Experimental: This feature is currently experimental and is subject to change in later major versions. To use this feature, enable Experimental Operators/Blocks in the Visual Effects tab of your Project's Preferences.

# Spawner Callbacks Spawner Callbacks is a C# API that allows you to define custom runtime behavior and create new Blocks for use in Spawn Contexts. Spawner Callbacks allow you to: * Control the Spawn Context state (Playing, Stopped, Delayed). * Read/Write the Output Spawn Count. * Read/Write SpawnEvent Attributes. ## Writing Spawner Callbacks The full Spawner Callbacks API reference is available [here](https://docs.unity3d.com/2019.3/Documentation/ScriptReference/VFX.VFXSpawnerCallbacks.html).