> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lightcraft.pro/llms.txt
> Use this file to discover all available pages before exploring further.

# Objects

> Add 3D files to your scenes in supported formats and manage scene files

## Supported file formats

The Spark web app supports the following 3D object file formats:

* **USD** — Universal Scene Description
* **USDZ** — Compressed USD package

## Adding object files

<iframe src="https://player.vimeo.com/video/1221836713" width="640" height="360" frameborder="0" allowfullscreen />

Add 3D files to your scene through the outliner panel. Imported files appear in the scene hierarchy and can be positioned, rotated, and scaled using the transform tools.

## File caching

Imported files are cached for faster loading on subsequent visits. Large assets may take a moment to load the first time they are added to a scene.

## Scale

USD objects carry their own scale on import, separate from the location splat's scale, and it is not guaranteed to arrive correct. If an added object seems to be missing, check whether it actually loaded but at the wrong size before assuming the import failed.

## Preparing assets for the Spark web app

For best results, export USD objects with the MaterialX and USD Preview Surface materials when available.