Smooth Surface Operator
The Smooth Surface operator subdivides the base surface and re-projects hair roots onto the smoother result. It exists to solve a specific problem: Ornatrix hair is topology dependent, so if a mesh is subdivided - for example at render time - its shape changes and the hair roots no longer match the surface they were grown on. Smooth Surface keeps the roots aligned to the subdivided surface so the groom stays correct.
How it works
The operator uses the OpenSubdiv algorithm to compute the subdivided geometry, then recalculates each root's position on the new, smoother surface. The hair then sits on the subdivided mesh exactly as intended.
Where to place it
Add Smooth Surface at the top of the operator stack, above all styling. This ensures the roots are re-projected after effects such as clumping, frizz, and curl have been computed, so subdivision does not disturb your styling.
Related
- Guides from Mesh Operator - root generation, which is topology dependent.
- The Operator Stack - why operator order matters.