Simulation - Animating with Blender: How to Create Short Animations from Start to Finish - page 280

Even though you use shadows with almost every object in your scene, you may fi nd the need to disable them
for strands. For the mother, shadows are clearly generated in the normal fashion for her hair, which can be
seen by examining any shot that the mother appears in. For the dogs' fur, though, the Shadowbuf setting in
the Material buttons had to be disabled. With the high strand count of the dogs' fur, the generated shadow
darkened their skin unnecessarily. I was unable to achieve acceptable shading results for the dogs with shad-
ows enabled for their fur.

The actual shaders that you choose, while important, don't have the profound affect that the Strand and Alpha
settings will have. The dogs used Lambert/Phong
for their fur, and the mother used Lambert/WardIso .
A little translucency was added ( Tralu: 0.22 ) so that
lamps behind a character's head could still contribute
to the strands' illumination.

Both the mother's hair and dogs' fur used a texture
mapped to Strand space for their colors. This works
exactly the same way as mapping a colorband's Alpha
to strands. Figure 14.77 shows a wild colorband applied
to the mother's hair in this fashion.

In the absence of any colors mapped to Strand space,
strands will take their color from their origination
point on the mesh. So, if you have applied a texture to
the mesh—a UV-mapped image, a procedural texture
or even vertex painting—that texture will color the
hair that grows from it. Figure 14.78 shows the mean
dog sporting leopard-like fur using this technique.

Figure 14.77 Nice hair, mom

This suggests a clever technique for carefully controlling
the color of strands for special cases. You can
independently control the colors of the bases
and tips of each strand by creating two sepa-
rate textures for the mesh, applied in Orco or
UV space, and separating them in the texture
stack by a simple white-to-black blend tex-
ture mapped to the Strand space and used
as a Stencil . Figure 14.79 shows two differ-
ent textures applied separately, then stenciled
together along the length of the strands. The
texture for the strand bases is a black and
gold speckling. The tip texture is a white and
red. The effect is most obvious in the longer
strands on the tail and the top of the head.

Figure 14.79 Blending between two
textures along the length of a strand

Figure 14.78 Species confusion