How does the USD BasisCurves schema at v26.08 describe hair-style curves, and what does Blender 5.2.2 write when it exports particle hair and Curves objects to USD?
Blender v5.2.2 writes particle hair to USD as BasisCurves (cubic bspline, or cubic catmullRom with pinned wrap) with points, curve vertex counts and a display colour, and no widths. The USD schema description of BasisCurves for hair, the Curves-object writer (widths from radius, UV primvars, velocities) and the parents-only manual note remain producer-verified.
Blender v5.2.2 writes particle hair to USD as BasisCurves (cubic bspline, or cubic catmullRom with pinned wrap) with points, curve vertex counts and a display colour, and no widths. The USD schema description of BasisCurves for hair, the Curves-object writer (widths from radius, UV primvars, velocities) and the parents-only manual note remain producer-verified.
Curator qualifications: Code/docs read 2026-10-22; no hair exported. schema.usda, usd_writer_curves.cc and USD manual page not re-read.
Limitations: Code/docs read 2026-10-22; no hair exported.
Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.
Structured fields
{
"citations": [
{
"url": "https://github.com/PixarAnimationStudios/OpenUSD/blob/ee47c679abde5b467a7b6a41f3b2285564a4222e/pxr/usd/usdGeom/schema.usda",
"note": "source/blender/io/usd/intern/usd_writer_hair.cc at d13f752 L34-80"
},
{
"url": "https://github.com/blender/blender/blob/d13f752e3b9c4f8c261cda552b1021f8bcc0382c/source/blender/io/usd/intern/usd_writer_hair.cc",
"note": "source/blender/io/usd/intern/usd_writer_hair.cc at d13f752 L34-80"
},
{
"url": "https://github.com/blender/blender/blob/d13f752e3b9c4f8c261cda552b1021f8bcc0382c/source/blender/io/usd/intern/usd_writer_curves.cc",
"note": "source/blender/io/usd/intern/usd_writer_hair.cc at d13f752 L34-80"
},
{
"url": "https://docs.blender.org/manual/en/latest/files/import_export/usd.html",
"note": "source/blender/io/usd/intern/usd_writer_hair.cc at d13f752 L34-80"
}
]
}Evidence claims
- [sourced_fact] Blender v5.2.2 writes particle hair to USD as BasisCurves (cubic bspline, or cubic catmullRom with pinned wrap) with points, curve vertex counts and a display colour, and no widths. The USD schema description of BasisCurves for hair, the Curves-object writer (widths from radius, UV primvars, velocities) and the parents-only manual note remain producer-verified. · locator: source/blender/io/usd/intern/usd_writer_hair.cc at d13f752 L34-80 source
Rights
| component | license | hosting | redistribution | modification | training | Evidence and notes |
|---|---|---|---|---|---|---|
| documentation | unknown | permitted | permitted | unknown | unknown | Applies to this original summary only, not to the cited sources. |
Linked records
- cites → https://docs.blender.org/manual/en/latest/files/import_export/usd.html
- cites → https://github.com/PixarAnimationStudios/OpenUSD/blob/ee47c679abde5b467a7b6a41f3b2285564a4222e/pxr/usd/usdGeom/schema.usda
- cites → https://github.com/blender/blender/blob/d13f752e3b9c4f8c261cda552b1021f8bcc0382c/source/blender/io/usd/intern/usd_writer_curves.cc
- cites → https://github.com/blender/blender/blob/d13f752e3b9c4f8c261cda552b1021f8bcc0382c/source/blender/io/usd/intern/usd_writer_hair.cc