Unity Playmaker VR XR - Trigger Particles when object thrown

Introduction

In this tutorial, we will learn how to use Unity with Playmaker VR to create an interactive game object that can be grabbed, thrown, and trigger a particle effect when it hits a target. This guide is especially useful for developers looking to enhance user feedback in VR environments.

Step 1: Adding XR Grab Interactable Component

1. Select Your Object: In your Unity scene, choose the object you want to make interactive (e.g., a can).
2. Add Component:
   • Navigate to the Inspector window.
   • Click on "Add Component."
   • Search for and select the "XR Grab Interactable" component.
3. Configure Interaction: Adjust the settings within the XR Grab Interactable component to suit your game's needs, such as grab distance and interaction settings.

Step 2: Hiding Hands When Picking Up an Item

1. Locate Hand Models: Identify the hand models used in your VR setup.
2. Set Up Visibility:
   • Create a new event in Playmaker that triggers when the object is grabbed.
   • Use an action that sets the visibility of the hand models to false when the object is picked up.
3. Testing: Playtest to ensure hands disappear as expected when the object is grabbed.

Step 3: Setting Up the Trigger on Top of the Can

1. Add a Collider:
   • Select the can object.
   • Add a collider component (e.g., Box Collider) that will serve as the trigger area.
2. Configure Collider:
   • Ensure the collider is set as a trigger by checking the "Is Trigger" option in the collider settings.
3. Positioning: Adjust the size and position of the collider to fit the top of the can where the paper will land.

Step 4: Creating Particle Effects

1. Add Particle System:
   • In the hierarchy, right-click and select "Effects" > "Particle System."
   • Position the particle system above the can to ensure it emits when triggered.
2. Configure Particle Effects:
   • Customize the particle system settings (e.g., duration, start size, color) to create the desired effect.
3. Testing: Ensure the particle system is visible and behaves as expected in the game view.

Step 5: Setting Up Playmaker FSM Trigger Event

1. Create FSM:
   • Add a new Playmaker FSM to the can object.
   • Name it something relevant, like "CanTriggerFSM."
2. Add States:
   • Create a new state for detecting the trigger event.
   • Use the "Trigger Event" action to detect when the paper enters the collider.
3. Link to Particle System:
   • In the FSM, create a transition that activates the particle system when the trigger event occurs.

Step 6: Activating the Particle System

1. Add Action to FSM:
   • In the state created for the trigger event, add an action to play the particle system.
   • Use the action "Send Message" or "Enable Game Object" to activate the particle effect.
2. Testing: Test throwing the paper at the can to see if the particle effect activates correctly upon impact.

Step 7: Destroying the Paper Object

1. Add Destroy Action:
   • In the same FSM state, after triggering the particle effect, add an action to destroy the paper object.
   • Use the action "Destroy Object" to remove the paper from the game.
2. Testing: Ensure that the paper disappears once it has triggered the particle effect.

Conclusion

In this tutorial, we successfully set up an interactive object in Unity using Playmaker VR. You learned how to:

• Create a grab-interactive object.
• Hide hand models during interaction.
• Set up triggers and particle effects to enhance player feedback.

Next steps could include refining the particle effects, adding more interactive elements, or exploring other aspects of VR development in Unity. Happy developing!