2023 Unity VR Basics – XR Hands

Summary

This tutorial guides viewers through implementing hand tracking in VR using Unity's XR Hands package. It covers installing the package, setting up hand visualization, and configuring hand tracking in Unity's project settings. The video demonstrates how to switch between XR hands and controllers using the XR Input Modality Manager and addresses a common bug when switching. It also shows how to set up direct interaction with objects using the XR Direct Interactor and XR Grab Interactable, highlighting the use of dynamic attachment for natural grabbing. The presenter encourages experimentation with the new XR hands feature, despite its current bugs, and thanks Patreon supporters.

Takeaways

• 😎 Implementing XR hands in Unity requires installing the XR Hands package and importing a hand visualizer for basic components.
• 🔧 To enable hand tracking, add 'Hand Tracking Subsystem' and 'Meta Hand Tracking Aim' in the Project Settings under OpenXR.
• 🖐️ Set up the Hand Visualizer component under an 'XR hands' empty object, which includes references to the XR origin and specific hand meshes.
• 🎨 Customize hand appearance by assigning materials and choosing whether to display the hand mesh in the game.
• 👀 Debugging features like joint visualization and velocity tracking can be enabled to understand hand tracking dynamics.
• 🤚 Addressing the issue of controller hands following the user, use the 'XR Input Modality Manager' to switch between XR hands and controllers.
• 👉 Create empty game objects for left and right hands and assign them to the XR Input Modality Manager for proper interaction.
• 🛠️ To fix bugs when switching between controllers and hand tracking, consider using a neutral controller representation or avoid swapping until issues are resolved.
• 🤏 Set up 'XR Direct Interactor' for grabbing objects with XR hands, adjusting the position to the pinch point for natural interaction.
• 🔄 Use 'Dynamic Attach' in the 'XR Grab Interactable' to allow objects to be grabbed precisely where the hand pinches, enhancing realism.
• 🎮 The tutorial suggests experimenting with XR hands, acknowledging some bugs but highlighting the potential of hand tracking with the XR Interaction Toolkit.

Q & A

What is one of the coolest experiences in VR that the script discusses?

One of the coolest experiences in VR discussed is using hand tracking and XR hands.

How does the script suggest to implement XR hands in a Unity project?

To implement XR hands, the script suggests installing the XR Hands package from the Unity registry and importing a hand visualizer.

What additional settings are required in Unity's project settings to enable hand tracking?

In Unity's project settings, you need to add the Hand Tracking subsystem and the Meta Hand Tracking Aim under OpenXR.

What is the purpose of the Hand Visualizer component mentioned in the script?

The Hand Visualizer component is used to visualize and represent the XR hands in the VR environment.

How does the script recommend setting up the XR hands in the scene hierarchy?

The script recommends creating an empty object called 'XR hands' and placing all XR hand-related components under this as children.

What meshes are used for the left and right hands in the script's example?

The script uses different meshes for the left and right hands that have their own unique bone structure, which can be found in the 'XR hands 1.1.0' package under 'visualizer models'.

Why does the script suggest adding a 'Debug Draw Prefab' to the Hand Visualizer?

The 'Debug Draw Prefab' is suggested to visualize the joints and velocity of the hands in play mode, aiding in debugging and development.

What is the XR Input Modality Manager and how does it relate to swapping between XR hands and controllers?

The XR Input Modality Manager is used to manage the input modality, allowing for swapping between XR hands and controllers in the VR experience.

What issue does the script highlight when switching between XR hands and controllers?

The script highlights a bug where the hand might remain in a curved position even after picking up controllers, indicating a need for further refinement in the XR hands feature.

How can the issue of hands remaining in a curved position be mitigated according to the script?

The script suggests using a neutral device representation for the controllers or avoiding swapping between controllers and XR hands until the bug is fixed.

What is the 'XR Direct Interactor' and how is it used in the script?

The 'XR Direct Interactor' is used to enable grabbing and interacting with objects in the VR environment using the XR hands, requiring a collider and an XR controller component.

How does the script recommend setting up the position of the XR Direct Interactor?

The script recommends setting the position of the XR Direct Interactor to 'pinch' so that it moves to the very tip of the fingers when hand tracking is active.

What does the script suggest for making object grabbing with XR hands look more natural?

The script suggests using 'Dynamic Attach' in the XR Grab Interactable to allow grabbing objects right where the pinch occurs, making the interaction feel more natural.