Grabbable Objects

The Grabbable Objects module allows users to pick up, carry, and release objects with hand-tracking input, handling physics toggling and network synchronization seamlessly .

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Overview

• Registers grabbable objects and listens for hand grab/release events via the EventManager.
• On grab: parents the object to the hand, disables physics and gravity, and applies optional position/rotation offsets.
• On release: re-enables physics, unparents the object, and—if enabled—syncs the final transform across the network when the rigidbody sleeps.
• Automatic singleton manager ensures minimal setup: the manager is created on first use if not present.

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Requirements

• Unity 2022.3 LTS or later
• New Input System
• XR Interaction Toolkit
• HoloMIT Core & EventManager (EventManagerController and MessageTypeID support)

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Configuration

1. Make any GameObject grabbable:

   • Attach the Grabbable component.
   • (Optional) Enable UseOffsets and configure:
     • GrabPositionOffsetLeft/Right
     • GrabRotationOffsetLeft/Right
   • (Optional) Enable ForceSleepSync to send a sync message when the rigidbody goes to sleep.

   

2. Ensure the Manager is in scene:

   • The GrabbableObjectManager singleton auto-instantiates on first RegisterGrabbable call.

   

3. Configure HandController

   • Add the HandController script to each hand GameObject.

   

   • Add the HandInteractionManager script to each hand GameObject.

   

   • Assign the GrabCollider prefab in the Inspector.

   

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Usage

• Grab: Press the Trigger and Grab inputs simultaneously. The object will be positioned on the hand's GameObject.

  

• Release: Release the Trigger or Grab inputs. Physics reactivates, the object detaches, and, if ForceSleepSync is true, its final transformation is synchronized when the rigid body comes to rest.

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