# ZBrush — Sculpting for MetaHuman What to do in ZBrush so a sculpted historical likeness becomes a clean, animatable MetaHuman. ZBrush is used at **two different moments**, with opposite rules: | Moment | Input | Rule | |---|---|---| | **A. Likeness sculpt** (before MetaHuman) | Any mesh you like | Free topology, but follow the MetaHuman input rules below so the solve succeeds | | **B. Refining a MetaHuman** (after DCC Export) | The MetaHuman head exported from Unreal | **Never change topology or vertex order.** Sculpt on layers, return the same mesh to Maya's Expression Editor | ## A. Likeness sculpt for Mesh to MetaHuman / From Custom Mesh ### Geometry - **Scale and units.** Work to real-world size: an adult head is about 22–24 cm crown to chin. Set export scale so the mesh arrives in centimetres and check it in Maya or Unreal before solving. - **Orientation.** Face looking straight forward along the front axis, no tilt or turn. Mesh to MetaHuman fails on badly oriented meshes. - **Clean surface.** No holes, non-manifold edges, stray vertices or self-intersections. DynaMesh freely while sculpting, then ZRemesher or Decimation Master for export. - **Vertex count.** Mesh to MetaHuman recommends **OBJ** for meshes over about 200,000 vertices (large FBX files cause problems). A decimated mesh with polypaint is usually enough; fine detail goes in maps, not in the fitting mesh. - **Combine on import.** Keep the head and eyes as separate subtools in ZBrush, but import with *Combine Meshes* in Unreal. ### Face (neutral pose) The neutral is the foundation of every expression: MetaHuman stores expressions as differences from it. - **Relaxed and symmetrical.** Keep asymmetry only where the photographs show a permanent feature, and record it in the likeness log. - **Eyes open, sclera visible.** The whites of the eyes must show, with clear separation between eyeball and eyelid. Model eyeballs as a separate subtool with white sclera. Closed or empty sockets break tracking. - **Lips sealed.** Completely closed, with no gap and no intersection. Teeth, if modelled, sit behind the lips without poking through. - **Eyelids** must not intersect the eyeballs or each other. - **Ears and nostrils** clearly formed; extra camera frames of them help the solve. - **No hair volume.** Sculpt the skull and hairline, not the hairstyle. Hair, beards and brows become grooms later. A hair mass on the forehead or cranium will be fitted as skull. - **Brows and lashes** only as faint polypaint, never as geometry. ### Texture / polypaint - Provide a **flat, unlit albedo** (polypaint exported as a texture). Mesh to MetaHuman tracks better on an albedo-textured mesh. - If there is no texture, use flat, front-facing, symmetrical lighting in the Identity viewport, and keep sclera clearly lighter than skin. - Keep ambient occlusion, cavity and specular **out of** the albedo. - Pores and wrinkles belong in **normal or displacement maps** baked from the high-resolution sculpt. MetaHuman 5.8's unbaked-texture controls let you bring custom maps in later. ### Body (From Custom Mesh, MetaHuman 5.8) - **A-pose** close to the MetaHuman A-pose: arms down about 45°, palms down or in, fingers separated, feet flat and slightly apart. - **Nude or tight-fitting.** Loose clothing (skirts, robes, coats) makes the solver fit the garment silhouette, not the body. Sculpt the body under the costume and dress it later in Marvelous Designer. - **Realistic proportions.** The solver is built from real human morphology; extreme proportions solve poorly and pinch in animation. - **Period body.** Consider period posture and build (corsetry changes the torso silhouette, but sculpt the body and let the costume shape it). ### Export checklist - [ ] Real-world scale in cm, verified in Unreal - [ ] Facing front, no tilt - [ ] Eyes open, sclera white, eyelids clean - [ ] Lips sealed, no intersections - [ ] No hair geometry - [ ] Clean, watertight, no stray vertices - [ ] OBJ if over about 200k vertices - [ ] Flat albedo exported; detail maps baked separately - [ ] Body in A-pose, unclothed or tight-fitting - [ ] Likeness log updated ## B. Refining a MetaHuman in ZBrush (without breaking the rig) After Mesh to MetaHuman and MetaHuman Creator, the character is exported with **DCC Export** and assembled in Maya ([[MetaHuman for Maya — Considerations]]). ZBrush is then used to push likeness further on the MetaHuman head itself. - **Import the exported head, sculpt, return the same mesh.** No DynaMesh, ZRemesher, Decimation, Close Holes or anything that adds or removes points. - **Preserve vertex order.** Use GoZ or OBJ/FBX round trips that keep order; test by re-importing onto the original in Maya as a blend shape. - **Use layers.** One layer for the neutral correction; one layer per expression if sculpting expressions for the Expression Editor. - **Respect vertex semantics.** An eyelid-edge vertex must stay on the eyelid edge; do not slide vertices across the lip line or eye corners. Move volume, not landmarks. - **Minimize the delta.** Large moves far from the joints make expressions carry mass oddly; bigger shape changes belong back in Mesh to MetaHuman or Creator. - **Detail stays in maps.** Bake new normal maps from a subdivided copy; send the level-1 mesh back. ## Historical-likeness notes Full research and rules: [[ZBrush — Likeness and Age Research]]. - Early daguerreotypes are often **mirror-reversed**; check hair parts and asymmetries against other images. - Sitters held still for long exposures; faces read as stern. The neutral should be relaxed, not the photograph's set expression. - Match the **dated self**: the 1847 comet night needs Mitchell at 29, not the famous late-life portraits. - Where evidence is thin (Absalom Boston), sculpt a documented *type* and say so on the label. **Owner:** character artist. Tutorials: [[ZBrush — Tutorials]] · local: [[Tutorial — Starting a Head and Base Body in ZBrush]] (part A) · [[Tutorial — ZBrush No-Topology-Change Round Trip]] (part B) · textures: [[Tutorial — Flat Albedo from Polypaint]] · [[Tutorial — Baking Detail Maps for MetaHuman]] Sources: [[Sources — 2026-09-19]]