---
title: masters
framework: modelio
role: symbol
role_heading: Instance Property
path: modelio/mdlasset/masters
---

# masters

An array of objects that can be reused in the asset’s object hierarchy through instancing.

## Declaration

```swift
var masters: any MDLObjectContainerComponent { get set }
```

## Discussion

Discussion Some asset formats supported by Model I/O provide instancing, a feature where the asset provides a single definition for an object, then can reuse that definition at multiple points in a scene. For example, an asset describing a scene of a table and chairs could contain mesh and material data for only one chair, then use instancing to place several of the same chair around the table. If an object loaded from an asset is an instance of one of that asset’s primary objects, that object’s instance property refers to the primary object.

## See Also

### Working with Asset Content

- [object(at:)](modelio/mdlasset/object(at:).md)
- [subscript(_:)](modelio/mdlasset/subscript(_:).md)
- [count](modelio/mdlasset/count.md)
- [childObjects(of:)](modelio/mdlasset/childobjects(of:).md)
- [add(_:)](modelio/mdlasset/add(_:).md)
- [remove(_:)](modelio/mdlasset/remove(_:).md)
- [boundingBox](modelio/mdlasset/boundingbox.md)
- [boundingBox(atTime:)](modelio/mdlasset/boundingbox(attime:).md)
- [url](modelio/mdlasset/url.md)
- [bufferAllocator](modelio/mdlasset/bufferallocator.md)
- [vertexDescriptor](modelio/mdlasset/vertexdescriptor.md)