounds really weird!) Is there the expression sub surface scattering in the real world?
I'd say it looks visually correct, when you don't have the impression that something is wrong compared to reference images (photographs). Everything is faked here, so let's try to fake as good as we can.

6.) Ulco, I know he looks as if he had a lightbulb in his nose. I had no success yet to use a map alone without having the brighter parts of the map glowing constantly.
It's interesting that the "inner head" can be made invisible and even set to not casting shadows (!) for keeping the object from poking through accidentally, and still does his job. Sounds illogically, but as long as it works...

[j meyer]

Yeah,congrats Hannes,your idea works really well.I've tested it,too.
Made an extraction of the mesh inner and tried it with and without
additional map,works great.And I can also confirm that it works with
the cast shadows disabled and so on.

I only know the term subsurface scattering never heard or read another one.
In german it's Volumenstreuung according to the omniscient web.

I found a lopoly version of another freebie scan head (9525 polys) and
tried it with that and it works,too.As a general rule of thumb you can
say,if the model is good enough for close ups without tranlucency than
it's good enough for translu also.
But you have to keep in mind that - as far as I know - the Daz models
have separate eye parts and teeth,an inner mouth and so on and you'd
have to take that into account when applying this method.


Edit: glad to see that I'm not the only one remembering Rudolph!

[Hannes]

OK, here is a new Rudolph with a new inner head. The inner head's nose hasn't been touched, but I cut off his ears. Then I extruded the faces with a negative value (does that mean I intruded the faces?) However I made it slightly smaller so that it fits into the original head. The nose in the second image is still a bit glowing, but I think it's OK.

[bobbystahr]

Well done, much better.

[Matt]

Perhaps this is a pointless question, but is there a word that describes the effect that we are after here in the real world? I mean, the fact that you can hold a flash light against your hand and see light through your skin, what is this called in non CG real world terms?.. I was thinking that people who study jelly fish would have a word..?

I would call it 'translucency' when talking to non-CG people.

Matt