Hair curves to Hair cards converter | Blender Geometry nodes (3.6+)

Here are some little nodes to convert a groom made with the new Blender Hair system into alpha cards to make low-poly hair, fur, feathers, etc... for games or animation.

It snaps premade alpha cards to proxy cards made from the hair curves, allowing you to unwrap your card and use texture atlases. The downside is that the premade cards must have the same shape, point count, and indexes as the proxies.

Here's a tuto explaining the process :

In the blend. file, you'll get 5 geonode groups :

1 - Create Card Instances : Creates a plane out of a Curve Line. Choose a point count and a profile shape. The chosen point matters for the snapping. To be converted to a mesh, unwrapped and given a material manually.

2 - Create Tube Instances : Same as the "Create Card Instances", but to make tubes instead. Point count and Resolution both matter here.

3 - Curves to Cards : Turns your groom into planes to be used as proxies, instances the collection containing your premade hair cards, and snaps them to the proxies. Point count of the original hair curves must be the same as the point count you chose when making the instances.

4 - Curves to Tubes : Same as "Curves to Cards" but for tubes.

5 - Vertex group to Attribute : Useful to create masks out of vertex groups in the shader. Used to paint variation and patterns in the groom.

You'll also find a hair card stylized material, and 3 basic textures atlases (2 for hair, one for hand-painted feathers)

It's best to convert your groom to a mesh once you're done, so you can rig it and export it.

Hope you'll find it useful !