Children

Children are Hair and Keyed particles assigned subparticles. They make it possible to work primarily with a relatively low amount of Parent particles, for whom the physics are calculated. The children are then aligned to their parents. Without recalculating the physics the number and visualization of the children can be changed.

Children can be emitted from particles or from faces (with some different options). Emission from Faces has some advantages, especially the distribution is more even on each face (which makes it better suitable for fur and the like). However, children from particles follow their parents better, e.g. if you have a softbody animation and do not want the hair to penetrate the emitting mesh. But see also our manual page about Hair.

If you turn on children the parents are no longer rendered (which makes sense because the shape of the children may be quite different from that of their parents). If you want to see the parents additionally turn on the Parents button in the Visualization panel.

Children carry the same material as their parents and are colored according to the exact place from where they are emitted (so all children may have different color or other attributes).

The possible options depend from the type of particle system, and if you work with Children from faces or Children from particles. We do not show every possible combination, only the settings for a Hair particle system.

Settings

Child Type

None

No Children are generated.

Simple

Children are emitted from the parent position.

Size

Only for Emitter. A multiplier for children size.

Random

Random variation to the size of child particles.

Interpolated

Children are emitted between the Parent particles on the faces of a mesh. They interpolate between adjacent parents. This is especially useful for fur, because you can achieve an even distribution. Some of the children can become virtual parents, which are influencing other particles nearby.

Seed

Offset the random number table for child particles, to get a different result.

Virtual

Relative amount of virtual parents.

Long Hair

Calculate children that suit long hair well.

Common Options

Display

The number of children in the 3D View.

Render

The number of children to be rendered.

Effects

From left to right: Round: 0.0, Round: 1.0, Clump: 1.0, Clump: -1.0, Shape: -0.99.

Use Clump Curve

Use Curve Widget instead of parameters.

Clump

Clumping amount along child strands. The children may meet at their tip (1.0) or start together at their root (-1.0).

Shape

Form of Clump. Either inverse parabolic (0.99) or exponentially (-0.99).

Use Clump Noise

Todo.

Length

Length of child paths.

Threshold

Amount of particles left untouched by child path length.

Radius

The radius in which the children are distributed around their parents. This is 3D, so children may be emitted higher or lower than their parents.

Roundness

The roundness of the children around their parents. Either in a sphere (1.0) or in-plane (0.0).

Seed

Offset in the random number table for child particles, to get a different randomized result.

Roughness

Use Roughness Curve

Use Curve Widget instead of parameters.

Uniform, Size

It is based on children location so it varies the paths in a similar way when the children are near.

Endpoint, Shape

“Rough End” randomizes path ends (a bit like random negative clumping). Shape may be varied from <1 (parabolic) to 10.0 (hyperbolic).

Random, Size, Threshold

It is based on a random vector so it is not the same for nearby children. The threshold can be specified to apply this to only a part of children. This is useful for creating a few stray children that will not do what others do.

Kink

Child particles with Kink.

From left to right: Curl, Radial, Wave, Braid, Spiral.

With Kink you can rotate the children around the parent. See Fig. Child particles with Kink. above picture for the different types of Kink.

Kink

Nothing

Deactivated.

Curl

Children grow in a spiral around the parent hairs.

Radial

Children form around the parent a wave shape that passes through the parent hair.

Wave

Children form a wave, all in the same direction.

Braid

Children braid themselves around the parent hair.

Spiral

Generates a spiral at the end of each hair.

Radius, Resolution

Define the overall size.

Shape

Makes a the spiral grow in- or outward.

Note

Alignment Limitations

When hair is pointing straight up (along the chosen spiral axis, default Z), spirals may not show up! This is a limitation of the projection method used. Giving a slight tilt or random orientation to hairs fixes this.

Common Options

Amplitude

The amplitude of the offset.

Clump

How much clump effects kink amplitude.

Flatness

How flat the hairs are.

Frequency

The frequency of the offset (1/total length). The higher the frequency the more rotations are done.

Shape

Where the rotation starts (offset of rotation).