Since 16.0

Parameters

Proxy Display

Shows a rough representation of the hair shapes for faster update.

Skin Voxel Size

Defines the voxel sized used for the scalp VDB. This is used to avoid intersections with the skin.

Type

Controls whether to create polygon or NURBS curves.

Segments Per Guide

Resample all curves to this many segments.

Growth Field Quality

Quality of the field that hair is advected through. The minimum required voxel size is computed internally, based on the radius of your strokes. Doubling the quality value will half this voxel size.

Export Groom Field

Export the VDB volume along with the guide curves.

Drawing

Operation

Draw Guides & Groom

Creates hairs and modifies the groom field.

Groom Only

Modify the groom field without creating hairs.

Radius

Controls the brush radius.

Draw On

Skin

Draw onto the skin.

Screen Plane From Root

Draw hairs in the screen plane, starting at a point on the skin.

Surface Normal From Root

Draw hairs perpendicular to the skin, starting at a point on the skin.

Screen Plane

Draw hairs in the screen plane. This is mostly useful with the Groom Only option.

Create Roots Along Stroke

With this turned on, hairs will be created from any point on the skin that you draw over, as opposed to just where you first click.

Limit Curve Length

Limit the length of curves to the specific value below. In combination with setting Operation to Groom Only, this lets you quickly small areas of short hair. This is useful, for tasks such as drawing eyebrows.

Root Creation

Skin Group

The group of skin primitives to draw hair on.

Display Roots Points Only

Only show the created roots, not the hair curves created from them.

Guide Spacing

The average spacing between guide roots.

Density Scale

Defines density relative to guide spacing.

Density

Force Total Count

Ignore guide spacing and density and just scatter this many roots.

Density Attribute

If this attribute is found on the skin geometry, it used to scale the guide density.

Emergency Limit

Never generate more than this many guides.

Relax Iterations

Perform this many iterations of relaxation. Increasing this value produced more evenly spaced guides, but can slow down interactive drawing performance.

Percentage Of Guide to Use as Root

Scatter roots along this percentage of the drawn curve’s length.

Guide Advection

Shaping

Radius Scale

The radius of all drawn curves is scaled by this value. This is a global change and will affect all strokes.

Skin Normal Force

The strength of the force pushing hairs out of the skin geometry.

Blend Width

Width of the region around the skin that the Skin Normal Force affects.

Inner Blend Width

Width of the region inside the skin that the Skin Normal Force affects.

Ramp Effect

Controls how much of an effect the Guide Shape ramp has. The closer this is to zero, the more hairs will grow straight and ignore the ramp shape.

Guide Shape

Controls the shape of hair grown around each stroke from root to tip.

Advection

Advection Type

The integration method to use for advection. The lower options are generally more accurate as well as expensive.

Length

Scale the length of all curves by this value.

Increasing the length will only work up to the point you drew your strokes, so values far above one usually don’t work.

Samples

The number of substeps to perform during advection.

This controls the accuracy of advection, but not the final segment count. To do so, use Segments Per Guide.

Note

If you are interested in the technical background of hair advection techniques, please refer to the original 2013 Siggraph talk Hair growth by means of sparse volumetric modeling and advection by Ashraf Ghoniem and Ken Museth, DreamWorks Animation.

See also

Geometry nodes