Houdini 20.5 Nodes Geometry nodes

Feather Deform geometry node

Deforms feathers by using other feathers or polygon surfaces.

Parameters

Group

Select the group of feathers to deform. This allows you to choose specific feathers or sets of feathers within the system for targeted deformation.

Deformer Type

Determine the type of deformer to use for the deformation process. Three options are available:

Curves

Use other curves as deformers.

Feathers

Use other feathers as deformers. Usually used to deform high resolution (high barb count) feathers with lower resolution feathers.

Surfaces

Use polygon surfaces as deformers. Usually used with polygon surfaces generated with the Feather Surface SOP.

Mode

Determine the mode of operation for the Feather Deform operator.

There are two steps to the deformation process: Capture and the deformation itself. The capture step binds each point on a feather to the deformer, storing the binding information in a set of attributes. When doing the actual deformation, this information is used to move & rotate each feather point using the geometry supplied via the deformer input.

This option allows you to split this step across two nodes, one that only does the capture and one that only does the deformation.

Capture and Deform

Capture and deform all in one step.

Capture

Only capture the deformation information from the rest deformer geometry and store it in point attributes.

Deform

Deform the feathers using previously computed capture information stored in point attributes on the input feathers.

Capture

Piece Attribute

Specifies the name an attribute that identifies each feather. The piece attribute identifies the corresponding deformer piece for each feather, as it is assumed that each feather will be affected by a single deformer geometry. This attribute must be present on the feather input and the rest deformer input.

Deform

Treat Deformer as Subdivision Surface

Control whether the deformer geometry should be treated as a subdivision surface. When enabled, the deformer geometry is interpreted as a subdivision surface, resulting in a smoother deformation of the feathers. Usually only disabled where more performance is required or for special cases where the feather should stick exactly to the deformer surface.

Transfer Velocity

Transfers velocity from animated deformers to feathers. This takes into account both linear velocity v and angular velocity w to produce a linear velocity v on the output.

Tip

You can generate velocities on the deformer using a Trail SOP.

Note

Currently only surface deformers are supported.

Deform Barbs

Determine whether the barbs of the feathers should be deformed along with the feather curves. When enabled, the barbs will be affected by the deformation, resulting in a cohesive and realistic deformation of the entire feather structure. With this disabled, only the shaft curve will be deformed along with its barborient rotation values, meaning barbs will still rotate. In some situations this may be sufficient or even desired.

Attributes to Transform

Specify the attributes that should be transformed during the deformation process.

Rigid Transform

Deform each curve rigidly, while matching the deformer as closely as possible. Only applies translation and rotation to the entire feather, preserving the shape of each input feather perfectly.

Delete Capture Attributes

Deletes capture attributes after the deform step is finished.

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 and UV mode on parameters is set to Curve UV (Sample texture only at the shaft’s uv) or Feather UV (Sample texture at each barb point).

Inputs

Input 1

Groom Curves

Input 2

Skin Geometry

Input 3

Skin VDB and Texture Primitives

Input 4

Rest Deformers

Input 5

Animated Deformers

Outputs

Output 1

Groom Curves

Output 2

Skin Geometry

Output 3

Skin VDB and Texture Primitives

Geometry nodes