Step 4: Character - Tags

Goal

• Understand Tag System and how it forms a State Machine

Review

So far, you've learned how Input Tags are used to trigger Action States and allowed the penguin to attack. However, you may wonder how different Action States could be triggered by the same Player Input (i.e. A light attack combo all triggered by left clicking). They are using the same input but should be different Action States. How do I control which State to trigger?

In this Step, we will discuss the Tag System and the Dynamic State Machine in Penguin Action Toolkit.

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Tag System

In PAT, Tags serve as tickets for the character to enter different Action States. Action States are triggered by corresponding Input Tags, but they also request a list of Require Tags in order to be entered. If they cannot find the required tags in Tag Container, the Action State cannot be entered.

Attack1 requires character to have Idle Tag

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Inspector

• Require Tags

  After receiving the corresponding Input Tag, State A will check if the character is currently holding the Required Tags before entering. If not, nothing will happen.

  • The relationship among outer Elements is logical disjunction (or).

    As long as one element has all of its requirements fulfilled, this is considered to be true, and the State can be entered.

  • The relationship among inner Elements is logical conjunction (and).

    All requirement tags must be present, or the "no requirement" box is checked for this element to be considered true.

You can add new Tags into the Require Tags of Attack1, and you will find the penguin unable to attack again.

After entering the Action State, the State will also grant tags to the character. All tags in the Main Tags field will be added to the Tag Container.

• Main Tags Tags a character will hold if it is in this State

Apart from the things we mentioned, there are other usage of Tags to control state transitions. You can find the following fields in the inspector of Action State components.

• Prohibit Tags If another State tries to enter when character is in State A, and at least one of its Main Tags is listed in State A’s Prohibit Tags, it cannot be entered.

• Self-Prohibit Tags If the character is in another State and is currently holding any Tag listed in State A’s Self-Prohibit Tags, State A cannot be entered.

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Further Reading

You may find full documentation on Action State's inspector details by the following link. It is quite useful when creating your own Action State.

Action State