New Basic Shader

[Taron333]

I'm preparing the docs right now! Sorry for the delay! It all works, I will show you! No worries....my bad! Too busy coming up with some new things, but I apologize for dragging behind on those docs!


Ah..but just as a quicky!
Xtended radiosity is the subsurface continuation of the radiosity and only works when radiosity is turned on, of course. However, you have to determine an offset or better " INSET" and a "DEPTH" which is larger than the inset in order for it to show!

examples:
X depth = 0.2
X inset = 0.05

ALSO, you should have some diffuse level set, if it's the only object for instance, because otherwise there would be no radiosity seeing anything....
Try it with also an environment turned on...like a gradient slope for instance! It's mainly designed for use with radiosity only and works best there! But it works anywhere!

I'm implementing a full standart SSS now, too...classical and maybe one with a twist! :)

[SergO]

Thanks for the tip!

But im having a hard time getting it to work in conjunction with regular lighting sss. As soon as I put Inset I get some big banding artefacts with regular lighting sss.
Using radiosity sss by itself can also create dark artefacts, because of its "Inset" nature I suppose... in some areas like small features in ears etc, the inset way of the shader is not well suited for it and can create unsighly dark areas. I'm thinking of blending two shaders to alleviate that (maybe using lighten mode), but of course that means twice the render time.

Regarding the color feature, there are a couple of wee bugs with it ;)
Extension Amount kills it... but I like using lots of amount! 5 or 10 is common for me.
Using negative fresnel kind of inverts colors, so if your using red it makes a kind of green.

I'm very glad to hear that you have plans to implement other types of sss! :)
Its not that this one isnt good! It's great for many, many, situations and its very very fast. What I dont like about it is that I find that this kind of sss (or volumetric translucency) is a very hard look, or CG-ish look, In my quest for photoreal skin It's very dificult to get the natural organic look I want with it. I suppose it is because it still cant do soft shadows, which of course is kind of contradicting the translucent effect it is trying to create.

I would really really love to have a shader like this: :D http://www.happyship.com/lab/chanlum/documentation/index.html
Please please please :)
All it does is blur the diffuse lighting... exactly what is needed for shallow scattering, like that in skin.

Also, this excellent tutorial on skin sss surfaced a few days ago, its quite informative even if you dont use Mental Ray:
http://www.lamrug.org/resources/doc/sss-skin-shader-tutorial.pdf

Cheers

Serg

[Taron333]

Hey Serge, you're exactly right. The volumetric translucency is simply the fastest implementation of such an effect and I initially came up with that over four years ago. I didn't get to implement the scattered or multi-sampled render yet, but that's what essentially gets us to the full SSS. I'm not sure about what it is, that you're doing to require such high strength levels, but I'll see to it to find some nice control of the color mode for you. Shouldn't break, that's for sure!

So thanks for your research there and the great feedback! It's much appreciated!

Taron

[SergO]

Hi Taron,

I use lots of "Xtension Amount" because it prevents the diffuse illumination from reavealing itself in shadowed areas. I prefer the shadow to be illuminated by sss only.

Cheers

Serg

[chikega]

Thanks Taron for looking into this - SergO has described the same issues I've run into - Most notably the banding that appears, reminiscent of my earlier studies with G2 (http://www.3ddmd.com/test_renders.htm) last year in the pursuit of realistic SSS effects.

If we're able to have an option for true volumetric translucency a la OGO_Hikari (http://www.asahi-net.or.jp/%7Epq1a-ogs/block_e.html), then we would really be talking.

http://www.asahi-net.or.jp/%7Epq1a-ogs/block02.jpg

Having an object show up within a translucent object would allow something like this:

http://www.splutterfish.com/sf/FeatureGalleries/sss18.jpg

Or this:

http://www.splutterfish.com/sf/spluttergallery/pics/179.jpg

[chikega]

But if nothing else, I would be happy with soft shadows, like these demonstrate:

http://www.splutterfish.com/sf/FeatureGalleries/seahorse.jpg

http://www.splutterfish.com/sf/FeatureGalleries/brazilnew3.jpg

http://www.splutterfish.com/sf/FeatureGalleries/wax_shader_tamer_02.jpghttp://www.splutterfish.com/sf/spluttergallery/pics/102.jpg

[Julez4001]

http://flarenova.com/Msx/msx_sflow.htm

Hey Taron, I used a metaffector to make a cheap SS trick, is that how u made the red cheeks on your doll?

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