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USDKit

Reference for USDKit, the system framework (new in the 27 releases) that gives Swift apps first-class support for USD (Universal Scene Description, the industry-standard 3D scene format) — opening and traversing stages, editing prims and attributes, applying schemas, and exporting compressed USDZ packages, with direct RealityKit integration.

When to Use

Use this skill when:

  • Reading, inspecting, or editing a USD/USDZ file in Swift
  • Building 3D content pipelines (authoring, converting, compressing assets)
  • Adding accessibility metadata to 3D assets
  • Exporting USDZ packages with mesh and texture compression
  • Rendering a USD stage directly in RealityKit (USDStageComponent)
  • Deciding between USDKit, SwiftUSD, and embedding OpenUSD

Example Prompts

  • "How do I open and edit a USD file in Swift?"
  • "How do I reference one USD file from another?"
  • "How do I add accessibility labels to a 3D asset?"
  • "How do I shrink my USDZ files for delivery?"
  • "How do I render a USD stage in RealityKit without converting it?"
  • "Should I use USDKit or SwiftUSD?"

What This Skill Provides

USD Concepts

  • Layers, composition, stages, prims, schemas, attributes, metadata

Stage Workflows

  • Opening stages from URLs, file paths, or layers; in-memory stages
  • Traversal (descendants, children, predicates), defining prims, adding references

Editing

  • Typed attribute subscripts, transform operations, API schemas
  • The standardized AccessibilityAPI schema for 3D assets

Export

  • exportPackage with AOM mesh compression and AVIF texture compression
  • Preview and usdcrush no-code equivalents

RealityKit Bridge

  • USDStageComponent and USDPlayer for rendering stages directly

Ecosystem Context

  • OpenUSD/MaterialX/OpenVDB updates, Particle Fields (Gaussian splats in USD), Preview 3D editing, Safari Model tag, SwiftUSD alternative
  • RealityKit – Displaying and interacting with 3D content; use it (not USDKit) to simply show a USDZ model
  • RealityKit API Reference – Component catalog including the 27-cycle additions and Gaussian splat rendering

Released under the MIT License