GuideKit

Game Development

Unreal Engine 5 interaction system for gameplay objects

Build a basic UE5 interaction system with Blueprints, a trigger box, and contextual animation so a character can pick up or use gameplay objects.

GuideKit EditorialEditorial team
7 min read
A gray humanoid character stands beside a white rectangular chest in a simple gray and green 3D level.
A character stands next to a white chest in a gray-and-green 3D test level. — footage: All things GAME!

To set up an interaction system in Unreal Engine 5, enable the contextual animation and motion warping plugins, create a Blueprint for your target object with a trigger box, and wire up your character to detect and respond to the trigger. Use contextual anim scene and roles assets to synchronize the animation, and call the contextual animation scene from an input event when the character is in range.

What you need before you start

prerequisites

  • Enable the contextual animation plugin and motion warping plugin from the Plugins window.
  • Open the level where you will test the interaction system.
  • Create an Actor Blueprint for your gameplay object (e.g., a loot chest).
  • Add a skeletal mesh (for the object visuals) and add a trigger box (for interaction detection) to the object Blueprint.
  • Open your third person character Blueprint and add a can interact with object boolean variable.
  • Add a contextual anim scene actor component and a motion warping component to both the character and the object setup.

Unreal Engine editor with the Plugins window open over the level viewport, showing the all plugins list and a search bar.

The Plugins window is open inside the Unreal Engine editor, with the plugin list visible. — All things GAME!

Build the gameplay object with a trigger

steps

  1. In your object Blueprint (e.g., BP_LootChest), ensure you have a skeletal mesh for the object and a trigger box component for detecting overlaps.
  2. Open the Event Graph in the object Blueprint and add events for OnActorBeginOverlap and OnActorEndOverlap.
  3. When an actor begins overlap with the trigger box, set the player's can interact with object variable to true (you may need to cast to the character class).
  4. When the actor leaves the trigger, set can interact with object to false.
  5. The interaction logic is best kept on the character’s side; the object only marks itself as interactable.

Unreal Engine Blueprint editor is open on BP_LootChest with the Components panel on the left and an empty viewport in the center.

The Blueprint editor shows BP_LootChest with only the default scene root in the Components panel. — All things GAME!

Set up the contextual animation assets

steps

  1. Add a contextual anim scene component to your object or to a suitable actor (name it for the relevant interaction, such as LootItem).
  2. Create a new contextual anim roles asset: In the Content Browser, right-click, choose Data Asset, then pick the contextual anim roles asset type. Name it clearly.
  3. Add two roles: one for the Player and one for the Object. Click Update Roles after adding.
  4. Create the animation montage in your animation folder based on your desired interaction animation (e.g., opening a chest).
  5. In the contextual anim scene asset, assign the Player as the primary role and mark it as a character.
  6. In the mesh-to-component and mesh-to-scene offset fields, adjust values as needed to align the animation preview (e.g., Z offset -90).

Unreal Engine editor with the Content Browser open to ContextualAnims/Loot, showing a Cas_LootItem contextual animation data asset and a small asset creation popup in the viewport.

The Unreal Engine Content Browser is open to the ContextualAnims/Loot folder, with a Cas_LootItem contextual animation data asset visible. — All things GAME!

Add motion warping and preview the object together

steps

  1. In the montage for your interaction, add a motion warping notify at the very start.
  2. Set the warp target name to match your player role.
  3. In the contextual anim scene, add a walk point definition: set the Player mode to Custom and set the origin to Object.
  4. Add a definition for the Object with the target name set to object and use the primary actor.
  5. Override preview data so both the player and the object appear in the preview. Assign the loot chest class to the object’s preview role.
  6. Click reset scene after updating the preview and offsets to refresh the visualization.

Unreal Engine animation editor showing a character standing in the preview scene with an object target visible, plus timeline and asset details panels.

The animation editor shows the preview scene with the character and object together while the motion warping settings are open. — All things GAME!

Wire the input to start the interaction

steps

  1. In your character Blueprint, bind a keyboard input event (such as the "E" key).
  2. On key press, branch on whether can interact with object is true.
  3. Check that the stored object reference is valid.
  4. If both are true, create contextual anim bindings:
    • Create a map with two entries: player and object.
    • Use a self reference for the player binding.
    • Use the object reference for the object binding.
  5. Call Start Contextual Anim on the contextual animator component, passing the binding map.
  6. Test in editor: walk into the trigger, press E, and see if the interaction animation plays.

Unreal Engine Blueprint EventGraph with several connected nodes open in the editor.

The Blueprint EventGraph is open with multiple nodes wired together. — All things GAME!

Tighten the alignment and finish the pickup system

before after

Before

Initial Alignment

  • The character may stand slightly too far away, or not face the object correctly.
  • The collision area for the interaction might be on the wrong side of the object.
  • Test the interaction and notice if the animation looks out of sync.
After

Improved Alignment

  • Adjust the mesh-to-scene or mesh offset for the player role in the contextual anim scene. Increase the Y or further tweak Z/Y as needed and hit reset scene after each change.
  • Move the trigger box or object collision to the correct area so the character interacts from the right spot.
  • After each adjustment, test in play mode. The character should rotate and align with the object and perform the animation sequence smoothly.
  • If you want the object (like a chest) to animate too, add a play animation node on the object Blueprint when interaction occurs.

Unreal Engine animation preview window with a character standing beside a white block, a timeline at the bottom, and asset details and preview settings panels on the right.

Unreal Engine shows a character preview scene with timeline controls and section settings open for adjusting an animation setup. — All things GAME!

Also worth knowing

  • Reusable setup: This interaction system structure can be reused for different gameplay objects, such as doors, boxes, buttons, and levers.
  • Height variation: For pickups on different elevations, adjust the mesh or interaction offsets in the contextual animation asset.
  • Character alignment issues: If your character rotates the wrong way after an interaction, check and adjust the rotation and reset options on the interaction actor.
  • Interaction not triggering: If the animation doesn't play, check your Blueprint chain and ensure the interaction variables and bindings are correctly set up.

FAQ

Unreal Engine 5 character interaction tutorial

To build a character interaction system, start by enabling the necessary plugins, create an actor with a trigger, and set up contextual animation assets, then tie the interaction logic to an input key in the character Blueprint.

how to interact with objects in UE5

Place a trigger box on your target object, detect when the character enters the trigger, set a variable to allow interaction, and handle the interaction logic and animation when the player presses the designated input key.

UE5 pickup and trigger system

Combine a trigger box with overlap events to mark when the character can perform an action. Use contextual animation to handle synchronized pickup sequences or other interactions when the input is pressed.

beginner interaction system Unreal Engine

A simple interaction system requires a trigger box, a boolean variable to check whether interaction is allowed, basic Blueprint logic, and use of contextual animation for a clean interaction sequence.

Unreal Engine 5 gameplay interaction guide

The outlined system lets you interact with objects, trigger pickups, and play synchronized animation using built-in UE5 components and Blueprints. You can extend this setup to other gameplay objects or use interfaces for even more flexibility.

Official reference: Unreal Engine documentation.

Related guides

Sources

Screenshots on this page are frames from the videos below, used to illustrate the steps they describe. All rights remain with their creators.

Checked against:

On this page

Continue reading

Game Development

Unreal Engine Beginner Tutorial: Set Up a Third-Person Controller

Create the input actions, controller blueprint, character blueprint, and game mode needed for a playable third-person character in Unreal Engine. Then wire movement and camera control, assign the character to the project, and test the result in Play.

Read

Game Development

Godot Collision and Physics Movement: Push RigidBody2D Objects Without Breaking the Level

Set up Godot collision layers for a CharacterBody2D, then fix rigid body pushing by applying an impulse in code instead of letting the player plow through physics objects.

Read

Game Development

Godot 4 First-Person Controller Movement Setup

Build a basic Godot 4 first-person controller by wiring input actions, adding player movement physics, and driving mouse look from a camera rig.

Read