Hair Attachment Info

The Hair Attachment Info node provides information about how and where hair curves are attached to a surface mesh. It allows nodes to retrieve stored attachment coordinates, verify whether the attachment is still valid, and access the surface normal at the attachment point. This information is essential for deformation, simulation, and reattachment of hair when the surface mesh changes.

Inputs

Surface Geometry

The surface geometry to which the hair curves are attached. This is typically the same mesh used during hair generation or interpolation.

Surface UV Map

The UV map on the surface mesh used to locate the curve attachment points. It allows retrieving the stored attachment coordinates for each curve.

Outputs

Attachment UV

The UV coordinates on the surface where each curve is attached. These are typically stored per curve and used to find the correct attachment location even if the surface topology changes.

Attachment is Valid

A boolean output indicating whether each curve has a valid stored attachment. This can be used to detect invalid or missing attachment data after topology edits or surface replacement.

Surface Normal

The normal direction of the surface mesh evaluated at the curve’s attachment point. This can be used for aligning hair roots, orienting instances, or driving deformation based on surface orientation.