In many cases applications will need to filter 3D nodes by some custom data source or mechanism. This is done by extending the NodeCollectionBase-class. This class generates an IndexSet and provides notification when the set has changed. Implementations should be non-blocking - slow operations should be executed async and the set should be incrementally updated to avoid blocking the viewer.

Simple, static node collection

Live Editor

See also guide on (de)serializing node collections.

Details about IndexSet

IndexSet is a specialized implementation of Set<number> that is optimized for storing ranges of numbers. This is a common case for nodes as typically a subtree will have the same styling applied.

Although IndexSet supports adding and removing individual elements using add() and remove(), the best performance is achieved by using addRange() and removeRange() whenever possible.

Also note that changes to the underlying IndexSet held by a NodeCollectionBase isn't automatically propagated to be visible in the rendered result. In order to trigger an update after changing the underlying IndexSet, use NodeCollectionBase.notifyChanged() (protected function). Note that this function should not be triggered too often as it might take some time to apply the changes.