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# open(rootLayer:sessionLayer:options:)

Opens a stage rooted at a given layer.

```
static func open(rootLayer: USDLayer, sessionLayer: USDLayer? = nil, options: USDStage.OpenOptions = []) throws -> USDStage
```

## Discussion

Recursively follows the composition rules described by `rootLayer`,
opening any files referenced by the layer and assembling a hierarchy of
[`USDPrim`](/documentation/USDKit/USDPrim)s from the combined contents of all layers.

This function creates a new, independent stage object even if there is
already a stage opened with `rootLayer` as its root layer.

Parameters:

- rootLayer: The root layer of the new stage.
- sessionLayer: A layer to use as a session layer. If `nil`, an anonymous layer will be created.
- options: Options that specify behavior related to opening a stage.

---

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