Unity VR: Setting Up Grabbable Objects
Intro
If you have Ray Interactors setup on your VR controllers in the XR Origin rig, it would be nice to put it to use and give them the ability to pick up some things. In order for an object to become “Grabbable” it will need 3 things:
- Collider
- Rigidbody
- XR Grab Interactable
Collider
You will need to add a Collider (Box, Sphere, Capsule, or Mesh Collider) to the GameObject you would want to make grabbable. The Collider is needed because it defines the physical boundaries for the Interaction. Without a Collider, the Interactor has no detecting the object.
Just make sure “Is Trigger” is unchecked so it can be physically grabbed.
Rigidbody
The Rigidbody component tells Unity’s physics engine to simulate motion, gravity, and collisions on the object. Without it, the object is considered static and won’t move or respond when grabbed or thrown.
Set “Use Gravity” and “Is Kinematic” based on how you want it to behave when released.
- If you’re using Throwing, uncheck Is Kinematic.
- If the object should just stick where placed, keep it Kinematic.
XR Grab Interactable
This marks the object as grabbable by XR Interactors (like controllers or hands). Interactors (like your VR hands or ray controllers) use raycasts to detect objects, and this detection only works if the object has a Collider as it outlines where the user must point or touch to interact with the object.
Also, the XR Grab Interactable also uses the Rigidbody and works with it to move the grabbed object to follow the hand/controller. The Rigidbody allows Unity to move that object within the physics system.
Conclusion
Setting up grabbable objects in your VR experience using the XR Interaction Toolkit is straightforward once you understand the key components involved. A Collider defines the physical boundaries for interaction, a Rigidbody enables realistic physics and motion, and the XR Grab Interactable ties everything together to allow interaction through VR controllers.
