USD vs FBX

At the very top of the node is an Import dropdown with two choices — USD (the default) and FBX. Both produce the same shaded character with the same lookdev controller, and the rig builds on either; they differ only in import speed, memory use, and a few features that depend on data Character Creator writes to one export but not the other.

TL;DR — what you get from each

	USD (default)	FBX
Import speed	less than a minute, even for HD characters	1 - 3 min (grows with character weight)
Memory (one loaded character)	less than 8GB, even for HD characters	~10–40 GB
RAM to plan for	16 GB min / 32 GB recommended	48 GB min / 64 GB recommended (HD)
Geometry, skeleton, body + facial animation	✅ Full	✅ Full
Materials (skin, eyes, teeth, hair, clothing)	✅ Full	✅ Full
Subsurface, displacement, Skin Fix, render rig	✅ Full	✅ Full
The APEX rig, the facial rig and every animation tool	✅ Full	✅ Full
Real CC eye & skin values (iris color, iris size, limbus, sclera, SSS)	✅ Read from the file & auto-applied	⚠️ Not exported — generic starting defaults
Expression wrinkles	❌ Not in the USD export	✅ Yes
Hair root-to-tip ombré + highlight streaks + flow sheen	❌ Maps not in the USD export	✅ Yes
Hair flat re-dye + Lightness (Bleach)	✅ Yes	✅ Yes

Bottom line

Use USD for almost everything — it's far faster, far lighter, and better at eyes/skin because it carries Character Creator's real shader values. Switch to FBX only when you specifically need animated expression wrinkles or the full hair re-dye (root-to-tip / highlight streaks).

The best-quality workflow

An FBX character. The expression wrinkles are the single feature that makes a Character Creator face read as alive in motion, and they're FBX-only — the rig carries them through to its output, so a face you animate on the rig wrinkles the way Character Creator's does. When the look matters, import the character as FBX.

An honest caveat

This is the best-quality path, not the lightest one. An FBX-imported character is memory-heavy no matter what — that's the cost of carrying the wrinkle data, and it's unavoidable if you want wrinkles. Once the rig is built, Stash Rig (on by default) means a reopened scene never imports the FBX again, so you pay the import once per character, not once per session. See Rig Settings. If you don't need wrinkles at all, a plain USD import is the lighter choice.

Why USD is so much faster and lighter

Character Creator's FBX stores every facial blendshape as a full mesh copy, and Houdini has to expand all of them on import — tens of gigabytes of RAM and a minute or more on a heavy HD character. The USD export keeps those blendshapes sparse, and the tool keeps them sparse through deformation too: only the expressions actually active on the current frame are computed. On the heaviest HD character, working footprint drops from ~26 GB via FBX to under 8 GB via USD, and raw import time drops from a minute and a half to about a second — the gap grows the heavier the character.

What USD does better — real Character Creator eye & skin values

The FBX export leaves out most of Character Creator's HD eye shader, so in FBX mode the eye controls start from generic defaults you dial in by eye. The USD export carries Character Creator's actual shader values, so in USD mode the tool reads them and seeds the controller automatically — real iris color (when CC actually tinted it), iris size and limbal ring, and sclera shading and subsurface amount from the real per-character values. It's all still adjustable; these are just smarter starting points, and Reset to Defaults returns to them. See Eyes.

What USD mode does not carry

Character Creator's USD export omits some data the FBX export includes. Where that happens, the affected controls stay visible but are disabled with an "(FBX import only)" note — nothing is hidden or silently broken.

Expression wrinkles — the animated head-wrinkle system is FBX only; the USD export contains no wrinkle maps or weights. See Wrinkles.
Root-to-tip and highlight hair re-dye — Character Creator's USD export leaves out the hair root, ID, and flow maps, so the ombré recolor, highlight streaks, and flow-based sheen are FBX only. A flat re-dye and the Lightness (Bleach) control still work in USD. See Hair.

Everything else — including displacement, the rig and every animation tool — works in both modes.

Motion clips

The rig's Clip Files list takes Character Creator USD Motions clips and FBX animation alike — a USD Motions clip is the small, fast one. A clip exported on a different character is retargeted automatically, but it is an approximation; see Clips & Layers.

Switching modes

The Import dropdown swaps which file field is shown — USD File or FBX File — and builds accordingly on Build Character. Before a rig exists you can switch any time; just set the matching file. Once the rig is built it is frozen to the character it was built from, so switching modes afterwards changes nothing until you delete the rig node and press Build Character again.

Next: Preparing Your Character covers how to export for both modes.