AR and 3D glossary
In short: This glossary defines the terms you meet when making AR models for phones and websites, in one or two sentences each. Terms are grouped into file formats, viewers and how models are made.
File formats
| Term | Meaning |
|---|---|
| USD | Universal Scene Description, Pixar's open format for describing 3D scenes. |
| USDA / USDC | The text (USDA) and binary (USDC) forms of a USD file. |
| USDZ | A USD scene and its textures in one uncompressed zip file; Apple's AR format. |
| glTF | GL Transmission Format by the Khronos Group, an open format for delivering 3D models, often called the JPEG of 3D. |
| GLB | The binary, single-file form of glTF 2.0. |
| OBJ | An older text 3D format for geometry, with materials in a separate .mtl file. |
| Reality file | Apple's .reality format from Reality Composer, for AR scenes with behaviors. |
Viewers and platforms
| Term | Meaning |
|---|---|
| AR Quick Look | Apple's built-in AR viewer on iPhone, iPad and Vision Pro; opens USDZ. |
| Scene Viewer | Google's AR viewer on Android; opens GLB and glTF. |
| model-viewer | A free web component by Google that shows GLB models on a web page and starts AR on phones. |
| WebXR | A web standard that lets browsers run AR and VR sessions. |
| ARKit / ARCore | Apple's and Google's AR frameworks; a phone must support one of them for AR. |
Making models
| Term | Meaning |
|---|---|
| Photogrammetry | Building a 3D model from many overlapping photos or video frames of an object. |
| Object Capture | Apple's photogrammetry technology in RealityKit. |
| LiDAR | A depth sensor on some iPhones and iPads that measures distance with light. |
| Mesh | The surface of a 3D model, made of triangles (polygons). |
| Texture | An image wrapped onto a mesh to give it color and detail. |
| PBR | Physically based rendering: materials described by color, roughness and metalness so they look right under any light. |
| Real-world scale | A model stored at its true size, so it appears at that size in AR. |
| Gaussian splatting | A newer way to capture scenes as millions of soft points instead of a mesh; not supported by AR Quick Look. |
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Turn a photo into a real-size USDZ and GLB in a few seconds, or a video into a 3D model. Your first photo conversion is free.
USDZ ConverterFAQ
What is the difference between AR and 3D?
A 3D model is the object; AR is showing that object in your real surroundings through a camera.
Which format should I use for AR on all phones?
Both USDZ (iPhone) and GLB (Android and web). jpgtousdz creates both from one upload.