---
title: OpenUSD schemas for AR
framework: usd
role: article
role_heading: OpenUSD schemas for AR
path: usd/usd-schemas-for-ar
---

# OpenUSD schemas for AR

Add augmented reality functionality to your 3D content using USD schemas.

## Overview

Overview Universal Scene Description (USD) is a widely-supported specification for the interchange and storage of 3D graphic data. USD files are the preferred interchange format for apps displaying 3D and AR content using the ARKit and RealityKit frameworks. Apple, in collaboration with Pixar, developed a set of schemas to extend USD for AR use cases. These schemas, among other things, add the ability to: Anchor 3D content at a specific location in the real world. React to real-world situations. Participate in a physics simulation. Connect audio effects to a location. Annotate the environment by displaying text. These schemas allow you to include the data needed to support augmented reality features in AR Quick Look, and also let you use USD files in place of .reality files when writing RealityKit apps. Reality Composer Pro uses these schemas to store data for AR features, like anchoring, in its USDA scene files. To enable AR features in assets from a third-party digital content-creation (DCC) tool that doesn’t support these schemas, export the file as a .usda file using the USD Toolset and edit them by hand. note: These new schemas (see Schema definitions for third-party DCCs) are included in the Universal Scene Description specification as an addendum and are marked as preliminary. The addendum also adds metadata (name-value pairs; see Metadata), and new data properties (Property). To provide feedback on the addendum, use the Feedback Assistant. Implement AR functionality The following illustration depicts a virtual castle rendered by a runtime, the app or system framework that implements the AR functionality described in the schemas. The prim for the virtual castle (USD refers to individual units of 3D content as prims; see UsdPrim) instructs the runtime to place the castle on a known image in the physical environment, called the image anchor. When the user comes into proximity with the anchor, the runtime displays the 3D visualization of the castle. Falling snowflakes represent additional prims that behave as if in accordance with gravity, and disappear as they approach a real-world surface.

## Topics

### Animation

- [autoPlay](usd/autoplay.md)
- [playbackMode](usd/playbackmode.md)

### Anchoring

- [Placing a prim in the real world](usd/placing-a-prim-in-the-real-world.md)
- [Preliminary_AnchoringAPI](usd/preliminary-anchoringapi.md)
- [Preliminary_ReferenceImage](usd/preliminary-referenceimage.md)

### Behaviors

- [Actions and triggers](usd/actions-and-triggers.md)

### Text

- [Preliminary_Text](usd/preliminary-text.md)

### Scenes and lighting

- [Specifying a lighting environment in AR Quick Look](arkit/specifying-a-lighting-environment-in-ar-quick-look.md)
- [preferredIblVersion](usd/preferrediblversion.md)
- [sceneLibrary](usd/scenelibrary.md)

### Digital content creation

- [Schema definitions for third-party DCCs](usd/schema-definitions-for-third-party-dccs.md)

## See Also

### Essentials

- [Schema definitions for third-party DCCs](usd/schema-definitions-for-third-party-dccs.md)
- [Creating USD files for Apple devices](usd/creating-usd-files-for-apple-devices.md)
- [Validating feature support for USD files](usd/validating-usd-files.md)
- [Placing a prim in the real world](usd/placing-a-prim-in-the-real-world.md)
- [Previewing a Model with AR Quick Look](arkit/previewing-a-model-with-ar-quick-look.md)