Tutorial — XGen Period Hair for MetaHuman

Augmented Traveler local tutorial. Back to Grooms — Tutorials · evidence first: Tutorial — Period Hairstyles from Evidence · Maya setup: MetaHuman for Maya — Considerations · after this: Tutorial — Hair Cards and Groom LODs for Headsets

How to build a period women's hairstyle in Maya XGen with Epic's Groom Starter Kit, export it with the Groom Exporter, and bring it into Unreal as a bound Groom Asset and a Wardrobe Item for MetaHuman Creator. The worked example is Maria Mitchell, 1847: centre part, smooth bands over the ears, low bun.

Draft. Written from Epic's Groom Starter Kit, Groom Exporter and UE 5.8 hair docs, and Autodesk's XGen help. Correction to our earlier plan: the Starter Kit uses a legacy XGen Description (collection head, description buzzcut), not an XGen Interactive Groom. The Groom Exporter documents support for XGen Descriptions only. Correct menu names here after the first run.

1. What you need

Item Detail
Maya The Starter Kit page states Maya 2023–2026. Maya 2027 is not listed: unconfirmed; check on first use
Plugin MetaHuman for Maya (provides the Groom Exporter under the MetaHuman menu)
Kit Maya_Groom_Template project; scene MH_Groom_Template with the MH Groom Head and region grooming meshes
Unreal UE 5.8 with the Groom and Alembic Groom Importer plugins; Support Compute Skin Cache on (Project Settings → Rendering → Optimization)
Evidence A signed hair evidence sheet (Tutorial — Period Hairstyles from Evidence)

2. Plan the groups

Unreal supports up to 15 groom_group_id values per groom asset. Split the style so each part can have its own density, width and card settings.

Group Description name Notes for 1847
0 front_bands From the parting, down over the ears, then back
1 crown Smooth, flat, close to the scalp
2 back_nape Swept up to the bun
3 bun A coil at the back, low on the head
4 flyaways Very few; period hair was not blow-dried but was dressed smooth

Keep the bun as its own description. It is the part most likely to be hidden by a cap (Tutorial — Hair Under Caps and Bonnets).

3. Build it in XGen

  1. Open the kit. Set the project to Maya_Groom_Template and open MH_Groom_Template. Study the buzzcut description: guides, interpolated hair, Noise and Cut modifiers, a density map and a Width Ramp.
  2. Duplicate the setup per group. Create one description per group in section 2 on the head (or a region grooming mesh). Keep the kit's settings as the starting point.
  3. Paint density.
    • Paint a density map per description. Leave a clean, narrow parting line at zero density for front_bands and crown.
    • Keep the hairline soft; paint lower density at the temples.
  4. Place guides.
    • Start with few guides (tens, not hundreds) along the parting, over the ears and at the nape.
    • Shape front_bands so the hair runs down from the parting, covers the top of the ear, then turns back to the nape. This loop is the 1840s signature.
    • For the bun, draw guides that spiral around a small sphere placed at the back of the head (a proxy you delete later).
  5. Add modifiers from the XGen Editor Modifiers tab ("Add new modifier" icon).
    • Clumping: light. Period hair was smoothed with oil and brushing. Use Flatness to keep bands flat; keep Curl at zero.
    • Noise: very low on bands and crown; slightly more on flyaways.
    • Cut: trims ends to vary length inside the bun.
    • Collision exists as an XGen modifier; use it against a cap proxy if the figure wears one.
  6. Width. Use the Width Ramp: slightly thinner at the tip. The Groom Exporter exports groom_width when width data is present.
  7. Check against the evidence. Match the front view in the camera of the orientation-checked portrait. Flat on top, ears covered as the sheet says.

Interactive grooming (optional). Maya's XGen Interactive Groom (Generate → Create Interactive Groom Splines) has comb, grab, smooth, part and clump tools and can export an Alembic cache. The Groom Exporter does not document it, and the attributes Unreal needs may be missing. Use it only for blocking unless tested.

4. Export with the Groom Exporter

  1. Open MetaHuman → Groom Exporter.
  2. Set the Project Directory (workspace.mel), Scene File and the Model Mesh (the head).
  3. Scene Up Axis: Y (default for Unreal).
  4. Select all guides. They are tagged groom_guides.
  5. Assign a groom_group_id to each interpolated description (0–4 from section 2).
  6. Export the Alembic. Expected attributes: groom_width, groom_rootuv, groom_group_id, groom_id, groom_guides.
  7. Name it GR_Mitchell_1847_Hair.abc.

A non-compliant Alembic imports but without the custom attributes. If widths look uniform in Unreal, check the export.

5. Into Unreal

  1. Import the .abc. In Groom Import Options, check rotation and guide settings, then Import. Result: a Groom Asset.
  2. Material. Assign the kit's MI_Hair material instance. Set colour from the evidence sheet in the MetaHuman hair overrides (Melanin, Redness, Roughness).
  3. Binding. Right-click the Groom Asset → Create Binding. The kit's source mesh is SKM_MH_Groom_Head; set the target to Mitchell's head mesh. Save as GB_Mitchell_1847_Hair.
  4. Test. Add a Groom component to the head, assign the groom and binding. Play a head turn and a nod from the monologue take.
  5. Physics (kiosk only). Groom Asset Editor → Physics → Enable Simulation. Keep stiffness high for oiled, pinned hair. The bun should barely move.
  6. LODs and cards for headsets: Tutorial — Hair Cards and Groom LODs for Headsets.

6. Wardrobe Item and Creator

  1. Create a MetaHuman Wardrobe Item that references the Groom Binding. It supports a secondary colour and material overrides.
  2. In MetaHuman Creator, add it to Mitchell's head hair slot. Creator's groom slots are head hair, eyebrows, eyelashes, mustache, beard and peach fuzz.
  3. Adjust overrides (Melanin, Redness, Whiteness) to the evidence sheet values.
  4. To share between projects, package as a MetaHuman Package (.mhpkg).

7. Practice exercise

Build a 1860s variant for an older Nantucket woman: centre part, smooth back into a chignon, hair net around it. Make the net a separate mesh (costume), not hair. Compare poly and strand counts with the 1847 groom.

8. Check before historian review

Sources