Exercise: Modeling Patch-Based Hair
Here's a way to create reasonably good looking hair using patches without too much fuss.
First, you need to start with a head (see Figure 1). This can be of any type of geometry. Create a long, thin patch approximately the length of the hair that you want to create (see Figure 2). Don't make the patch too wide because you will be using several of them to fill out the hairdo.
Figure 1 This character needs a new 'do.
Figure 2 Start with a long, thin patch.
Next, you'll have to create some hair textures to put on the patches. These textures will resemble locks of hair. You can create these by using a photographic or scanned reference. Create two maps, one for the hair and one for transparency. Combine these to create a simple material. When applied to the patch, this will create a nice lock of hair. Create several textures with varying densities of hair (see Figure 3).
Figure 3 Create a few different hair textures, from dense to wispy.
When you have the textures, creating the hairdo is simply a matter of sculpting the patches to create individual locks of hair (see Figure 4). Duplicate these patches, and layer them on the head to create a full hairdo, resculpting the patches to conform to the head and hairstyle (see Figure 5). For extra realism, you can arch the patches in to almost a half-tube shape to give the impression of thickness. Use the denser hair textures on bottom layers and the wispier textures over the top. Adjust and sculpt the hair until you get the right look (see Figure 6).
Figure 4 Sculpt the patch to fit.
Figure 5 Repeat this for many more patches. This hairstyle took about 60 to 70 patches.
Figure 6 The finished hairstyle.