usd-editor

Original：🇺🇸 English

Translated

Guide for modifying USD ASCII (.usda) files, including prims, properties, composition arcs, variants, and transforms. Use when editing or reviewing .usda files by hand.

12installs

Sourcetomkrikorian/visionosagents

Added on2026-02-07

NPX Install

npx skill4agent add tomkrikorian/visionosagents usd-editor

SKILL.md Content

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USD Editor

Description and Goals

This skill guides safe, minimal edits to USD ASCII (.usda) files and the proper use of USD command-line tools. It focuses on preserving stage structure, using correct specifiers and property types, and avoiding composition mistakes while making targeted changes.

Goals

Make precise edits without disrupting existing USD composition
Preserve file formatting and authoring style
Use correct prim specifiers, property types, and relationships
Avoid common USD pitfalls (wrong paths, missing xformOpOrder, broken connections)
Guide safe manipulation and inspection of USD assets using the command-line tools

What This Skill Should Do

When asked to modify a .usda file, this skill should:

Inspect the stage structure - Identify root prims, scopes, and relevant paths.
Choose the correct specifier - Use
```
over
```
for edits to existing prims,
```
def
```
for new prims.
Edit only what is necessary - Preserve unrelated content and formatting.
Respect composition - Avoid changing subLayers, references, or variants unless asked.
Validate connections and paths - Ensure
```
SdfPath
```
targets are valid and type-compatible.

If the change is material- or shader-related for RealityKit, prefer the

shadergraph-editor

skill for node-specific guidance.

Quick Start Workflow

Locate the prim path you need to edit (search by prim name or
```
SdfPath
```
).
Determine whether you should
```
over
```
an existing prim or
```
def
```
a new one.
Apply the smallest possible change (attribute value, relationship target, or child prim).
If adding transforms, update
```
xformOpOrder
```
to match your new ops.
Re-check any paths or connections you touched.

Information About the Skill

Core Concepts

Stage and Layer

A USD stage is composed of one or more layers. A .usda file is a single ASCII layer that can sublayer or reference others.

Prim and Specifier

A prim is a scene graph node. Specifiers control behavior:

def

creates,

over

modifies,

class

defines a reusable template.

Properties

Attributes store typed data; relationships (

rel

) point to other prims.

Composition Arc

Mechanisms like sublayers, references, and payloads that bring other USD data into the stage.

SdfPath

A path to a prim or property, written like

</Root/Child>

or

</Root/Mat.outputs:surface>

.

List Editing

USD list ops (

prepend

,

append

,

delete

,

add

) modify lists without replacing them.

Variants

Variant sets provide alternative content branches for a prim.

Time Samples

Animated or time-varying data stored in

timeSamples

dictionaries.

Reference Tables

Reference	When to Use
`usd-syntax`	When you need a refresher on .usda syntax, values, and path formats.
`prims-properties`	When adding or editing prims, attributes, or relationships.
`composition-variants`	When touching sublayers, references, payloads, or variant sets.
`transforms-units`	When editing transforms, xformOps, or stage units/up axis metadata.
`time-samples`	When modifying animated/time-sampled properties.
`command-line-tools`	When you need a quick reference for common USD command-line tools.
`usdcat`	When converting, flattening, or inspecting USD files.
`usdchecker`	When validating USD or USDZ assets, including RealityKit-focused checks.
`usdrecord`	When rendering images from USD files.
`usdtree`	When inspecting the prim hierarchy of a USD file.
`usdzip`	When creating or inspecting USDZ packages.
`usdcrush`	When compressing USD or USDZ assets for size.
`usdextract`	When extracting files from USD-compatible packages.

Implementation Patterns

Override an Existing Prim

usda

over "Mesh"
{
    token visibility = "invisible"
}

Add a Simple Xform with Translate

usda

def Xform "Pivot"
{
    double3 xformOp:translate = (0.0, 0.1, 0.0)
    uniform token[] xformOpOrder = ["xformOp:translate"]
}

Bind a Material Relationship

usda

rel material:binding = </Materials/Mat>

Pitfalls and Checks

Don't replace a prim with
```
def
```
when you only need an
```
over
```
.
Keep
```
xformOpOrder
```
consistent with the ops you add or remove.
Verify
```
SdfPath
```
targets exist and match the expected property type.
Avoid editing composition arcs unless explicitly requested.
Preserve existing formatting and comments to minimize diff noise.

usd-editor

NPX Install

Tags

SKILL.md Content

USD Editor

Description and Goals

Goals

What This Skill Should Do

Quick Start Workflow

Information About the Skill

Core Concepts

Stage and Layer

Prim and Specifier

Properties

Composition Arc

SdfPath

List Editing

Variants

Time Samples

Reference Tables

Implementation Patterns

Override an Existing Prim

Add a Simple Xform with Translate

Bind a Material Relationship

Pitfalls and Checks