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Hair and Fur Grooming in H17 | SideFX | Character FX & Crowds Production Talks
SideFX TD presents H17 grooming toolset with worked hair examples, covering guide-curve challenges, detailing techniques, and rendering workflows at the London Character FX workshop.
Abstract
A SideFX developer presents the Houdini 17 fur and grooming toolset, focusing first on performance: rewriting the most-used operators (hair generate, hair clump, guide mask, parts of guide process) from VEX-based HDAs into single C++ core operators, giving roughly 4x faster cooks and up to 10x in interactive sessions. He explains attribute data IDs as the caching mechanism that lets hair generate reuse topology and neighbor lookups when only point positions change, stressing the importance of keeping the rest attribute static and avoiding older operators that bump all IDs. The grooming portion demonstrates non-obvious workflows: building eyelashes by snapping a curve to the mesh with the curve SOP and growing hair from it, creating long-hair ponytails with hair generate and a tightness attribute for taper, using clump IDs as cluster attributes in Vellum glue constraints to keep nearby clumps separate, attaching rigid spheres to hair via guide deform and extract transform, and shaping mushroom-like clumps with hair clump attribute copying plus guide process bend.
How to read this
- Category
- Production talk / tool walkthrough (H17 grooming toolset)
- Contributions
- Presents performance gains from rewriting key grooming operators from VEX HDAs into C++ core operators (roughly 4x faster cooks, up to 10x interactive)
- Explains attribute data IDs as the caching mechanism that lets hair generate reuse topology and neighbor lookups when only point positions change
- Demonstrates non-obvious grooming workflows: snapped-curve eyelashes, taper via a tightness attribute, clump IDs as Vellum glue cluster attributes, attaching rigid spheres via guide deform, and mushroom clumps with hair clump attribute copy plus guide process bend
- Context
- A vendor walkthrough of the Houdini 17 fur/grooming system, situated in the procedural guide-curve grooming paradigm and the introduction of Vellum constraints.
- Correctness
- Vendor practice, not peer-reviewed; the speedups are reported by the developer and the caching benefits depend on keeping rest attributes static and avoiding older operators that bump all IDs, which is a real usage caveat to heed.
- Clarity
- Accessible to grooming artists; a single viewing conveys both the performance story and the recipes.
- How to read it
- Watch once for the data-ID caching mental model (it explains why grooms recook fast), then return to specific recipe segments as reference when building eyelashes, ponytails or clumps.
Related work
Keywords
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