kienbui1995/xr-interface-design

XR Interface Design

When to Use

When building user interfaces for augmented reality, virtual reality, or mixed reality experiences.

Core Jobs

1. Input Modality Selection

Choose the right input for each interaction: | Modality | Use When | Avoid When | |----------|---------|-----------| | Gaze + dwell | Hands occupied, accessibility | Fast interactions (too slow) | | Hand tracking | Natural, markerless | Precise targets < 2cm | | Controller | Precision, gaming | Markerless consumer AR | | Voice | Quick commands, eyes-free | Noisy environments, private | | Spatial tap (visionOS) | Natural selection | Complex gestures |

Prefer direct manipulation (touch the thing) over raycast menus where possible.

2. Spatial UI Placement

• Arm's length zone (0.5–2m): optimal for readable, interactive UI
• Too close (< 0.5m): causes eye strain, uncomfortable
• Too far (> 3m): hard to read, hard to interact with
• World-locked: UI stays in the world (good for contextual info)
• Head-locked: UI follows the user (use sparingly — causes motion sickness)
• Body-locked: locked to body position but not rotation (good compromise)

3. Comfort Guidelines

• No interaction requiring sustained arm elevation (gorilla arm fatigue)
• Minimum interaction target size: 2cm × 2cm at interaction distance
• Depth conflicts: avoid placing UI that competes visually with real world objects in AR
• Frame rate: VR must target 72fps minimum (90fps preferred); drops cause motion sickness

4. Adapt 2D Patterns for 3D

• Replace dropdown menus with radial menus or spatial panels
• Replace hover states with proximity highlight (gaze or hand approach)
• Replace modals with spatial overlays that don't block the world
• Depth cue for hierarchy: closer elements = foreground = more important

Key Outputs

• Input modality map (what triggers what)
• Spatial placement spec
• Comfort review checklist
• 2D to 3D adaptation guide

Anti-Patterns

• Porting 2D UI directly into 3D space (flat UI panels floating in space)
• Head-locked menus for anything other than critical HUD
• Interaction targets below minimum size
• No affordance for the interaction mode (users don't know what's interactive)