Simulation - Animating with Blender: How to Create Short Animations from Start to Finish - page 271

Child strands are what the renderer actually sees
and draws. Children are generated at render time
(though they can be shown in the 3D view) and
can be grown either from the faces of your model
based on vertex groups or in a radius around par-
ent strands. Figure 14.59 shows the mother's child
strands. Child strands interpolate their characteris-
tics from the parent strands around them.

The best way to use the system is to create and
groom Parent strands, then have the renderer grow
child strands to fi ll out the system.

Setting Up and Adding Parent Strands
for Grooming

Figure 14.59 Child strands

The fi rst thing you need to do is to defi ne your overall hair/fur area with a vertex group. An easy way to do
this is to begin with a selection in Edit mode, like Figure 14.60, create a new vertex group, and assign it with
a Weight of 1.0 . Then, using either Ctrl-Tab or the object mode menu on the 3D view header (Ctrl-Tab
will not work from Edit mode), enter Weight Paint mode and soften the edges of the selection, as in Figure
14.61. This area is where the child strands will eventually grow. In the Vertex Group section of the Particle
buttons' Extras panel, set the property to Density , and choose the created vertex group in the pop-up menu
to the right, as shown in Figure 14.62.

Parent strands can be added in one of two ways. For an even distribution of parents within the growth area,
you can just set a particle number in the Amount fi eld on the Particle System panel, as in Figure 14.63.
Change the system type to Hair instead of Emitter , and give a value to the Normal fi eld so that the hair

Figure 14.60 A vertex group for growing hair begins in Edit

mode with a selection

Figure 14.61 The boundaries of the group are softened in

Weight Paint mode