For the last few days I’ve been testing Cycles, which is a fairly a new unbiased CPU/GPU path tracer renderer for Blender, available alongside Blender’s internal engine. When combining its speed with the flexibility of Blender’s Shading node editor, it becomes a serious contender to Vray, Arnold, Keyshot, Octane or Corona, plus it’s Open Source and free.
While Cycles comes with basic shaders like Diffuse BSDF, Subsurface BSSRDF, Glossy BSDF (including the GGX Shading Model), etc, to create realistic materials you have to combine these together into more a complex Shading Group. Once created, this Shading Group can be easily reused and shared between scenes, and can be controlled with a set a variables that you decide to expose to the end user.
In this example I am mixing together two Subsurface shaders, a Diffuse shader, and a GGX Gloss shader. To get a red scattering lobe, I am overlaying the color inputs of the SSS shaders with two complimentary colors, slightly weighted towards red, and I am using two different scattering radiuses to simulate two skin layers. For the specular component I am remapping the fresnel node to allow individual control over the F0 and F1 parameters.
I would like to thank Ten24 for providing this model.
Skin Shader: Blender_SSS_Skin_Shader_Undoz.com.blend - I’ve added a simple scele with just the skin shader so you can use it with your own models.
Skin Shader and Model: 3dscanstore.com was very generous to give away a Blender Render Scene complete with a free Head Scan and the Skin shader above. You can find it here: http://www.3dscanstore.com/index.php?route=information/information&information_id=16