Gantry and Preflight
Gantry and Preflight are peers in the Reality Check family — a growing family of professional tools for OpenUSD on Apple platforms. They share an engine. They have different jobs. They are designed to work together.
Raw model → Gantry (convert) → Preflight (validate) → ShipThe difference
Section titled “The difference”| Gantry | Preflight | |
|---|---|---|
| Role | Authoring · Convert | Quality gate · Validate |
| Job | Convert 3D to USDZ | Validate and repair OpenUSD |
| RealityKit compatibility check | No | Yes |
| Automated fix workflows | No | Yes (Pro) |
| Material editing | Yes | Yes |
| Format conversion | Yes | Yes (included in Preflight) |
Preflight includes everything Gantry can do, plus validation, diagnosis, and repair. Gantry exists for users who only need conversion. Same engine, smaller package — like Compressor to Final Cut Pro.
When to use Gantry
Section titled “When to use Gantry”Use Gantry when:
- You have a FBX, glTF, OBJ, or STL file and need USDZ
- You want to preview how a model looks in RealityKit before using it
- You need to tweak materials or optimize textures before exporting
- You don’t need USD validation or automated repair
When to use Preflight
Section titled “When to use Preflight”Use Preflight when:
- Your USDZ looks wrong in AR Quick Look or visionOS and you don’t know why
- You want to run RealityKit compatibility checks before submitting to the App Store
- You have a complex USD scene with references, layers, or compositions
- You need automated fixes applied to structural issues
The handoff
Section titled “The handoff”Gantry can open Preflight directly. If a converted model has structural issues that Gantry can’t address — missing default prim, broken references, scale or axis problems — Preflight is the next step. Validation in Preflight is free. Fixes require Preflight Pro.