Formats (USDA / USDC / USDZ)

This repo implements parsers/utilities for the formats below.

USDA (.usda) — text

• Human-readable, diff-friendly.
• Often used for “interface” or “edit” layers.

OpenUSD references:

• OpenUSD spec overview: https://openusd.org/release/spec.html
• Formats FAQ: https://openusd.org/release/usdfaq.html

USDC (.usdc) — binary “crate”

• Compact, optimized for load time and random access.
• .usd files may be either text or crate; crate files start with the magic header PXR-USDC.

OpenUSD references:

• Formats FAQ: https://openusd.org/release/usdfaq.html

Implementation notes:

• Crate decoding parity notes live at src/usdc/PIXAR_PARITY.md.

USDZ (.usdz) — package

USDZ is a read-only, uncompressed ZIP container with constraints intended to enable efficient access.

OpenUSD reference:

• USDZ specification: https://openusd.org/release/spec_usdz.html

Key constraints (high level):

• entries are stored (no compression), not encrypted
• entry data must be aligned (commonly 64-byte alignment)