# Utility Classes

Following are some utility classes that used in combination with Tutorial Manager.

## 1. HSVMainTimer

Runtime action running manager. Used by Tutorial Manager to perform time related actions.

## 2. HSVObjectPool

Runtime pooling for performance purpose.

## 3. HSVTargetTrigger&#x20;

You could use this component to add scene object into Targets of Tutorial Object on runtime.

* **Stage Index**: Index of Stage Object that Tutorial Object belongs to.
* **Tutorial Index**: Index of Tutorial Object that this target belongs to.
* **Target Config**: The configuration of this target used by modules. Please refer to [#3.-targets](https://hsv-studio.gitbook.io/tutorial-factory/tutorials-objects#3.-targets "mention")

## 4. HSVTriggerObject

Tutorial Manager would add this component to the Target objects when playing Stage/Tutorial Objects on runtime. This component is used to trigger Stage/Tutorial start or stop events.

* **Collider Config**: Collider config of Start/End Trigger of Stage/Tutorial Object.
* **Graphic Config**: Graphic config of Start/End Trigger of Stage/Tutorial Object.
* **IsStartTrigger**: Is this trigger object used to Start or End event.
* **IsStage**: Is this trigger object used by Stage or Tutorial Object.
