miércoles, agosto 10, 2011

Skin shader


External files:

Infinite's very popular model from http://www.ir-ltd.net/

Kzin's Skin SSS Bleeding Shader http://www.xsibase.com/forum/index.php?board=12;action=display;threadid=45395;start=0#msg287576


Well first, I want to thank Infinite an Kzin whitout their gifts to the CG community I could never get this shader look well. You can find in Infinite's web site, objs, texture maps, normal maps and displacement. Thanks, again.
This tests are made with Autodesk Softimage 2011 MR and I haven't used any kind of global illumination. I am not a shader expert and this is my first tutorial, just saying. I guess somebody could find it useful.

LET'S START

With the head obj in your scene just apply an architectural (arch) material and connect infinite's colormap to arch's material. I just set the reflection to 0 and I left everything by default.

Open the render tree and import Kzin's Skin SSS Bleeding Shader (SSS bleeding). Connect the SSS bleeding to Surface to base color in the mix 2 colors node and in the other color port put the miss_skin_specular. Mix with Add mode and maximum weight.

Now it's turn to plug the color map. You have to connect the color map in every SSS_color input in the SSS bleeding and put between the image and the node a color correction and balance. Just like this picture:

So, we want to turn the colormap to each basic color R G B, this way SSS bleeding will use this modified colormap to tint the SSS effect. These are my color I have used presets:

BLUE









GREEN









RED










SSS_bleeding_shader tweak:















miss_skin_specular values:












Create a SSS_lightmap: On rendertree menu>user tool>create SSS lightmap. This will bring you a new node that you have to connect it to SSS bleeding lightmap input and from that shader connect the output to material, like this:

Last step will be to add a type of displacement, normalmap or bump as you wish. In my case I rather use a normal map.

I have tweak a little the Kzan's shader by mixing differently red and blue channels. Clicking the E icon over shader node you can access to shader compound. I have changed slightly the color mix.

LIGHTING:

I have used a blue point light for the background and a white spot light as a key light and raytraced softshadows: 0.01 Softness and 8 Samples.

IMPORTANT: I have used a mia_photographic exposure (gamma 1.8) to tone and I have set the colormap to sRGB color profile. I have also connected the color map to illum_SSS_weigth on the shader but I guess I should connect a B/W image.

Skin shader from jordi agut on Vimeo.