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name: vr-ar description: VR/AR development principles. Comfort, interaction, performance requirements. allowed-tools: Read, Write, Edit, Glob, Grep

VR/AR Development

Immersive experience principles.

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1. Platform Selection

VR Platforms

| Platform | Use Case | |----------|----------| | Quest | Standalone, wireless | | PCVR | High fidelity | | PSVR | Console market | | WebXR | Browser-based |

AR Platforms

| Platform | Use Case | |----------|----------| | ARKit | iOS devices | | ARCore | Android devices | | WebXR | Browser AR | | HoloLens | Enterprise |

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2. Comfort Principles

Motion Sickness Prevention

| Cause | Solution | |-------|----------| | Locomotion | Teleport, snap turn | | Low FPS | Maintain 90 FPS | | Camera shake | Avoid or minimize | | Rapid acceleration | Gradual movement |

Comfort Settings

• Vignette during movement
• Snap vs smooth turning
• Seated vs standing modes
• Height calibration

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3. Performance Requirements

Target Metrics

| Platform | FPS | Resolution | |----------|-----|------------| | Quest 2 | 72-90 | 1832x1920 | | Quest 3 | 90-120 | 2064x2208 | | PCVR | 90 | 2160x2160+ | | PSVR2 | 90-120 | 2000x2040 |

Frame Budget

• VR requires consistent frame times
• Single dropped frame = visible judder
• 90 FPS = 11.11ms budget

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4. Interaction Principles

Controller Interaction

| Type | Use | |------|-----| | Point + click | UI, distant objects | | Grab | Manipulation | | Gesture | Magic, special actions | | Physical | Throwing, swinging |

Hand Tracking

• More immersive but less precise
• Good for: social, casual
• Challenging for: action, precision

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5. Spatial Design

World Scale

• 1 unit = 1 meter (critical)
• Objects must feel right size
• Test with real measurements

Depth Cues

| Cue | Importance | |-----|------------| | Stereo | Primary depth | | Motion parallax | Secondary | | Shadows | Grounding | | Occlusion | Layering |

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6. Anti-Patterns

| ❌ Don't | ✅ Do | |----------|-------| | Move camera without player | Player controls camera | | Drop below 90 FPS | Maintain frame rate | | Use tiny UI text | Large, readable text | | Ignore arm length | Scale to player reach |

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Remember: Comfort is not optional. Sick players don't play.