Before texturing the model, you will need to create a nice shader that mimic skins, with a Subsurface Scattering look, in order to have a better feedback. For that purpose, you'll use a new type of ZBrush 3 material; a Matcap material. It can be created in two different ways: By using a Ball picture rendered in a 3d application; or from within ZBrush. Using a good material from this point will also give you a good idea of what the model will look like in a final render.
Setting up a Standard Shader:
If you can't use an external app to create a Shaded ball, you can also arrive at the same result by using a standard material. In The Material Palette, select a DoubleShade Material, and set it as shown. Now, draw a sphere on the Document, to preview the material.
Open the Light Palette, and adjust the lights to get a nice result. Four sun lights should do the job.
Select the MRGBZ Grabber tool. In the Tool's modifier's palette, make sure that Auto Crop is on, and drag a selection on the document around the Ball. A copy of the Ball is stored in the Texture Palette. Change the specular settings of the material to have some variations of the material, and grab more pictures. Save all the pictures, the lights and your document if you want to make further modifications of the material.
MatCap, a new way to shade your models:
The Sphere on the left is rendered in Mental Ray, using the MiSSS Skin shader. The subsurface settings were adjusted so that there are no dark zones, and so that the translucence is really visible.
Select a MatCap Material in the Material Palette, like the Red Wax, open the Modifiers Sub Palette, If the Material Palette is greyed, select a 3d Primitive tool. Some tools don't allow you to modify the Material settings. Click on the Material texture 1 Slot at the lower Left corner, and select the one of the Ball pictures grabbed previously, or a picture rendered in a 3d app.
In The Colour Palette, select a brown colour, and then click on the Base Colour Modifier. It will bring in the pink color of the material when you will paint it.
The Eye:
We're going to model the eye, now. Select a Sphere 3d Primitive, and set the HDivide and VDivide to 24, in the Initialize SubPalette. Convert the Pritive to a Polymesh 3D.
- Select the Move Edit Brush, click on a Pole vertex to shape the Iris, then, hold Shift to constraint the translation to the vertex normal.
- Hide the Eyeball, except the Iris, and do a Crease, and create a new Polygroup from.
- Unhide all, and subdivide the eyeball up to level 5.
- That's all for the modelling, now.
Texturing the Eyeball:
- Now, switch back to the Eye model, open the Tool - Texture subpalette and activate the Colorize option. You don't need any UVs on your model, as the colour is actually stored on the model vertices.
- Deactivate the Zadd option, and leave only the RGB activated.
To paint a model, you can simply use the same Standard Edit Brush as to sculpt. You only have to choose between different Alphas, different Strokes. And pick a colour in the Colour palette. To pick a colour from your model, of simply from the canvas, click on the Colour Palette, and drag the cursor to the area of the document you want to sample. As you created earlier several Polygroups, these will allow you to mask easily the white of the eye, and to bind the texture of the iris.
The Iris has a specific radial pattern. To reproduce it more easily, activate in the Transform Palette the Radial and Z Symmetry, and set the radial count around 25. When the basic texture is created, you can deactivate the symmetry, and continue to detail the eye
