MX Ink 2D Drawing Sample

Overview

This Unity project allows users to create a 2D drawing canvas in a mixed reality (MR) environment using spatial anchors and interact with it using a stylus on the Meta Quest. Users can:

• Place spatial anchors to define the corners of the drawing canvas.
• Automatically generate a canvas from the anchors.
• Draw on the canvas with varying line widths.
• Save and reload anchors and the canvas across sessions.
• Undo or clear drawn lines with stylus interactions.

Features

1. Spatial Anchor Placement

• Stylus Tip Press: Press the stylus tip (pressure > 0.98) near the desired position to create up to 3 anchors.
• Canvas Generation: After placing 3 anchors, the next stylus press creates a canvas defined by those anchors.

2. Drawing on Canvas

• Stylus Drawing: Draw on the canvas by pressing the stylus tip.
• Dynamic Line Width: Line thickness adjusts based on pressure.

3. Undo and Clear Drawings

• Undo Last Line: Double-tap the stylus back button or press it once to undo the last line.
• Clear All Lines: Hold the stylus back button for more than 1 second to erase all drawings.

4. Anchor and Canvas Persistence

• Save: Anchors and canvas positions are automatically saved using PlayerPrefs.
• Reload: Press the Y button (left controller) to reload the saved anchors and canvas.
• Reset: Press the X button (left controller) to reset and clear all anchors and canvas.

Key Bindings & Controls

Control	Action
Stylus Tip Press (Pressure > 0.98)	Create anchors or generate canvas
Stylus Draw on Canvas	Start/continue drawing
Stylus Back Button (Double Tap)	Undo the last drawn line
Stylus Back Button (Hold 1s)	Clear all drawings
Left Controller - X Button	Reset anchors and canvas
Left Controller - Y Button	Reload saved anchors and canvas

Project Structure

• CanvasSetupManager.cs: Handles the creation of spatial anchors, canvas generation, saving, and loading of anchors.
• LineDrawing.cs: Manages line drawing on the canvas, including undo/clear functionality.
• StylusHandler.cs: Tracks stylus input (pressure, button presses, pose).
• Prefabs: Contains the anchor and canvas prefabs.
• Materials: Defines line and canvas appearance.

Setup Instructions

1. Clone the Repository:

   git clone https://github.com/ftmghorbani/MX_Ink_2Ddrawing_Sample.git

2. Open in Unity:

   • Open the project in Unity Editor (version 2022.3.50f1 or compatible).

3. Configure Oculus XR:

   • Ensure Oculus XR Plugin is enabled.
   • Set up Android build target for Oculus Quest.

4. Run the Project:

   • Connect the Oculus Quest via ADB.
   • Press Play in Unity or build and deploy to the headset.

Prerequisites for Spatial Anchors

This project requires the setup of Meta Spatial Anchors. For detailed instructions, refer to the official Meta documentation: Unity Spatial Anchors.

Credits

Developed in collaboration with Logitech, based on the official Logitech MX Ink Unity Integration Guide and the Logitech MX Ink Official Sample.