New Curves Hair system was implemented in Blender 3.3.

I have converted my old Particle System hair to Curves hair, using the method described in this Youtube video. However, my issue is that the hair doesnt follow my character when i dial in shapekeys for the character.

The steps i took were as follows:

  1. Converted Particle System Hair to Curves (using special menu in Particle Systems Properties menu)
  2. Under Curves properties, I have updated the Surface to be my scalp mesh, and the UV Map to my scalp mesh UV Map
  3. In Sculpt Mode, I have clicked 'Snap to nearest surface'
  4. I then dialled in a shapekey on my character (which has the scalp connected via a surface deform modifier), and the scalp moved but the hair stayed where it was.

enter image description here

  • $\begingroup$ Is this a true Surface Deform modifier -or- is it a Geometry Nodes modifier, named Surface Deform, with a single Deform Curves on Surface node in it? The last one is the correct one. It must be on the HairHead object (curves). And the HairHead object should be a child of the surface object (Scalp_HairHead2). $\endgroup$
    – Blunder
    Oct 4, 2022 at 13:02

1 Answer 1


Have a look at your screenshot. The HairHead curves object in the outliner has no modifier. There is no blue wrench icon. But the Scalp_HairHead2 object has one. This looks wrong.

The curves object HairHead must have a Geometry Nodes modifier with a single Deform Curves on Surface node in it.

Furthermore, the HairHead object should be a child of the surface object Scalp_HairHead2.

gn modifier

If you add a Curve > Empty Hair object to a selected object (Shift+A) then Blender ...

  • creates a Curves object
  • makes it a child of the select object
  • enters the values for Surface > Surface and Surface > UV Map in the Object Data Properties panel
  • adds a Geometry Nodes modifier to the Curves object. It's needed when the mesh is deformed by an Armature modifier or shape keys. Note: It's named Surface Deform but it's a Geometry Nodes modifier. Don't confuse it with the true Surface Deform modifier.

If you convert a Hair Particle System to the new Hair Curves you need to do steps 2 to 4 manually.

curves settings

Shape key test: example animation

  • 1
    $\begingroup$ Thank you, that worked perfectly. The only additional thing I needed to do was ensure that the 'Add Rest Position' box was ticked under Object Data Properties on my scalp mesh. $\endgroup$
    – fema camps
    Oct 4, 2022 at 22:13

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