Instance Property


A component that manages this object’s collection of children.


@property(nonatomic, retain) id<MDLObjectContainerComponent> children;


Many asset formats describe a hierarchy of transforms that model the spatial relationships between meshes, lights, and cameras in the asset. In such formats, hierarchic transforms are MDLObject instances whose children property references the objects affected by the transform, and those objects can be other MDLObject instances with children of their own.

This property’s value is a component object—either a MDLObjectContainer instance, or a custom class that adopts the MDLObjectContainerComponent protocol. By default, an object has no container component (that is, this property’s value is nil). To add a container component, either write to this property an instance of a container component class or call the addChild: method to create a default MDLObjectContainer instance and add a child object to that container.

Container components support fast enumeration and subscripting, so you can treat an object’s children property similarly to an array.

See Also

Working with Object Hierarchies


The parent object that contains this object.

- addChild:

Adds a child object to this object, creating a container for the object’s children if necessary.

- enumerateChildObjectsOfClass:root:usingBlock:stopPointer:

Executes the specified block using each object in this object's child hierarchy.


A path that identifies the object in an asset's object hierarchy using object names.

- objectAtPath:

Returns the child object at the specified path.

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

Learn more about using Apple's beta software