Note: This tutorial was created for Toolbag 2. Some techniques offered in this tutorial remain very helpful, however, shader setup and user interface may not apply directly to Toolbag 3.

Watch as Joe Wilson and Lee Devonald demonstrate how to set up a character, including the skin shader, eyes, hair, lighting, camera, and depth of field.

Thanks once again to Yuri Alexander for allowing use to his art content. Download the scene featuring Yuri’s girl here. All rights reserved; Yuri’s content is being provided for educational use only.

Thanks to Ryan Jackson as well for allowing us to use his sweet alien guy.

Quick Reference

By Joe “EarthQuake” Wilson
I realize you may not have time to watch a long video, so I’ve also put together a quick reference guide. Mouse over the thumbnails to view a quick demonstration, and click for an enlarged view.

Skin Shader

Its important to note that human skin is rather dense, so you may want to use fairly low values for some of the skin shader parameters. For instance, values which are too high for the subdermis scatter and shadow blur settings may make your character look waxy.

Subdermis scatter defines the color and intensity of the skin effect. Mask non-skin elements with a black value in the subdermis map (RGB or alpha).
Shadow blur controls how much blur is applied to the shadow pass. Try to find a value that blends smoothly from lit to shade while retaining the shadow shape.
Normal smoothing blurs the diffuse lighting contribution to give the surface a soft, fleshy look. It does not affect specular reflections.
Occlusion blur controls how much blur is applied to the ambient occlusion pass (both the real-time effect and baked). It is useful for softening the look of the occlusion effect.
Translucency defines how much light scatters through the surface. Brighter values in map define thinner surfaces (ears, nostrils). Use Knald to bake a base map.
Fuzz adds a diffuse Fresnel-type effect to mimic micro hairs on the surface of the skin. Fuzz works best with variation in the texture map to break up the effect.
Sky translucency defines how much the ambient image based lighting from the sky light affects the translucency. Usually a low value is best.
Fuzz scatter controls how wide or narrow the fuzz effect appears; in other words how much the fuzz effect spills over from the edges to other areas of the surface.
Translucency scatter controls how far the translucency effect bleeds out of the shadowed area and into the lit area.
Fuzz occlusion defines how much shadowing and ambient occlusion mask the fuzz effect. Should generally be set to a high value like 1.0 for best results.

Eyes, Additive blending and Parallax Mapping


The best way to create convincing eyes in Toolbag 2 is to use the dual layer method, which involves creating a base mesh with a standard material, and a duplicate mesh with an additive material. This allows you to use unique normal, gloss and spec maps for each layer.

Note: Something I failed to mention in the video is that the wet layer normal map should be perfectly smooth for the lens itself (some variation on the rest of the eye is a good idea though).

Parallax mapping
can be used to fake the refractive qualities of the eye’s lens. Load a height/displacement map with darker values for the pupil.
Parallax depth controls the strength of the parallax effect. Make sure to set the depth center to the mid or zero-point value of your displacement map.

Hair, Transparency and Anisotropy

The first thing to do when setting up hair is enable transparency in your material. The transparency map is automatically loaded from alpha channel of your albedo map.

  1. Cutout, a.k.a. alpha test provides basic on/off transparency, black values define fully transparent areas while white values define opaque areas.
  2. Dithered provides soft blending, and is the best method for hair. It will look noisy in the viewport, however it looks much better when rendered out (render at 2x to further improve quality).
  3. Additive, shown above in the eye section, renders the specular pass additively, which is great for eyes, glass, etc.
controls the strength of the anisoptropy effect. With a value of 0, the highlight is round, while a value of 1 stretches the highlight along the anisotropy direction.
Anisotropy direction defines the direction which the highlight conforms to. Line the anisotropy direction up with your UV direction, or load a custom direction/flow map.
Refraction shift
controls how far the secondary highlight is shifted from the primary highlight. This is essential for reflections for hair materials.
Secondary gloss defines how rough or smooth the secondary highlight is. Make the secondary highlight a bit rougher or glossier for extra variation.

The skin shader can be used to soften the overall lighting and shadows, and the secondary specular slot can be used to add an additional offset specular highlight (generally tinted the same color as the albedo).

Other Uses

Stylized, unrealistic and otherworldly effects can be achieved by by cranking up the skin shader settings and using strange colors in the subdermis and translucency maps.

The skin shader can also be used to create translucent materials other than skin, such as milk, wax, and certain plastics. The possibilities are endless, so get creative and come up with your own unique effects using the skin shader!