Hair from Guides Operator
The Hair from Guides operator generates dense hair from a set of guides. It takes the sparse guides you have shaped and interpolates between them to produce the full-density hair that is rendered. This is the operator that turns a handful of control strands into the hundreds of thousands of hairs in a finished groom.
Distribution and count
Like Guides from Mesh Operator, this operator distributes hair roots across the surface, with the same family of methods:
- Uniform
- Random (area-based)
- Random (face-based)
- Random (UV-based)
- Vertex
- Guides as hair - convert the incoming guides directly into hair without generating new strands.
The count parameter sets how many hairs are produced. Because the hair roots are placed independently of the guide roots, you can keep guides sparse for easy editing while still generating very dense hair.
Guide proximity
With Use Distance on, only hairs within Distance of a guide root are generated, so hair grows around the guides and nowhere else. Falloff adds a soft edge beyond that distance: between Distance and Distance + Falloff the hair thins out gradually until none remains, and zero keeps the hard edge. Falloff is a surface-varying parameter, so a map, a channel or an expression can scale its width over the surface, and its curve sets the hair density across the edge, from the distance on the left to the end of the falloff on the right. Which hairs survive inside the edge is decided per hair, so the result stays the same between evaluations and preview fractions.
Interpolation
The shape of each generated hair is blended from the nearby guides. Even, well-spread guides give the smoothest interpolation; clustered or uneven guides can produce artifacts. If the interpolated hair does not follow the guides as expected, revisit the guide distribution rather than adding more hairs.
Placement in the stack
Hair from Guides usually comes after guide creation and guide styling. Styling operators placed above it act on dense hair; operators that require guides should sit below it. See Hair and Guides for why this ordering matters, and The Operator Stack for managing the stack.
Performance
Hair count drives viewport and render cost. You can work with a lighter preview count while grooming and raise it for final output, keeping interaction fast. See Hair and Guide Viewport Display.