Export & Texture Optimization

Preflight separates exporting from texture optimization so the common case stays fast while power users retain full control.

Exporting a Scene

File > Export… (Cmd+E) opens a standard save panel. Pick a destination, hit Save. The export uses your current texture optimization settings (or sensible defaults if you haven’t changed them).

Preflight supports two export modes:

Mode	Description
Export (Fixed)	Preserves the scene graph structure — references, payloads, sublayers, and variants are kept intact. Produces a .usdz archive.
Export (Flattened)	Collapses the full composition into a single layer. Useful for delivery to renderers or platforms that don’t support layered USD.

Both modes apply your texture optimization settings during export.

Optimize Textures

File > Optimize Textures… opens a dedicated panel where you configure how textures are processed during export. Settings are saved across sessions — you set them once and every future export uses them.

Output Format

Controls the texture container format written into the exported archive.

Option	Description
Automatic	Selects the best format for your current workflow. Resolves to PNG for OpenUSD targets and AVIF for RealityKit targets.
PNG	Lossless. Universally supported. Larger file size.
JPEG	Lossy. Good compression for photographic textures. No alpha channel.
AVIF	Modern lossy/lossless codec. Excellent compression with high quality. Supported by RealityKit on macOS 13+ and visionOS.
KTX2	GPU-compressed container (ASTC/BC payloads). Used as a Metal pipeline intermediate. Not a scene-referenced format for Apple runtimes — use only if your pipeline explicitly requires it.

Compression Quality

Controls the compression effort when converting textures.

Option	Description
Automatic	Uses the target workflow default (Fast for quick iterations, Best for final delivery).
Fast	Minimal compression time. Good for iteration.
Balanced	Moderate compression with good quality.
Best	Maximum quality. Slower compression. Recommended for final export.

Max Texture Size

Limits the largest dimension (width or height) of exported textures. Textures exceeding this size are downscaled proportionally.

Option	When to use
Automatic	Uses the target default (4096 px for RealityKit, unlimited for OpenUSD).
1024–8192	Override for specific size budgets.

Generate Mipmaps

Controls whether mipmaps are generated for exported textures.

• Automatic: On for RealityKit, off for OpenUSD.
• On / Off: Explicit override.

Mipmaps improve rendering performance for textures viewed at varying distances but increase file size.

Quality Metrics (PSNR)

When enabled, Preflight computes PSNR (Peak Signal-to-Noise Ratio), MSE, and RMS metrics comparing the compressed texture against the original. Useful for validating that compression hasn’t degraded visual quality below acceptable thresholds.

Requires AppleTextureConverter (ships with Xcode).

Color Space

Optional fields for explicit color space conversion during export.

• Source: The color space of your input textures (e.g., DisplayP3).
• Output: The target color space (e.g., sRGB).

Leave blank to preserve the original color space. Only specify these when your pipeline requires an explicit gamut conversion.

Workflow Defaults

The Automatic setting adapts to your current workflow target:

Setting	OpenUSD	RealityKit
Format	PNG	AVIF
Quality	—	Fast
Max Size	Unlimited	4096 px
Mipmaps	Off	On
Quality Metrics	Off	On

AppleTextureConverter

GPU-accelerated texture compression is provided by AppleTextureConverter, which ships as part of Xcode. Preflight links it in-process (no subprocess spawning, sandbox-safe).

When available, it enables:

• ASTC and BC1–7 compression
• GPU-accelerated mipmap generation
• PSNR/MSE quality comparison
• Memory-to-memory conversion

If Xcode is not installed, Preflight falls back to open-source conversion backends. A status indicator in the Optimize Textures panel shows availability.

CLI

Texture optimization is also available through the command line:

# Analyze textures in a scene
preflighttool texture analyze scene.usdz --target RealityKit

# Convert a single texture
preflighttool texture convert albedo.png albedo.avif --format avif --quality best

# Export with current preferences
preflighttool export scene.usdz output.usdz --target RealityKit