Tutorial

Introduction

This interaction system is designed to be flexible and easily extendable to handle any common or game specific interaction.
In this tutorial we will learn how to create a simple door interaction then create specific behaviors like adding requirements.

Create project

Create a new project based on Third person template

Install the plugin

Ensure the plugin is correctly installed and enabled

Collisions

Then we will need to configure collisions for physical interactions.

Create a New Trace Channel named Interact.
We set the default response to Ignore so we can manually choose the actors that will respond to our interactions

Tags

You can create new tags to organize actions and slots for your project or use existing ones.
For this example, we will create a primary action and a slot for our door lock.

Go to the gameplay tag manager and create two news tags:
- Interact.Action.Primary that represents our main interact action (we will bind the input later)
- Interact.Slots.Lock that physically represents our Lock

Info

See Concepts for more informations about Actions and Slots

Inputs

Now we need to create an input action and a mapping context for our interactions.

Create IA_Interact and IMC_Interact then bind the E key to IA_Interact

Info

You can use a single mapping context but for a better architecture, we put our interaction inputs in a separated mapping context

Then we will map our interact actions to the input system.

Create a data asset using the class NIS Action Mapping Asset named DA_InteractMapping

Name the action Interact and set the created input action IA_Interact

Settings

Go to Project settings > Game > NIS Settings
- Set the default collision channel to Interact
- Set the action slot to Interact.Action.Primary
- Set the interact action mapping to DA_InteractMapping

Info

An action can bind to one or multiple slot. Here we have a simple configuration where our primary action will use the default slot. Those bindings can be configured per interact component for more complex configurations

Interactor (player)

To interact, we need an interactor (it could be a player or an AI).

Create a new PlayerController blueprint named B_PlayerController and set it in the game mode settings

Open it and add a new component, select NIS Player Interactor

Configure the player interactor to use the range scanner and set the input mapping context we created (IMC_Interact)

Info

You can visualize the scanner by enabling the debug mode in NIS settings

Interact (door)

Now that we have a player that can interact, we can create our door. We will need an interact component, a slot, and an indicator

Create a new blueprint named B_Door

• Create a mesh slot that will represent our door

• Configure its collision by selecting a mesh and check the Interact trace response after selecting Custom in Collisions Presets

Info

We will see later how to configure slots to create advanced interactions

• Create an interact component to write the logic of our interaction, select NIS Interact Instant

Info

The instant interact is a type of interaction that will end directly. See Architecture to understand the interaction process

The interact component has many events, add the OnInteract event.

We make a simple code to open vertically the door and close it

Requirements

Now that we have a basic interaction, we will use the requirement system to unlock the door only if our player has a specific key.

First we store a KeyId variable in our B_PlayerController

Info

In a real game we would store those kind of variables in a better place

Then we store a KeyId for our B_Door. Don't forget to set it Instance editable so you can change the KeyId of door instances in the world.

We create our KeyRequirement to do so, create a new blueprint class inheriting from NIS_RequirementBase named B_KeyRequirement

A requirement has two implementable functions:
- Check : returns true if the interactor meet the requirements
- GetText : returns the text to display if the requirement failed

We write a Check function that will compare the KeyId of the door and the KeyId of the player to know if the player meet the requirements and can interact with the door.

To test what we have done:
- Set the player KeyId to 1
- Create one door A with a KeyId of 1
- Create one door B with a KeyId of 2
- Try to open both doors, only the door A will open

But we don't have any feedback when the door is locked. To add a message when a requirement fails, that's very simple, just add the interact component event OnInteractRequirementsFailure.
We only get the first element because we have only one requirement, but you could get all errors if you use multiple requirements.