Houdini 20.0 Nodes Geometry nodes

Feather Clump geometry node

Clumps/Splits the barbs of a feather.

The Feather Clump operator performs the clumping and splitting of the barbs of a feather. Barbs hold on to oneanother thanks to hooks (barbules) on each barb. In reality, splits in the barb structure form wherever the hooks have been torn apart with sufficient force. This operator intends to mimic this effect with relatively simple means, while providing plenty of artistic control.

Parameters

Group

This parameter specifies the group of feathers to work on.

Splits

Split Location Mode

Controls where barbs split along the shaft of the feather.

Parametric

Create barb splits based on the parameters below.

From Attribute

Use a point attribute to define split locations. Any non-zero value will create a split at that point.

Split Attribute

Frequency

The frequency at which splits occur along the feather.

Jitter

Adds jitter/randomness on top of the locations defined by frequency.

Seed

The random seed used for offsetting split locations when using the Jitter parameter.

Create Split Attribute

Creates an attribute where points that have a split are set to 1.

Split Attribute

The name of the split attribute to output.

Create Clump Id Attribute

Creates a clump id attribute where each clump formed by splits is assigned an id. This will be an int tuple with two values, one for each side of the feather.

Clump Id Attribute

The name of the Clump Id attribute to output.

Do Clumping

Enables controls for pulling barbs within each clump closer together. This is optional because you may want to output barb clump ids from this operator, then use other operators to do the actual barb manipulation.

Clumping

Amount

The amount of clumping or splitting applied to the barbs. Increasing the value will lead to stronger clumping or splitting, while decreasing it will result in weaker effects.

Falloff

The falloff of the split along the length of the barb, effectively changing the shape of the void formed in the barb surface.

Split Depth

The depth of the split measured from the outline of the feather. A value of 1.0 splits barbs all the way down to their roots.

Shift

The amount of horizontal shift applied to the barbs during the clumping or splitting process. A value of 0.5 causes no shift, while higher values shift barbs towards the tip of the feather and lower values shift them towards the root.

Skin UV Attribute

The name of the skin UV attribute. This is used when overriding parameters with textures or texture primitives.

Feather UV Attribute

The name of the feather UV attribute set (usually uv, uv_barbl, uv_barbr). This is used when overriding parameters with textures or texture primitives.

Inputs

Input 1

Groom Curves

Input 2

Skin Geometry

Input 3

Skin VDB and Texture Primitives

Outputs

Output 1

Groom Curves

Output 2

Skin Geometry

Output 3

Skin VDB and Texture Primitives

Geometry nodes